REM > BBCMOS1/SRC
REM Source for Atom MOS interface for BBC BASIC
REM Source recreation by J.G.Harston
:
SYS "OS_GetEnv" TO A$:A$=A$+" ":A$=MID$(A$,1+INSTR(A$," ",1+INSTR(A$," ",1+INSTR(A$," "))))
A%=INSTR(A$+" "," "):outfile$=LEFT$(A$,A%-1):A$=MID$(A$,A%+1):IF outfile$="":outfile$="outfile"
A%=INSTR(A$+" "," "):version$=LEFT$(A$,A%-1):A$=MID$(A$,A%+1):IF version$="":version$="1"
A%=INSTR(A$+" "," "):bugfix$ =LEFT$(A$,A%-1):A$=MID$(A$,A%+1):IF bugfix$ ="":bugfix$ ="0"
IF outfile$="":ERROR 220,"Syntax: B6502 -quit BBCMOS/src <outfile> <version> <bugfix>":END
:
PRINT "Assembling: Atom BBC MOS version ";version$
PRINT "Bugfix level: ";bugfix$
PRINT "Outfile:      ";outfile$
ON ERROR REPORT:PRINT " at line ";ERL:END
:
:
REM Note: There are lots of bugs in this code.
REM       There is overlap between BBC memory locations and Atom memory locations,
REM       eg: &FE is BBC FAULT pointer and Atom NoPrint character
REM       Error messages all have wrong error number.
REM       Unsupported calls bomb out instead of returning cleanly.
REM       Some implemented calls don't return correct results.
:
REM Memory Map
REM ----------
REM &00-&8F - BBC BASIC zero page workspace
REM
REM &98   - IRQ A store
REM &99   - IRQ X store
REM &9A
REM &9B   - CLI A store
REM &9C/D - CLI line pointer
REM &9E/F - pointer to control block or memory
REM &9E   - OSWRCH A store
REM &9F   - OSWRCH X store
REM &A0   - OSWRCH Y store
REM &A1
REM &A2/3 - OSWORD 0 control block
REM &A4/5 - OSWORD 0 text address
REM &A6   - OSWORD 0 maximum length
REM &A7   - OSWORD 0 lowest character
REM &A8   - OSWORD 0 highest character
REM
REM &B3   - screen map 0-4
REM &B4/5 - start of screen
REM &B5
REM
REM &C9/A - OSCLI dispatch address
REM
REM &DD   - Y store in OSCLI
REM &DE/F - Address of start of current line
REM &E0   - b7=VDU disabled
REM &E1
REM &E2/3
REM &E4/5 - X/Y store in VDU code
REM &E8/9 - inline text pointer
REM &EA
REM
REM &0300-4 - TIME
REM &0305-E   VDU queue
REM   &305 - &01   &11   &12    &13  &16  &17   &1F
REM   &306 - char colour mode   log  mode char   x
REM   &307 -             colour phy       b1     y
REM   &308 -                    red       b2
REM   &309 -                    grn       b3
REM   &30A -                    blu       b4
REM   &30B -                              b5
REM   &30C -                              b6
REM   &30D -                              b7
REM   &30E -                              b8
REM &030F

REM &0313/4 - PLOT vector
REM &0315
REM &0316   - VDU queue length
REM
REM &0317/8 - SOUND duration
REM &0319/A - SOUND pitch - copied to 6522 T2 at &7808 on Timer1
REM &031B/C - INKEY delay
REM &031D-F - b16-b39 of INKEY delay
REM &0320-4 - now+delay for INKEY
REM
REM &032A   - MODE
REM
REM &0400-&07FF - BBC BASIC workspace
REM
:
REM MOS entry addresses
REM -------------------
OS_CLI=&FFF7:OSBYTE=&FFF4:OSWORD=&FFF1:OSWRCH=&FFEE
OSWRCR=&FFEC:OSNEWL=&FFE7:OSASCI=&FFE3:OSRDCH=&FFE0
:
REM Vectors
REM -------
userv=&200:brkv =&202:irq1v=&204:irq2v=&206
cliv =&208:bytev=&20A:wordv=&20C:wrchv=&20E
rdchv=&210:filev=&212:argsv=&214:bgetv=&216
bputv=&218:gbpbv=&21A:findv=&21C:fscv =&21E
evntv=&220:uptv =&222:netv =&224:vduv =&226
keyv =&228:insv =&22A:remv =&22C:cnpv =&22E
ind1v=&230:ind2v=&232:ind3v=&234
:
REM I/O Addresses
REM -------------
REM &7000 - 8255
REM &7800 - 6522
:
:
BUGFIX%=VALbugfix$
DIM mcode% &1100:load%=&F000
FOR opt%=4 TO 7 STEP 3
P%=load%:O%=mcode%
[OPT opt%
\ ==============
\ OSWORD HANDLER
\ ==============
\ On entry, A =function
\           XY=>control block
\ On exit,  A,X,Y preserved if not OSWORD 0
\           control block updated
\
.LF000
CMP #&00:BEQ LF019       :\ Jump with read input line
CMP #&01:BEQ LF013       :\ Jump with =TIME
CMP #&02:BEQ LF07F       :\ Jump with TIME=
CMP #&07:BEQ LF016       :\ Jump with SOUND
OPT FNif(BUGFIX%<1)
 JMP LF0E6               :\ Otherwise, generate error - BAD, should just return
OPT FNelse
 RTS                     :\ Unrecognised OSWORD, return
OPT FNendif
\
.LF013:JMP LF090         :\ Pass on to do =TIME
.LF016:JMP LF0A1         :\ Pass on to do SOUND


\ OSWORD 0 - READ INPUT LINE
\ ========================== 
\ Bugs:
\  If line length becomes >127 chars, DEL/Ctrl-U mess up
\  Escape is printed then checked for, it shouldn't be printed
.LF019
STX &A2:STY &A3:LDY #&04
.LF01F
LDA (&A2),Y:STA &00A4,Y :\ Copy control block
DEY:BPL LF01F
.LF027
LDY #&00                :\ Line length=0
.LF029
JSR OSRDCH              :\ Wait for character
:                       :\ Should check for Escape
CMP #&15:BNE LF03E      :\ Not Ctrl-U
.LF030
DEY:BMI LF027           :\ Dec. length, restart if <0
:                       :\ *BUG* is line length>128, fails
LDA #&7F:JSR OSWRCH     :\ VDU 127
JMP LF030               :\ Loop back until all done

.LF03B
JMP LF027               :\ Nothing calls this
 
.LF03E
CMP #&7F:BNE LF04B      :\ Not DELETE
DEY:BMI LF027           :\ Dec. length, restart if <0
:                       :\ *BUG* is line length>128, fails
JSR OSWRCH              :\ VDU 127
JMP LF029               :\ Loop back for another character
 
.LF04B
JSR OSWRCH              :\ Print this character
CMP #&0D:BEQ LF070      :\ If <CR>, finish
CMP #&1B:BEQ LF079      :\ If <Esc>, finish - shouldn't have printed this
CMP &A7:BCC LF029       :\ If <charlo, loop for another character
CMP &A8:BEQ LF060       :\ If =charmax, store this character
BCS LF029               :\ If >charmax, loop for another character
.LF060
STA (&A4),Y:INY         :\ Store character, increment pointer
CPY &A6:BCC LF029       :\ If <lenmax, loop for another character
LDA #&7F:JSR OSWRCH     :\ Otherwise, delete this character
:                       :\ *BUG* if last character was nonprinting, this will fail
DEY:JMP LF029           :\ Dec. pointer and loop back

\ <cr> pressed
\ ------------
.LF070
STA (&A4),Y:JSR OSNEWL  :\ Store <cr> and print newline
LDX #&00                :\ X=&00 - Ok
CLC                     :\ CLC=ok
RTS        

\ <esc> pressed
\ -------------
.LF079
SEC                     :\ SEC=Escape
LDX #&FF                :\ X=&FF - Escape
STX &FF                 :\ Also set ESCFLAG
RTS       


\ OSWORD 2 - TIME=
\ ================ 
.LF07F
STX &9E:STY &9F         :\ &9E/F=>control block
LDY #&04                :\ Copy 5 bytes of control block
.LF085
LDA (&9E),Y:STA &0300,Y :\ Copy to TIME at &0300-&0304
DEY:BPL LF085          
LDY &9F:RTS             :\ Restore Y and return

\ OSWORD 1 - =TIME
\ ================ 
.LF090
STX &9E:STY &9F         :\ &9E/F=>control block
LDY #&04                :\ Copy 5 bytes of control block
.LF096
LDA &0300,Y:STA (&9E),Y :\ Copy from TIME at &0300-&0304
DEY:BPL LF096
LDY &9F:RTS             :\ Restore Y and return


\ OSWORD 7 - SOUND chn,vol,pitch,dur
\ ================================== 
.LF0A1
STX &9E:STY &9F         :\ &9E/F=>control block
LDY #&04                :\ Point to pitch
LDA (&9E),Y:STA &0319   :\ &319/A=pitch
INY
LDA (&9E),Y:STA &031A
INY
LDA (&9E),Y:STA &0317   :\ &317/8=duration
INY
LDA (&9E),Y:STA &0318
LDA &0319:STA &7808     :\ Store pitch.lo to 6522 T2.lo
LDA &031A:STA &7809     :\ Store pitch.hi to 6522 T2.hi
LDA #&A0:STA &780E      :\ Enable 6522 T2 IRQs to toggle Speaker 
LDY &9F:RTS             :\ Restore Y and return


\ ==============
\ OSBYTE HANDLER
\ ==============
\ On entry, A =function
\           XY=parameters
\ On exit,  A =preserved (memory calls may return a value)
\           XY=return values
\           Cy=may contain a return value
\
.LF0D2
CMP #&83:BEQ LF0FC       :\ Jump with read bottom of memory
CMP #&84:BEQ LF101       :\ Jump with read top of memory
CMP #&81:BEQ LF12B       :\ Jump with INKEY
CMP #&7E:BEQ LF0F9       :\ Jump with Escape Acknowledge
CMP #&82:BEQ LF0F8       :\ Jump with address high word
.LF0E6
OPT FNif(BUGFIX%<1)
 BRK:EQUB 254:EQUS "NOT IMPLEMENTED":EQUB 0
 \ *BUG* - should just return
OPT FNelse
 RTS
OPT FNendif

\ OSBYTE &82 - Read address high word
\ ===================================
.LF0F8
RTS                      :\ Return XY unchanged

\ OSBYTE &7E - Escape Acknoweldge
\ =============================== 
.LF0F9
JMP LF172

\ OSBYTE &83 - Read bottom of memory
\ ==================================
.LF0FC
LDX #&00:LDY #&08:RTS    :\ Return &0800
 
\ OSBYTE &84 - Read top of memory
\ ===============================
.LF101
PHA
LDA #&00:STA &9E:LDA #&08:STA &9F  :\ &9E/F=>&0800, lowest available location
LDY #&00
.LF10C
LDA (&9E),Y:EOR #&FF:STA (&9E),Y   :\ Complement byte in memory
CMP (&9E),Y:BNE LF125              :\ Doesn't match, end of RAM
EOR #&FF:STA (&9E),Y               :\ Complement it back to restore it
INY:BNE LF10C                      :\ Loop for 256 bytes
INC &9F:LDA &9F:CMP #&40:BCC LF10C :\ Scan up to &4000
.LF125
TYA:TAX:LDY &9F                    :\ X=low byte, Y=high byte
PLA:RTS                            :\ A.b7=1, indicates <&10000

\ OSBYTE &81 - INKEY
\ ==================
.LF12B
STX &031B:STY &031C                 :\ Store INKEY countdown time
LDX #&00
STX &031F:STX &031E:STX &031D       :\ Set b16-b39 of INKEY delay to zero
.LF13C
LDY #&04:CLC                        :\ Five bytes to add
.LF13F
LDA &0300,X:ADC &031B,X:STA &0320,X :\ &320-4 = TIME+INKEY delay
INX:DEY:BPL LF13F
.LF14C
JSR LFE4A:BCC LF162                 :\ Test keyboard, jump if key pressed
LDX #&04                            :\ Compare five bytes
.LF153
LDA &0320,X:CMP &0300,X             :\ Compare TIME with INKEY timeout
BMI LF16A                           :\ Timed out, jump to exit
BNE LF14C                           :\ Not the same, loop back
DEX:BPL LF153                       :\ Loop to test all five bytes
BMI LF16A                           :\ All bytes same, timed out
:
\ Key pressed
\ -----------
.LF162
JSR LF16E        :\ Convert keypress
TAX              :\ X=keypress
LDY #&00         :\ Y=&00 - Ok
CLC:RTS          :\ CLC=Ok, and return

.LF16A
LDY #&FF:SEC:RTS :\ Y=&FF, SEC = Timed out
 
.LF16E
PHP:JMP LFE8A    :\ Push flags, jump to convert keypress

 
\ OSBYTE &7E - Escape Acknowledge
\ =============================== 
.LF171
OPT FNif(BUGFIX%>0)
 LDX &FF                :\ X=old Escape state
OPT FNendif
.LF172
LDA &FF:BPL LF17C       :\ No pending Escape, exit
JSR LF17D:JMP LF172     :\ Update Escape state, loop until no Escape
.LF17C
RTS                     :\ **BUG** Should return previous Escape state in X

\ Update Escape state by checking for Escape key pressed
\ ------------------------------------------------------
.LF17D
LDA &7000:PHA                 :\ Get keyboard column
AND #&F0:STA &7000            :\ Select keyboard column 0
LDA &7001:AND #&20:BEQ LF191  :\ Read keyboard row, jump if Escape pressed
LDA #&00:BPL LF1A0            :\ Set 'No Escape'

\ Escape pressed
.LF191
LDA #&20:STA &780E            :\ Disable VIA T2 IRQs - stop toggling speaker
LDA #&00:STA &0317:STA &0318  :\ Clear SOUND duration to cancel sound
LDA #&FF                      :\ Set 'Escape pending'
.LF1A0
STA &FF                       :\ Set Escape state
PLA:STA &7000:RTS             :\ Restore keyboard column


\ 6522 INTERUPT
\ =============
.LF1A7
AND #&40:BNE LF1C2           :\ Jump if Timer1 interupt

\ 6522 Timer2 Interupt
\ -------------------- 
LDA &7002:EOR #&04:STA &7002 :\ Toggle Speaker bit
LDA &0319:STA &7808          :\ Copy SOUND pitch to T2 latches
LDA &031A:STA &7809          :\ 
LDA &98:RTI                  :\ Restore A and return

\ 6522 Timer1 Interupt - 100Hz timer
\ ----------------------------------
.LF1C2
STX &99:JSR LF17D             :\ Update Escape state
LDA &0317:ORA &0318:BEQ LF1E7 :\ If SOUND duration is zero, jump to continue
LDA &0317:BNE LF1D7:DEC &0318 :\ Decrement SOUND duration
.LF1D7
DEC &0317
LDA &0317:ORA &0318:BNE LF1E7 :\ If SOUND duration not zero, jump to continue
LDA #&20:STA &780E            :\ Disable 6522 T2 IRQs, stop toggling Speaker
.LF1E7
LDX #&00                      :\ Increment 5-byte TIME
.LF1E9
INC &0300,X:INX:CPX #&05:BEQ LF1F6
LDA &02FF,X:BEQ LF1E9
.LF1F6
LDX &99:LDA &7804             :\ Reset 6522 T1.lo counter
LDA &98:RTI                   :\ Restore A and return
 
.LF1FE
LDX #&03        :\ F1FE= A2 03       ".
.LF200
LDA &030F,X     :\ F200= BD 0F 03    =..
STA &B3,X       :\ F203= 95 B3       .3
DEX             :\ F205= CA          J
BPL LF200       :\ F206= 10 F8       .x
LDA &030E       :\ F208= AD 0E 03    -..
AND #&04        :\ F20B= 29 04       ).
BNE LF222       :\ F20D= D0 13       P.
LDX #&02        :\ F20F= A2 02       ".
.LF211
CLC             :\ F211= 18          .
LDA &BB,X       :\ F212= B5 BB       5;
ADC &B3,X       :\ F214= 75 B3       u3
STA &BB,X       :\ F216= 95 BB       .;
LDA &BC,X       :\ F218= B5 BC       5<
ADC &B4,X       :\ F21A= 75 B4       u4
STA &BC,X       :\ F21C= 95 BC       .<
DEX             :\ F21E= CA          J
DEX             :\ F21F= CA          J
BPL LF211       :\ F220= 10 EF       .o
.LF222
LDX #&03        :\ F222= A2 03       ".
.LF224
LDA &BB,X       :\ F224= B5 BB       5;
STA &030F,X     :\ F226= 9D 0F 03    ...
DEX             :\ F229= CA          J
BPL LF224       :\ F22A= 10 F8       .x
LDA &030E       :\ F22C= AD 0E 03    -..
AND #&03        :\ F22F= 29 03       ).
BEQ LF23F       :\ F231= F0 0C       p.
STA &BF         :\ F233= 85 BF       .?
LDA &030E       :\ F235= AD 0E 03    -..
AND #&08        :\ F238= 29 08       ).
BEQ LF240       :\ F23A= F0 04       p.
JSR LF301       :\ F23C= 20 01 F3     .s
.LF23F
RTS             :\ F23F= 60          `
 
.LF240
LDX #&02        :\ F240= A2 02       ".
.LF242
SEC             :\ F242= 38          8
LDA &BB,X       :\ F243= B5 BB       5;
SBC &B3,X       :\ F245= F5 B3       u3
LDY &B3,X       :\ F247= B4 B3       43
STY &BB,X       :\ F249= 94 BB       .;
STA &B3,X       :\ F24B= 95 B3       .3
LDY &B4,X       :\ F24D= B4 B4       44
LDA &BC,X       :\ F24F= B5 BC       5<
SBC &B4,X       :\ F251= F5 B4       u4
STY &BC,X       :\ F253= 94 BC       .<
STA &B4,X       :\ F255= 95 B4       .4
STA &B7,X       :\ F257= 95 B7       .7
BPL LF268       :\ F259= 10 0D       ..
LDA #&00        :\ F25B= A9 00       ).
SEC             :\ F25D= 38          8
SBC &B3,X       :\ F25E= F5 B3       u3
STA &B3,X       :\ F260= 95 B3       .3
LDA #&00        :\ F262= A9 00       ).
SBC &B4,X       :\ F264= F5 B4       u4
STA &B4,X       :\ F266= 95 B4       .4
.LF268
DEX             :\ F268= CA          J
DEX             :\ F269= CA          J
BPL LF242       :\ F26A= 10 D6       .V
LDA &B5         :\ F26C= A5 B5       %5
CMP &B3         :\ F26E= C5 B3       E3
LDA &B6         :\ F270= A5 B6       %6
SBC &B4         :\ F272= E5 B4       e4
BCC LF2A5       :\ F274= 90 2F       ./
LDA #&00        :\ F276= A9 00       ).
SBC &B5         :\ F278= E5 B5       e5
STA &B8         :\ F27A= 85 B8       .8
LDA #&00        :\ F27C= A9 00       ).
SBC &B6         :\ F27E= E5 B6       e6
SEC             :\ F280= 38          8
ROR A           :\ F281= 6A          j
STA &BA         :\ F282= 85 BA       .:
ROR &B8         :\ F284= 66 B8       f8
.LF286
JSR LF301       :\ F286= 20 01 F3     .s
LDA &BD         :\ F289= A5 BD       %=
CMP &0311       :\ F28B= CD 11 03    M..
BNE LF298       :\ F28E= D0 08       P.
LDA &BE         :\ F290= A5 BE       %>
CMP &0312       :\ F292= CD 12 03    M..
BNE LF298       :\ F295= D0 01       P.
.LF297
RTS             :\ F297= 60          `
 
.LF298
JSR LF2DE       :\ F298= 20 DE F2     ^r
LDA &BA         :\ F29B= A5 BA       %:
BMI LF286       :\ F29D= 30 E7       0g
JSR LF2CD       :\ F29F= 20 CD F2     Mr
JMP LF286       :\ F2A2= 4C 86 F2    L.r
 
.LF2A5
LDA &B4         :\ F2A5= A5 B4       %4
LSR A           :\ F2A7= 4A          J
STA &BA         :\ F2A8= 85 BA       .:
LDA &B3         :\ F2AA= A5 B3       %3
ROR A           :\ F2AC= 6A          j
STA &B8         :\ F2AD= 85 B8       .8
.LF2AF
JSR LF301       :\ F2AF= 20 01 F3     .s
LDA &BB         :\ F2B2= A5 BB       %;
CMP &030F       :\ F2B4= CD 0F 03    M..
BNE LF2C0       :\ F2B7= D0 07       P.
LDA &BC         :\ F2B9= A5 BC       %<
CMP &0310       :\ F2BB= CD 10 03    M..
BEQ LF297       :\ F2BE= F0 D7       pW
.LF2C0
JSR LF2CD       :\ F2C0= 20 CD F2     Mr
LDA &BA         :\ F2C3= A5 BA       %:
BPL LF2AF       :\ F2C5= 10 E8       .h
JSR LF2DE       :\ F2C7= 20 DE F2     ^r
JMP LF2AF       :\ F2CA= 4C AF F2    L/r
 
.LF2CD
SEC             :\ F2CD= 38          8
LDA &B8         :\ F2CE= A5 B8       %8
SBC &B5         :\ F2D0= E5 B5       e5
STA &B8         :\ F2D2= 85 B8       .8
LDA &BA         :\ F2D4= A5 BA       %:
SBC &B6         :\ F2D6= E5 B6       e6
STA &BA         :\ F2D8= 85 BA       .:
LDX #&00        :\ F2DA= A2 00       ".
BEQ LF2ED       :\ F2DC= F0 0F       p.
.LF2DE
CLC             :\ F2DE= 18          .
LDA &B8         :\ F2DF= A5 B8       %8
ADC &B3         :\ F2E1= 65 B3       e3
STA &B8         :\ F2E3= 85 B8       .8
LDA &BA         :\ F2E5= A5 BA       %:
ADC &B4         :\ F2E7= 65 B4       e4
STA &BA         :\ F2E9= 85 BA       .:
LDX #&02        :\ F2EB= A2 02       ".
.LF2ED
LDA &B7,X       :\ F2ED= B5 B7       57
BPL LF2FA       :\ F2EF= 10 09       ..
LDA &BB,X       :\ F2F1= B5 BB       5;
BNE LF2F7       :\ F2F3= D0 02       P.
DEC &BC,X       :\ F2F5= D6 BC       V<
.LF2F7
DEC &BB,X       :\ F2F7= D6 BB       V;
.LF2F9
RTS             :\ F2F9= 60          `
 
.LF2FA
INC &BB,X       :\ F2FA= F6 BB       v;
BNE LF2F9       :\ F2FC= D0 FB       P{
INC &BC,X       :\ F2FE= F6 BC       v<
RTS             :\ F300= 60          `
 
\ Call the plot subroutine for the current screen mode
.LF301
JMP (&0313)     :\ F301= 6C 13 03    l..

\ Set up screen mode
\ ==================
\ Note, VDU driver only supports MODE 7
\ 
.LF304
LDY #&00
LDA #&07:AND &B3:STA &B3  :\ Ensure MODE is 0-7
STA &032A
LDA #&07:SEC:SBC &B3      :\ A=7-MODE
BEQ LF34A                 :\ Jump with MODE 7
CMP #&05:BMI LF31C        :\ Jump with 
LDA #&04
.LF31C
LDX #&40           :\ X=&40xx, start of screen memory
STX &B5:STY &B4    :\ &B4/5=>start of screen memory
STA &B3            :\ &B3=screen map
TAX:LDA LF357-1,X  :\ Get address of screen memory for this screen map
TAX                :\ X=end of screen memory
TYA                :\ Y=0
.LF32A
STA (&B4),Y:DEY    :\ Clear video memory
BNE LF32A          :\ Loop for 256 bytes
INC &B5            :\ Step to next 256 bytes
CPX &B5:BNE LF32A  :\ Loop to end of video memory

\ Set up PLOT and 6847
\ --------------------
.LF335
LDY &B3               :\ Get MODE *BUG* in MODE 7 this is 7
LDA LF360,Y:STA &0314 :\ Set up PLOT vector
LDA LF35B,Y:STA &0313
LDA LF365,Y:STA &7000 :\ Set screen geometry
RTS

\ Set up MODE 7
\ -------------
.LF34A
LDA #&40        :\ Atom ' ' character
.LF34C
STA &4000,Y     :\ Store in 512-byte screen RAM
STA &4100,Y
DEY:BNE LF34C   :\ Loop to clear memory
BEQ LF335       :\ Jump back to set VDU variables

\ Address of end of screen memory
\ -------------------------------
.LF357
EQUB &44        :\ MODE 6   - &4000-&4400
EQUB &46        :\ MODE 5   - &4000-&4600
EQUB &4C        :\ MODE 4   - &4000-&4C00
EQUB &58        :\ MODE 3-0 - &4000-&5800

\ PLOT vector table
\ -----------------
.LF35B
EQUB LF36A AND 255 :\ MODE 6
EQUB LF3C3 AND 255 :\ MODE 5
EQUB LF3DC AND 255 :\ MODE 4
EQUB LF3F5 AND 255
EQUB LF432 AND 255

.LF360
EQUB LF36A DIV 256
EQUB LF3C3 DIV 256
EQUB LF3DC DIV 256
EQUB LF3F5 DIV 256
EQUB LF432 DIV 256

\ 6847 screen geometry settings
\ -----------------------------
.LF365
EQUB &00
EQUB &30
EQUB &70
EQUB &B0
EQUB &F0

\ MODE 7 - select screen type 0 (text)
\ ====================================
.LF36A
LDA &BC         :\ F36A= A5 BC       %<
ORA &BE         :\ F36C= 05 BE       .>
BNE LF3C2       :\ F36E= D0 52       PR
LDA &BB         :\ F370= A5 BB       %;
CMP #&40        :\ F372= C9 40       I@
BCS LF3C2       :\ F374= B0 4C       0L
LSR A           :\ F376= 4A          J
STA &C0         :\ F377= 85 C0       .@
LDA #&2F        :\ F379= A9 2F       )/
SEC             :\ F37B= 38          8
SBC &BD         :\ F37C= E5 BD       e=
CMP #&30        :\ F37E= C9 30       I0
BCS LF3C2       :\ F380= B0 40       0@
LDX #&FF        :\ F382= A2 FF       ".
SEC             :\ F384= 38          8
.LF385
INX             :\ F385= E8          h
SBC #&03        :\ F386= E9 03       i.
BCS LF385       :\ F388= B0 FB       0{
ADC #&03        :\ F38A= 69 03       i.
STA &C2         :\ F38C= 85 C2       .B
TXA             :\ F38E= 8A          .
ASL A           :\ F38F= 0A          .
ASL A           :\ F390= 0A          .
ASL A           :\ F391= 0A          .
ASL A           :\ F392= 0A          .
ASL A           :\ F393= 0A          .
ORA &C0         :\ F394= 05 C0       .@
STA &C0         :\ F396= 85 C0       .@
LDA #&40        :\ F398= A9 40       )@
ADC #&00        :\ F39A= 69 00       i.
STA &C1         :\ F39C= 85 C1       .A
LDA &BB         :\ F39E= A5 BB       %;
LSR A           :\ F3A0= 4A          J
LDA &C2         :\ F3A1= A5 C2       %B
ROL A           :\ F3A3= 2A          *
TAY             :\ F3A4= A8          (
LDA LF453,Y     :\ F3A5= B9 53 F4    9St
.LF3A8
LDY #&00        :\ F3A8= A0 00        .
LDX &BF         :\ F3AA= A6 BF       &?
DEX             :\ F3AC= CA          J
BEQ LF3BE       :\ F3AD= F0 0F       p.
DEX             :\ F3AF= CA          J
BEQ LF3B9       :\ F3B0= F0 07       p.
EOR #&FF        :\ F3B2= 49 FF       I.
AND (&C0),Y     :\ F3B4= 31 C0       1@
STA (&C0),Y     :\ F3B6= 91 C0       .@
RTS             :\ F3B8= 60          `
 
.LF3B9
EOR (&C0),Y     :\ F3B9= 51 C0       Q@
STA (&C0),Y     :\ F3BB= 91 C0       .@
RTS             :\ F3BD= 60          `
 
.LF3BE
ORA (&C0),Y     :\ F3BE= 11 C0       .@
STA (&C0),Y     :\ F3C0= 91 C0       .@
.LF3C2
RTS             :\ F3C2= 60          `

\ MODE 6 - select screen type 1
\ =============================
.LF3C3
LDA &BC         :\ F3C3= A5 BC       %<
ORA &BE         :\ F3C5= 05 BE       .>
BNE LF3C2       :\ F3C7= D0 F9       Py
LDA &BB         :\ F3C9= A5 BB       %;
BMI LF3C2       :\ F3CB= 30 F5       0u
LSR A           :\ F3CD= 4A          J
LSR A           :\ F3CE= 4A          J
LSR A           :\ F3CF= 4A          J
STA &C0         :\ F3D0= 85 C0       .@
LDA #&3F        :\ F3D2= A9 3F       )?
SEC             :\ F3D4= 38          8
SBC &BD         :\ F3D5= E5 BD       e=
CMP #&40        :\ F3D7= C9 40       I@
BCC LF40D       :\ F3D9= 90 32       .2
RTS             :\ F3DB= 60          `

\ MODE 5 - select screen type 2
\ =============================
.LF3DC 
LDA &BC         :\ F3DC= A5 BC       %<
ORA &BE         :\ F3DE= 05 BE       .>
BNE LF3C2       :\ F3E0= D0 E0       P`
LDA &BB         :\ F3E2= A5 BB       %;
BMI LF3C2       :\ F3E4= 30 DC       0\
LSR A           :\ F3E6= 4A          J
LSR A           :\ F3E7= 4A          J
LSR A           :\ F3E8= 4A          J
STA &C0         :\ F3E9= 85 C0       .@
LDA #&5F        :\ F3EB= A9 5F       )_
SEC             :\ F3ED= 38          8
SBC &BD         :\ F3EE= E5 BD       e=
CMP #&60        :\ F3F0= C9 60       I`
BCC LF40D       :\ F3F2= 90 19       ..
.LF3F4
RTS             :\ F3F4= 60          `

\ MODE 4 - select screen type 3
\ =============================
.LF3F5 
LDA &BC         :\ F3F5= A5 BC       %<
ORA &BE         :\ F3F7= 05 BE       .>
BNE LF3C2       :\ F3F9= D0 C7       PG
LDA &BB         :\ F3FB= A5 BB       %;
BMI LF3C2       :\ F3FD= 30 C3       0C
LSR A           :\ F3FF= 4A          J
LSR A           :\ F400= 4A          J
LSR A           :\ F401= 4A          J
STA &C0         :\ F402= 85 C0       .@
LDA #&BF        :\ F404= A9 BF       )?
SEC             :\ F406= 38          8
SBC &BD         :\ F407= E5 BD       e=
CMP #&C0        :\ F409= C9 C0       I@
BCS LF3C2       :\ F40B= B0 B5       05
.LF40D
LDY #&00        :\ F40D= A0 00        .
STY &C1         :\ F40F= 84 C1       .A
.LF411
ASL A           :\ F411= 0A          .
ROL &C1         :\ F412= 26 C1       &A
ASL A           :\ F414= 0A          .
ROL &C1         :\ F415= 26 C1       &A
ASL A           :\ F417= 0A          .
ROL &C1         :\ F418= 26 C1       &A
ASL A           :\ F41A= 0A          .
ROL &C1         :\ F41B= 26 C1       &A
ADC &C0         :\ F41D= 65 C0       e@
STA &C0         :\ F41F= 85 C0       .@
LDA &C1         :\ F421= A5 C1       %A
ADC #&40        :\ F423= 69 40       i@
STA &C1         :\ F425= 85 C1       .A
LDA &BB         :\ F427= A5 BB       %;
AND #&07        :\ F429= 29 07       ).
TAY             :\ F42B= A8          (
LDA LF451,Y     :\ F42C= B9 51 F4    9Qt
JMP LF3A8       :\ F42F= 4C A8 F3    L(s

\ MODE 0-3 - select screen type 4
\ ===============================
.LF432 
LDA &BC         :\ F432= A5 BC       %<
ORA &BE         :\ F434= 05 BE       .>
BNE LF3F4       :\ F436= D0 BC       P<
LDA &BB         :\ F438= A5 BB       %;
LSR A           :\ F43A= 4A          J
LSR A           :\ F43B= 4A          J
LSR A           :\ F43C= 4A          J
STA &C0         :\ F43D= 85 C0       .@
LDA #&BF        :\ F43F= A9 BF       )?
SEC             :\ F441= 38          8
SBC &BD         :\ F442= E5 BD       e=
CMP #&C0        :\ F444= C9 C0       I@
BCS LF3F4       :\ F446= B0 AC       0,
LDY #&00        :\ F448= A0 00        .
STY &C1         :\ F44A= 84 C1       .A
ASL A           :\ F44C= 0A          .
ROL &C1         :\ F44D= 26 C1       &A
BPL LF411       :\ F44F= 10 C0       .@

\ Bitmap table
\ ============
.LF451
EQUB &80:EQUB &40
.LF453
EQUB &20:EQUB &10
EQUB &08:EQUB &04
EQUB &02:EQUB &01

\ ONLY CALLED FROM UNREACHABLE CODE

.LF459
AND #&03        :\ F459= 29 03          .
TAY             :\ F45B= A8          (
LDA LF49D,Y     :\ F45C= B9 9D F4    9.t
STA &0315       :\ F45F= 8D 15 03    ...
LDA &7000       :\ F462= AD 00 70    -.p
AND #&F0        :\ F465= 29 F0       )p
CMP #&70        :\ F467= C9 70       Ip
BNE LF477       :\ F469= D0 0C       P.
LDA #&00        :\ F46B= A9 00       ).
TAY             :\ F46D= A8          (
.LF46E
STA &4600,Y     :\ F46E= 99 00 46    ..F
STA &4700,Y     :\ F471= 99 00 47    ..G
DEY             :\ F474= 88          .
BNE LF46E       :\ F475= D0 F7       Pw
.LF477
LDA &7000       :\ F477= AD 00 70    -.p
AND #&DF        :\ F47A= 29 DF       )_
STA &7000       :\ F47C= 8D 00 70    ..p
ROL A           :\ F47F= 2A          *
ROL A           :\ F480= 2A          *
ROL A           :\ F481= 2A          *
AND #&03        :\ F482= 29 03       ).
TAY             :\ F484= A8          (
LDA LF491,Y     :\ F485= B9 91 F4    9.t
STA &0313       :\ F488= 8D 13 03    ...
LDA LF495,Y     :\ F48B= B9 95 F4    9.t
STA &0314       :\ F48E= 8D 14 03    ...

\ TODO BAD STUFF HAPPENS HERE !!!
.LF491
EQUB LF4A1 AND 255
EQUB LF4BF AND 255
EQUB LF4D7 AND 255
EQUB LF506 AND 255

.LF495
EQUB LF4A1 DIV 256
EQUB LF4BF DIV 256
EQUB LF4D7 DIV 256
EQUB LF506 DIV 256

.LF499
EQUB &3F        :\ F499= 3F          ?
EQUB &CF        :\ F49A= CF          O
EQUB &F3        :\ F49B= F3          s
EQUB &FC        :\ F49C= FC          |

.LF49D
EQUB &00        :\ F49D= 00          .
EQUB &55        :\ F49E= 55          U
EQUB &AA        :\ F49E= AA          *
EQUB &FF        :\ F4A0= FF          .

.LF4A1
LDA &BC         :\ F4A1= A5 BC       %<
ORA &BE         :\ F4A3= 05 BE       .>
BNE LF4EE       :\ F4A5= D0 47       PG
LDA &BB         :\ F4A7= A5 BB       %;
CMP #&40        :\ F4A9= C9 40       I@
BCS LF4EE       :\ F4AB= B0 41       0A
LSR A           :\ F4AD= 4A          J
LSR A           :\ F4AE= 4A          J
STA &C0         :\ F4AF= 85 C0       .@
LDY #&00        :\ F4B1= A0 00        .
STY &C1         :\ F4B3= 84 C1       .A
LDA #&3F        :\ F4B5= A9 3F       )?
SEC             :\ F4B7= 38          8
SBC &BD         :\ F4B8= E5 BD       e=
CMP #&40        :\ F4BA= C9 40       I@
BCC LF524       :\ F4BC= 90 66       .f
RTS             :\ F4BE= 60          `

.LF4BF 
LDA &BC         :\ F4BF= A5 BC       %<
ORA &BE         :\ F4C1= 05 BE       .>
BNE LF4EE       :\ F4C3= D0 29       P)
LDA &BB         :\ F4C5= A5 BB       %;
BMI LF4EE       :\ F4C7= 30 25       0%
LSR A           :\ F4C9= 4A          J
LSR A           :\ F4CA= 4A          J
STA &C0         :\ F4CB= 85 C0       .@
LDA #&3F        :\ F4CD= A9 3F       )?
SEC             :\ F4CF= 38          8
SBC &BD         :\ F4D0= E5 BD       e=
CMP #&40        :\ F4D2= C9 40       I@
BCC LF51D       :\ F4D4= 90 47       .G
RTS             :\ F4D6= 60          `

.LF4D7 
LDA &BC         :\ F4D7= A5 BC       %<
ORA &BE         :\ F4D9= 05 BE       .>
BNE LF4EE       :\ F4DB= D0 11       P.
LDA &BB         :\ F4DD= A5 BB       %;
BMI LF4EE       :\ F4DF= 30 0D       0.
LSR A           :\ F4E1= 4A          J
LSR A           :\ F4E2= 4A          J
STA &C0         :\ F4E3= 85 C0       .@
LDA #&5F        :\ F4E5= A9 5F       )_
SEC             :\ F4E7= 38          8
SBC &BD         :\ F4E8= E5 BD       e=
CMP #&60        :\ F4EA= C9 60       I`
BCC LF51D       :\ F4EC= 90 2F       ./
.LF4EE
RTS             :\ F4EE= 60          `
 
.LF4EF
EOR #&FF        :\ F4EF= 49 FF       I.
EOR (&C0),Y     :\ F4F1= 51 C0       Q@
STA (&C0),Y     :\ F4F3= 91 C0       .@
RTS             :\ F4F5= 60          `
 
.LF4F6
TAX             :\ F4F6= AA          *
AND (&C0),Y     :\ F4F7= 31 C0       1@
STA (&C0),Y     :\ F4F9= 91 C0       .@
TXA             :\ F4FB= 8A          .
EOR #&FF        :\ F4FC= 49 FF       I.
AND &0315       :\ F4FE= 2D 15 03    -..
ORA (&C0),Y     :\ F501= 11 C0       .@
STA (&C0),Y     :\ F503= 91 C0       .@
RTS             :\ F505= 60          `

.LF506
LDA &BC         :\ F506= A5 BC       %<
ORA &BE         :\ F508= 05 BE       .>
BNE LF4EE       :\ F50A= D0 E2       Pb
LDA &BB         :\ F50C= A5 BB       %;
BMI LF4EE       :\ F50E= 30 DE       0^
LSR A           :\ F510= 4A          J
LSR A           :\ F511= 4A          J
STA &C0         :\ F512= 85 C0       .@
LDA #&BF        :\ F514= A9 BF       )?
SEC             :\ F516= 38          8
SBC &BD         :\ F517= E5 BD       e=
CMP #&C0        :\ F519= C9 C0       I@
BCS LF4EE       :\ F51B= B0 D1       0Q
.LF51D
LDY #&00        :\ F51D= A0 00        .
STY &C1         :\ F51F= 84 C1       .A
ASL A           :\ F521= 0A          .
ROL &C1         :\ F522= 26 C1       &A
.LF524
ASL A           :\ F524= 0A          .
ROL &C1         :\ F525= 26 C1       &A
ASL A           :\ F527= 0A          .
ROL &C1         :\ F528= 26 C1       &A
ASL A           :\ F52A= 0A          .
ROL &C1         :\ F52B= 26 C1       &A
ASL A           :\ F52D= 0A          .
ROL &C1         :\ F52E= 26 C1       &A
ADC &C0         :\ F530= 65 C0       e@
STA &C0         :\ F532= 85 C0       .@
LDA &C1         :\ F534= A5 C1       %A
ADC #&80        :\ F536= 69 80       i.
STA &C1         :\ F538= 85 C1       .A
LDA &BB         :\ F53A= A5 BB       %;
AND #&03        :\ F53C= 29 03       ).
TAX             :\ F53E= AA          *
LDA LF499,X     :\ F53F= BD 99 F4    =.t
LDX &BF         :\ F542= A6 BF       &?
DEX             :\ F544= CA          J
BEQ LF4F6       :\ F545= F0 AF       p/
DEX             :\ F547= CA          J
BEQ LF4EF       :\ F548= F0 A5       p%
AND (&C0),Y     :\ F54A= 31 C0       1@
STA (&C0),Y     :\ F54C= 91 C0       .@
RTS             :\ F54E= 60          `


\ ==============
\ OSWRCH HANDLER
\ ==============
\ On entry, A=character to output
\ On exit,  A,X,Y preserved
\           On the BBC flags also preserved
\
.LF54F 
STY &A0:STX &9F:STA &9E   :\ Save registers
LDX &0316:BEQ LF57F       :\ Jump if VDU queue empty
STA &0305,X:DEX:STX &0316 :\ Store byte in VDU queue
BNE LF578                 :\ Queue not empty, exit
LDA &0305                 :\ Get VDU command
CMP #&16:BEQ LF5D1        :\ Jump with MODE
CMP #&19:BEQ LF575        :\ Jump with PLOT
CMP #&1F:BNE LF578        :\ Exit if not TAB
JMP LF791                 :\ Jump with TAB
.LF575
JMP LF614                 :\ Jump onwards for PLOT
.LF578
LDY &A0:LDX &9F:LDA &9E   :\ Restore registers
RTS                       :\ and return

\ VDU queue empty, must be character or first byte of command
\ -----------------------------------------------------------
.LF57F
CMP #&16:BNE LF58E        :\ Jump if not VDU 22, start of MODE

\ One more byte needed
\ --------------------
.LF583
LDX #&01:STX &0316        :\ One more byte needed
STA &0305:JMP LF578       :\ Save command, and exit
.LF58E
CMP #&19:BNE LF59D        :\ Jump if not VDU 25, start of PLOT
LDX #&05:STX &0316        :\ Five more bytes needed
STA &0305:JMP LF578       :\ Save command, and exit
.LF59D
CMP #&12:BEQ LF583        :\ Jump if VDU 18, COLOUR, to collect one byte
CMP #&1F:BNE LF5B0        :\ Jump if not VDU 31, TAB
LDX #&02:STX &0316        :\ Two more bytes needed
STA &0305:JMP LF578       :\ Save command, and exit
.LF5B0
CMP #&10:BNE LF5BD        :\ Jump if not VDU 16 - CLG
LDA &032A:STA &0306
JMP LF5D1                 :\ Continue into MODE

\ All VDU command sequences checked for, must be single character
\ --------------------------------------------------------------- 
.LF5BD
LDY &A0:LDX &9F:LDA &9E   :\ Get registers back
CMP #&61:BMI LF5CE        :\ Not a lower-case character
CMP #&7B:BPL LF5CE        
SEC:SBC #&20              :\ Force lower case to upper case
.LF5CE
JMP LFE2B                 :\ Jump to Atom Kernel VDU code


\ VDU 22,n - MODE
\ =============== 
.LF5D1
LDA &0306:STA &B3         :\ Get MODE parameter, set current MODE
JSR LF304                 :\ Set up VDU hardware
LDA &B3                   :\ Get current MODE
CMP #&07:BNE LF5ED        :\ Not MODE 7, move graphics cursor to 0,0
JSR LF578                 :\ Get original registers back
LDA #&0C:JSR OSWRCH       :\ Do CLS, overwriting register store
JSR LF578                 :\ Get registers back from register store
LDA #&07:RTS              :\ Restore A to 7 and return

\ Do MOVE 0,0 to move graphics cursor to (0,0)
\ -------------------------------------------- 
.LF5ED
JSR LF578                 :\ Get original registers back
PHA                       :\ Save A
LDA #&19:JSR OSWRCH       :\ PLOT
LDA #&04:JSR OSWRCH       :\ PLOT 4 = MOVE
LDA #&00                  :\ Do MOVE 0,0
JSR OSWRCH:JSR OSWRCH     :\ Send X=0
JSR OSWRCH:JSR OSWRCH     :\ Send Y=0
PLA:RTS                   :\ Restore A and return

 
\ UNREACHABLE

LDA &0306       :\ F60B= AD 06 03    -..
JSR LF459       :\ F60E= 20 59 F4     Yt
JMP LF578       :\ F611= 4C 78 F5    Lxu
 
.LF614
LDA &030A       :\ F614= AD 0A 03    -..
CMP #&40        :\ F617= C9 40       I@
BCC LF61D       :\ F619= 90 02       ..
SBC #&38        :\ F61B= E9 38       i8
.LF61D
AND #&1F        :\ F61D= 29 1F       ).
STA &030E       :\ F61F= 8D 0E 03    ...
LDA #&00        :\ F622= A9 00       ).
STA &032B       :\ F624= 8D 2B 03    .+.
LDA &0308       :\ F627= AD 08 03    -..
BPL LF636       :\ F62A= 10 0A       ..
LDX #&03        :\ F62C= A2 03       ".
JSR LF6FA       :\ F62E= 20 FA F6     zv
LDA #&FF        :\ F631= A9 FF       ).
STA &032B       :\ F633= 8D 2B 03    .+.
.LF636
LDA #&00        :\ F636= A9 00       ).
STA &BB         :\ F638= 85 BB       .;
STA &BC         :\ F63A= 85 BC       .<
LDA &0309       :\ F63C= AD 09 03    -..
.LF63F
SEC             :\ F63F= 38          8
SBC #&05        :\ F640= E9 05       i.
BCS LF649       :\ F642= B0 05       0.
DEC &0308       :\ F644= CE 08 03    N..
BMI LF651       :\ F647= 30 08       0.
.LF649
INC &BB         :\ F649= E6 BB       f;
BNE LF63F       :\ F64B= D0 F2       Pr
INC &BC         :\ F64D= E6 BC       f<
BNE LF63F       :\ F64F= D0 EE       Pn
.LF651
LDA &7000       :\ F651= AD 00 70    -.p
AND #&F0        :\ F654= 29 F0       )p
CMP #&F0        :\ F656= C9 F0       Ip
BEQ LF666       :\ F658= F0 0C       p.
CMP #&20        :\ F65A= C9 20       I 
BCS LF662       :\ F65C= B0 04       0.
LSR &BC         :\ F65E= 46 BC       F<
ROR &BB         :\ F660= 66 BB       f;
.LF662
LSR &BC         :\ F662= 46 BC       F<
ROR &BB         :\ F664= 66 BB       f;
.LF666
LDA &032B       :\ F666= AD 2B 03    -+.
BPL LF670       :\ F669= 10 05       ..
LDX #&08        :\ F66B= A2 08       ".
JSR LF70C       :\ F66D= 20 0C F7     .w
.LF670
LDA #&00        :\ F670= A9 00       ).
STA &032C       :\ F672= 8D 2C 03    .,.
LDA &0306       :\ F675= AD 06 03    -..
BPL LF684       :\ F678= 10 0A       ..
LDX #&01        :\ F67A= A2 01       ".
JSR LF6FA       :\ F67C= 20 FA F6     zv
LDA #&FF        :\ F67F= A9 FF       ).
STA &032C       :\ F681= 8D 2C 03    .,.
.LF684
LDA &7000       :\ F684= AD 00 70    -.p
AND #&F0        :\ F687= 29 F0       )p
CMP #&10        :\ F689= C9 10       I.
BEQ LF695       :\ F68B= F0 08       p.
CMP #&30        :\ F68D= C9 30       I0
BEQ LF695       :\ F68F= F0 04       p.
CMP #&50        :\ F691= C9 50       IP
BNE LF6AA       :\ F693= D0 15       P.
.LF695
LDA &0307       :\ F695= AD 07 03    -..
STA &BD         :\ F698= 85 BD       .=
LDA &0306       :\ F69A= AD 06 03    -..
STA &BE         :\ F69D= 85 BE       .>
LSR &BE         :\ F69F= 46 BE       F>
ROR &BD         :\ F6A1= 66 BD       f=
LSR &BE         :\ F6A3= 46 BE       F>
ROR &BD         :\ F6A5= 66 BD       f=
JMP LF6E2       :\ F6A7= 4C E2 F6    Lbv
 
.LF6AA
LDA &0307       :\ F6AA= AD 07 03    -..
ASL A           :\ F6AD= 0A          .
STA &BD         :\ F6AE= 85 BD       .=
LDA &0306       :\ F6B0= AD 06 03    -..
ROL A           :\ F6B3= 2A          *
STA &BE         :\ F6B4= 85 BE       .>
CLC             :\ F6B6= 18          .
LDA &BD         :\ F6B7= A5 BD       %=
ADC &0307       :\ F6B9= 6D 07 03    m..
STA &BD         :\ F6BC= 85 BD       .=
LDA &BE         :\ F6BE= A5 BE       %>
ADC &0306       :\ F6C0= 6D 06 03    m..
STA &BE         :\ F6C3= 85 BE       .>
LSR &BE         :\ F6C5= 46 BE       F>
ROR &BD         :\ F6C7= 66 BD       f=
LSR &BE         :\ F6C9= 46 BE       F>
ROR &BD         :\ F6CB= 66 BD       f=
LSR &BE         :\ F6CD= 46 BE       F>
ROR &BD         :\ F6CF= 66 BD       f=
LSR &BE         :\ F6D1= 46 BE       F>
ROR &BD         :\ F6D3= 66 BD       f=
LDA &7000       :\ F6D5= AD 00 70    -.p
AND #&F0        :\ F6D8= 29 F0       )p
CMP #&A0        :\ F6DA= C9 A0       I 
BCS LF6EA       :\ F6DC= B0 0C       0.
CMP #&00        :\ F6DE= C9 00       I.
BNE LF6E6       :\ F6E0= D0 04       P.
.LF6E2
LSR &BE         :\ F6E2= 46 BE       F>
ROR &BD         :\ F6E4= 66 BD       f=
.LF6E6
LSR &BE         :\ F6E6= 46 BE       F>
ROR &BD         :\ F6E8= 66 BD       f=
.LF6EA
LDA &032C       :\ F6EA= AD 2C 03    -,.
BPL LF6F4       :\ F6ED= 10 05       ..
LDX #&0A        :\ F6EF= A2 0A       ".
JSR LF70C       :\ F6F1= 20 0C F7     .w
.LF6F4
JSR LF1FE       :\ F6F4= 20 FE F1     ~q
JMP LF578       :\ F6F7= 4C 78 F5    Lxu
 
.LF6FA
SEC             :\ F6FA= 38          8
LDA #&00        :\ F6FB= A9 00       ).
SBC &0306,X     :\ F6FD= FD 06 03    }..
STA &0306,X     :\ F700= 9D 06 03    ...
LDA #&00        :\ F703= A9 00       ).
SBC &0305,X     :\ F705= FD 05 03    }..
STA &0305,X     :\ F708= 9D 05 03    ...
RTS             :\ F70B= 60          `
 
.LF70C
SEC             :\ F70C= 38          8
LDA #&00        :\ F70D= A9 00       ).
SBC &B3,X       :\ F70F= F5 B3       u3
STA &B3,X       :\ F711= 95 B3       .3
LDA #&00        :\ F713= A9 00       ).
SBC &B4,X       :\ F715= F5 B4       u4
STA &B4,X       :\ F717= 95 B4       .4
RTS             :\ F719= 60          `


\ OSFILE HANDLER
\ ==============
.LF71A
STA &9E         :\ F71A= 85 9E       ..
STX &9F         :\ F71C= 86 9F       ..
STY &A0         :\ F71E= 84 A0       . 
LDX #&A9        :\ F720= A2 A9       ")
LDY #&03        :\ F722= A0 03        .
.LF724
LDA (&9F),Y     :\ F724= B1 9F       1.
STA &00A9,Y     :\ F726= 99 A9 00    .).
DEY             :\ F729= 88          .
BPL LF724       :\ F72A= 10 F8       .x
LDA &9E         :\ F72C= A5 9E       %.
BEQ LF74A       :\ F72E= F0 1A       p.
LDA #&00        :\ F730= A9 00       ).
STA &AD         :\ F732= 85 AD       .-
LDY #&06        :\ F734= A0 06        .
LDA (&9F),Y     :\ F736= B1 9F       1.
BEQ LF740       :\ F738= F0 06       p.
JSR LF945       :\ F73A= 20 45 F9     Ey
JMP LF76E       :\ F73D= 4C 6E F7    Lnw
 
.LF740
LDA #&FF        :\ F740= A9 FF       ).
STA &AD         :\ F742= 85 AD       .-
JSR LF945       :\ F744= 20 45 F9     Ey
JMP LF76E       :\ F747= 4C 6E F7    Lnw
 
.LF74A
LDY #&06        :\ F74A= A0 06        .
LDA (&9F),Y     :\ F74C= B1 9F       1.
STA &AD         :\ F74E= 85 AD       .-
INY             :\ F750= C8          H
LDA (&9F),Y     :\ F751= B1 9F       1.
STA &AE         :\ F753= 85 AE       ..
LDY #&0A        :\ F755= A0 0A        .
LDA (&9F),Y     :\ F757= B1 9F       1.
STA &AF         :\ F759= 85 AF       ./
INY             :\ F75B= C8          H
LDA (&9F),Y     :\ F75C= B1 9F       1.
STA &B0         :\ F75E= 85 B0       .0
LDY #&0E        :\ F760= A0 0E        .
LDA (&9F),Y     :\ F762= B1 9F       1.
STA &B1         :\ F764= 85 B1       .1
INY             :\ F766= C8          H
LDA (&9F),Y     :\ F767= B1 9F       1.
STA &B2         :\ F769= 85 B2       .2
JSR LFAB8       :\ F76B= 20 B8 FA     8z
.LF76E
LDA &9E         :\ F76E= A5 9E       %.
LDX &9F         :\ F770= A6 9F       &.
LDY &A0         :\ F772= A4 A0       $ 
RTS             :\ F774= 60          `


\ CLI HANDLER
\ =========== 
.LF775
STA &9B
STX &9C:STY &9D         :\ &9C/D=>command line
LDY #&01                :\ Point to second character
:                       :\ *BUG* This means OSCLI "fred" parses "red"
.LF77D
LDA (&9C),Y:STA &00FF,Y :\ Copy command line to &100+
INY:CMP #&0D:BNE LF77D  :\ Loop until <cr>
JSR LF8C3               :\ Process command line
LDY &9D:LDX &9C:LDA &9B :\ Restore X/Y/A (not needed)
RTS


\ VDU 31,x,y - TAB
\ ================ 
.LF791
LDX &0307       :\ F791= AE 07 03    ...
CPX #&20        :\ F794= E0 20       ` 
BCS LF7B6       :\ F796= B0 1E       0.
LDA &0306       :\ F798= AD 06 03    -..
CMP #&10        :\ F79B= C9 10       I.
BCS LF7B6       :\ F79D= B0 17       0.
LDY &E0         :\ F79F= A4 E0       $`
JSR LFD1D       :\ F7A1= 20 1D FD     .}
STX &E0         :\ F7A4= 86 E0       .`
LSR &DF         :\ F7A6= 46 DF       F_
ASL A           :\ F7A8= 0A          .
ASL A           :\ F7A9= 0A          .
ASL A           :\ F7AA= 0A          .
ASL A           :\ F7AB= 0A          .
ASL A           :\ F7AC= 0A          .
STA &DE         :\ F7AD= 85 DE       .^
ROL &DF         :\ F7AF= 26 DF       &_
LDY &E0         :\ F7B1= A4 E0       $`
JSR LFD1D       :\ F7B3= 20 1D FD     .}
.LF7B6
JMP LF578       :\ F7B6= 4C 78 F5    Lxu

.LF7B9 
EQUS " WORK +"


\ PRINT INLINE TEXT
\ =================
.LF7C0
PLA:STA &E8:PLA:STA &E9    :\ &E8/9=>inline text
.LF7C6
LDY #&00
INC &E8:BNE LF7CE:INC &E9  :\ Update address
.LF7CE
LDA (&E8),Y:BMI LF7D8      :\ b7=1, end of text
JSR OSWRCH:JMP LF7C6       :\ Print character and loop for more
.LF7D8
JMP (&00E8)                :\ Jump back to code after text


.LF7DB
LDX #&D4        :\ F7DB= A2 D4       "T
JSR LF7E0       :\ F7DD= 20 E0 F7     `w
.LF7E0
LDA &01,X       :\ F7E0= B5 01       5.
JSR LF7F1       :\ F7E2= 20 F1 F7     qw
INX             :\ F7E5= E8          h
INX             :\ F7E6= E8          h
LDA &FE,X       :\ F7E7= B5 FE       5~
JSR LF7F1       :\ F7E9= 20 F1 F7     qw
.LF7EC
LDA #&20        :\ F7EC= A9 20       ) 
JMP OSWRCH      :\ F7EE= 4C EE FF    Ln.
 
.LF7F1
PHA             :\ F7F1= 48          H
LSR A           :\ F7F2= 4A          J
LSR A           :\ F7F3= 4A          J
LSR A           :\ F7F4= 4A          J
LSR A           :\ F7F5= 4A          J
JSR LF7FA       :\ F7F6= 20 FA F7     zw
PLA             :\ F7F9= 68          h
.LF7FA
AND #&0F        :\ F7FA= 29 0F       ).
CMP #&0A        :\ F7FC= C9 0A       I.
BCC LF802       :\ F7FE= 90 02       ..
ADC #&06        :\ F800= 69 06       i.
.LF802
ADC #&30        :\ F802= 69 30       i0
JMP OSWRCH      :\ F804= 4C EE FF    Ln.
 
.LF807
JSR LF863       :\ F807= 20 63 F8     cx
LDX #&00        :\ F80A= A2 00       ".
CMP #&22        :\ F80C= C9 22       I"
BEQ LF816       :\ F80E= F0 06       p.
INX             :\ F810= E8          h
BNE LF82E       :\ F811= D0 1B       P.
.LF813
JMP LFA53       :\ F813= 4C 53 FA    LSz
 
.LF816
INY             :\ F816= C8          H
LDA &0100,Y     :\ F817= B9 00 01    9..
CMP #&0D        :\ F81A= C9 0D       I.
BEQ LF813       :\ F81C= F0 F5       pu
STA &0140,X     :\ F81E= 9D 40 01    .@.
INX             :\ F821= E8          h
CMP #&22        :\ F822= C9 22       I"
BNE LF816       :\ F824= D0 F0       Pp
INY             :\ F826= C8          H
LDA &0100,Y     :\ F827= B9 00 01    9..
CMP #&22        :\ F82A= C9 22       I"
BEQ LF816       :\ F82C= F0 E8       ph
.LF82E
LDA #&0D        :\ F82E= A9 0D       ).
STA &013F,X     :\ F830= 9D 3F 01    .?.
LDA #&40        :\ F833= A9 40       )@
STA &C9         :\ F835= 85 C9       .I
LDA #&01        :\ F837= A9 01       ).
STA &CA         :\ F839= 85 CA       .J
LDX #&C9        :\ F83B= A2 C9       "I
RTS             :\ F83D= 60          `
 
.LF83E
LDY #&00        :\ F83E= A0 00        .
.LF840
LDA &00,X       :\ F840= B5 00       5.
STA &00C9,Y     :\ F842= 99 C9 00    .I.
INX             :\ F845= E8          h
INY             :\ F846= C8          H
CPY #&0A        :\ F847= C0 0A       @.
BCC LF840       :\ F849= 90 F5       .u
LDY #&FF        :\ F84B= A0 FF        .
LDA #&0D        :\ F84D= A9 0D       ).
.LF84F
INY             :\ F84F= C8          H
CPY #&0E        :\ F850= C0 0E       @.
BCS LF85B       :\ F852= B0 07       0.
CMP (&C9),Y     :\ F854= D1 C9       QI
BNE LF84F       :\ F856= D0 F7       Pw
CPY #&00        :\ F858= C0 00       @.
RTS             :\ F85A= 60          `
 
.LF85B
BRK:EQUB 254:EQUS "NAME":BRK
\ *BUG* Error number wrong, should be 221

.LF862
INY             :\ F862= C8          H
.LF863
LDA &0100,Y     :\ F863= B9 00 01    9..
CMP #&20        :\ F866= C9 20       I 
BEQ LF862       :\ F868= F0 F8       px
RTS             :\ F86A= 60          `
 
.LF86B
CMP #&30:BCC LF87E
CMP #&3A:BCC LF87B
SBC #&07:BCC LF87E
CMP #&40:BCS LF87D
.LF87B
AND #&0F
.LF87D
RTS
 
.LF87E
SEC             :\ F87E= 38          8
RTS             :\ F87F= 60          `
 
.LF880
LDA #&00        :\ F880= A9 00       ).
STA &00,X       :\ F882= 95 00       ..
STA &01,X       :\ F884= 95 01       ..
STA &02,X       :\ F886= 95 02       ..
JSR LF863       :\ F888= 20 63 F8     cx
.LF88B
LDA &0100,Y     :\ F88B= B9 00 01    9..
JSR LF86B       :\ F88E= 20 6B F8     kx
BCS LF8A8       :\ F891= B0 15       0.
ASL A           :\ F893= 0A          .
ASL A           :\ F894= 0A          .
ASL A           :\ F895= 0A          .
ASL A           :\ F896= 0A          .
STY &02,X       :\ F897= 94 02       ..
LDY #&04        :\ F899= A0 04        .
.LF89B
ASL A           :\ F89B= 0A          .
ROL &00,X       :\ F89C= 36 00       6.
ROL &01,X       :\ F89E= 36 01       6.
DEY             :\ F8A0= 88          .
BNE LF89B       :\ F8A1= D0 F8       Px
LDY &02,X       :\ F8A3= B4 02       4.
INY             :\ F8A5= C8          H
BNE LF88B       :\ F8A6= D0 E3       Pc
.LF8A8
LDA &02,X       :\ F8A8= B5 02       5.
RTS             :\ F8AA= 60          `

\ Command table
\ -------------
.LF8AB
EQUS "CAT" :EQUB LFA00 DIV 256:EQUB LFA00 AND 255
EQUS "LOAD":EQUB LF932 DIV 256:EQUB LF932 AND 255
EQUS "SAVE":EQUB LFA91 DIV 256:EQUB LFA91 AND 255
EQUS "RUN" :EQUB LF9F6 DIV 256:EQUB LF9F6 AND 255
EQUS ""    :EQUB LF8FA DIV 256:EQUB LF8FA AND 255

\ Process command line at &100+
\ -----------------------------
.LF8C3
LDX #&FF        :\ F8C3= A2 FF       ".
CLD             :\ F8C5= D8          X
.LF8C6
LDY #&00        :\ F8C6= A0 00        .
STY &DD         :\ F8C8= 84 DD       .]
JSR LF863       :\ F8CA= 20 63 F8     cx
DEY             :\ F8CD= 88          .
.LF8CE
INY             :\ F8CE= C8          H
INX             :\ F8CF= E8          h
.LF8D0
LDA LF8AB,X     :\ F8D0= BD AB F8    =+x
BMI LF8ED       :\ F8D3= 30 18       0.
CMP &0100,Y     :\ F8D5= D9 00 01    Y..
BEQ LF8CE       :\ F8D8= F0 F4       pt
DEX             :\ F8DA= CA          J
.LF8DB
INX             :\ F8DB= E8          h
LDA LF8AB,X     :\ F8DC= BD AB F8    =+x
BPL LF8DB       :\ F8DF= 10 FA       .z
INX             :\ F8E1= E8          h
LDA &0100,Y     :\ F8E2= B9 00 01    9..
CMP #&2E        :\ F8E5= C9 2E       I.
BNE LF8C6       :\ F8E7= D0 DD       P]
INY             :\ F8E9= C8          H
DEX             :\ F8EA= CA          J
BCS LF8D0       :\ F8EB= B0 E3       0c
.LF8ED
STA &CA         :\ F8ED= 85 CA       .J
LDA LF8AB+1,X   :\ F8EF= BD AC F8    =,x
STA &C9         :\ F8F2= 85 C9       .I
CLC             :\ F8F4= 18          .
LDX #&00        :\ F8F5= A2 00       ".
JMP (&00C9)     :\ Jump to routine with X=&00, CLC

.LF8FA
BRK:EQUB 254:EQUS "BAD COMMAND":BRK


\ OSARGS HANDLER
\ ==============
.LF908
BRK             :\ **BANG!**

.LF909
JSR LFB61       :\ F909= 20 61 FB     a{
BVC LF908       :\ F90C= 50 FA       Pz
BEQ LF909       :\ F90E= F0 F9       py
JSR LFBFE       :\ F910= 20 FE FB     ~{
LDY #&00        :\ F913= A0 00        .
.LF915
JSR OSBGET      :\ F915= 20 D7 FF     W.
STA (&CB),Y     :\ F918= 91 CB       .K
INC &CB         :\ F91A= E6 CB       fK
BNE LF920       :\ F91C= D0 02       P.
INC &CC         :\ F91E= E6 CC       fL
.LF920
LDX #&D4        :\ F920= A2 D4       "T
JSR LF9DE       :\ F922= 20 DE F9     ^y
BNE LF915       :\ F925= D0 EE       Pn
SEC             :\ F927= 38          8
.LF928
ROR &DD         :\ F928= 66 DD       f]
CLC             :\ F92A= 18          .
ROR &DD         :\ F92B= 66 DD       f]
PLP             :\ F92D= 28          (
RTS             :\ F92E= 60          `
 
\ UNREACHABLE
SEC             :\ F92F= 38          8
ROR &DD         :\ F930= 66 DD       f]


\ *LOAD <name> (<addr>)
\ =====================
.LF932
JSR LF807       :\ F932= 20 07 F8     .x
LDX #&CB        :\ F935= A2 CB       "K
JSR LF880       :\ F937= 20 80 F8     .x
BEQ LF940       :\ F93A= F0 04       p.
LDA #&FF        :\ F93C= A9 FF       ).
STA &CD         :\ F93E= 85 CD       .M
.LF940
JSR LFA4C       :\ F940= 20 4C FA     Lz
LDX #&C9        :\ F943= A2 C9       "I
.LF945
PHP             :\ F945= 08          .
SEI             :\ F946= 78          x
JSR LF83E       :\ F947= 20 3E F8     >x
PHP             :\ F94A= 08          .
JSR LFC13       :\ F94B= 20 13 FC     .|
PLP             :\ F94E= 28          (
BEQ LF909       :\ F94F= F0 B8       p8
LDA #&00        :\ F951= A9 00       ).
STA &D0         :\ F953= 85 D0       .P
STA &D1         :\ F955= 85 D1       .Q
.LF957
JSR LF979       :\ F957= 20 79 F9     yy
BCC LF928       :\ F95A= 90 CC       .L
INC &D0         :\ F95C= E6 D0       fP
INC &CC         :\ F95E= E6 CC       fL
BNE LF957       :\ F960= D0 F5       Pu
CLC             :\ F962= 18          .
BCC LF928       :\ F963= 90 C3       .C
.LF965
JSR OSWRCH      :\ F965= 20 EE FF     n.
INY             :\ F968= C8          H
.LF969
LDA &00ED,Y     :\ F969= B9 ED 00    9m.
CMP #&0D        :\ F96C= C9 0D       I.
BNE LF965       :\ F96E= D0 F5       Pu
.LF970
INY             :\ F970= C8          H
JSR LF7EC       :\ F971= 20 EC F7     lw
CPY #&0E        :\ F974= C0 0E       @.
BCC LF970       :\ F976= 90 F8       .x
RTS             :\ F978= 60          `
 
.LF979
LDA #&00        :\ F979= A9 00       ).
STA &DC         :\ F97B= 85 DC       .\
JSR LFB61       :\ F97D= 20 61 FB     a{
BVC LF979+1     :\ **BANG!**
BNE LF979       :\ F982= D0 F5       Pu
JSR LFB9C       :\ F984= 20 9C FB     .{
PHP             :\ F987= 08          .
JSR LFBB5       :\ F988= 20 B5 FB     5{
PLP             :\ F98B= 28          (
BEQ LF99E       :\ F98C= F0 10       p.
LDA &DB         :\ F98E= A5 DB       %[
AND #&20        :\ F990= 29 20       ) 
ORA &EA         :\ F992= 05 EA       .j
BNE LF979       :\ F994= D0 E3       Pc
JSR LF969       :\ F996= 20 69 F9     iy
JSR OSNEWL      :\ F999= 20 E7 FF     g.
BNE LF979       :\ F99C= D0 DB       P[
.LF99E
LDX #&02        :\ F99E= A2 02       ".
LDA &DD         :\ F9A0= A5 DD       %]
BMI LF9B7       :\ F9A2= 30 13       0.
.LF9A4
LDA &CF,X       :\ F9A4= B5 CF       5O
CMP &D8,X       :\ F9A6= D5 D8       UX
BCS LF9B2       :\ F9A8= B0 08       0.
LDA #&05        :\ F9AA= A9 05       ).
JSR LFC15       :\ F9AC= 20 15 FC     .|
JSR LFC13       :\ F9AF= 20 13 FC     .|
.LF9B2
BNE LF979       :\ F9B2= D0 C5       PE
DEX             :\ F9B4= CA          J
BNE LF9A4       :\ F9B5= D0 ED       Pm
.LF9B7
JSR LFBFE       :\ F9B7= 20 FE FB     ~{
BIT &DB         :\ F9BA= 24 DB       $[
BVC LF9C9       :\ F9BC= 50 0B       P.
DEY             :\ F9BE= 88          .
.LF9BF
INY             :\ F9BF= C8          H
JSR OSBGET      :\ F9C0= 20 D7 FF     W.
STA (&CB),Y     :\ F9C3= 91 CB       .K
CPY &D8         :\ F9C5= C4 D8       DX
BNE LF9BF       :\ F9C7= D0 F6       Pv
.LF9C9
LDA &DC         :\ F9C9= A5 DC       %\
STA &CE         :\ F9CB= 85 CE       .N
JSR OSBGET      :\ F9CD= 20 D7 FF     W.
CMP &CE         :\ F9D0= C5 CE       EN
BEQ LF9DB       :\ F9D2= F0 07       p.
BRK:EQUB 254:EQUS "SUM?":BRK
\ *BUG* Error number wrong, should be 216

.LF9DB
ROL &DB         :\ F9DB= 26 DB       &[
RTS             :\ F9DD= 60          `
 
.LF9DE
INC &00,X       :\ F9DE= F6 00       v.
BNE LF9E4       :\ F9E0= D0 02       P.
INC &01,X       :\ F9E2= F6 01       v.
.LF9E4
LDA &00,X       :\ F9E4= B5 00       5.
CMP &02,X       :\ F9E6= D5 02       U.
BNE LF9EE       :\ F9E8= D0 04       P.
LDA &01,X       :\ F9EA= B5 01       5.
CMP &03,X       :\ F9EC= D5 03       U.
.LF9EE
RTS             :\ F9EE= 60          `

\ UNREACHABLE

DEX             :\ F9EF= CA          J
JSR LFA4C       :\ F9F0= 20 4C FA     Lz
STX &EA         :\ F9F3= 86 EA       .j
.LF9F5
RTS             :\ F9F5= 60          `
 
.LF9F6
JSR LF932       :\ F9F6= 20 32 F9     2y
BIT &DD         :\ F9F9= 24 DD       $]
BVS LFA49       :\ F9FB= 70 4C       pL
JMP (&00D6)     :\ F9FD= 6C D6 00    lV.


\ *CAT
\ ====
.LFA00
PHP             :\ FA00= 08          .
JSR LFA4C       :\ FA01= 20 4C FA     Lz
JSR LFC13       :\ FA04= 20 13 FC     .|
.LFA07
JSR LFB61       :\ FA07= 20 61 FB     a{
BVS LFA0E       :\ FA0A= 70 02       p.
PLP             :\ FA0C= 28          (
RTS             :\ FA0D= 60          `
 
.LFA0E
BEQ LFA1A       :\ FA0E= F0 0A       p.
LDY #&00        :\ FA10= A0 00        .
JSR LF970       :\ FA12= 20 70 F9     py
JSR LF7DB       :\ FA15= 20 DB F7     [w
BNE LFA33       :\ FA18= D0 19       P.
.LFA1A
JSR LFB9C       :\ FA1A= 20 9C FB     .{
JSR LFBB5       :\ FA1D= 20 B5 FB     5{
JSR LF969       :\ FA20= 20 69 F9     iy
JSR LF7DB       :\ FA23= 20 DB F7     [w
ROL &DB         :\ FA26= 26 DB       &[
BPL LFA33       :\ FA28= 10 09       ..
INX             :\ FA2A= E8          h
JSR LF7E0       :\ FA2B= 20 E0 F7     `w
LDA &FD,X       :\ FA2E= B5 FD       5}
JSR LF7F1       :\ FA30= 20 F1 F7     qw
.LFA33
JSR OSNEWL      :\ FA33= 20 E7 FF     g.
BNE LFA07       :\ FA36= D0 CF       PO
JMP OSNEWL      :\ FA38= 4C E7 FF    Lg.
 
.LFA3B
JSR LF880       :\ FA3B= 20 80 F8     .x
BEQ LFA53       :\ FA3E= F0 13       p.
RTS             :\ FA40= 60          `
 
LDX #&CB        :\ FA41= A2 CB       "K
JSR LFA3B       :\ FA43= 20 3B FA     ;z
JSR LFA4C       :\ FA46= 20 4C FA     Lz
.LFA49
JMP (&00CB)     :\ FA49= 6C CB 00    lK.
 
.LFA4C
JSR LF863       :\ FA4C= 20 63 F8     cx
CMP #&0D        :\ FA4F= C9 0D       I.
BEQ LF9F5       :\ FA51= F0 A2       p"
.LFA53
BRK:EQUB 254:EQUS "SYNTAX":BRK
\ *BUG* error number wrong, should be 220

.LFA5C
SEC             :\ FA5C= 38          8
LDA &D1         :\ FA5D= A5 D1       %Q
SBC &CF         :\ FA5F= E5 CF       eO
PHA             :\ FA61= 48          H
LDA &D2         :\ FA62= A5 D2       %R
SBC &D0         :\ FA64= E5 D0       eP
TAY             :\ FA66= A8          (
PLA             :\ FA67= 68          h
CLC             :\ FA68= 18          .
ADC &CB         :\ FA69= 65 CB       eK
STA &CD         :\ FA6B= 85 CD       .M
TYA             :\ FA6D= 98          .
ADC &CC         :\ FA6E= 65 CC       eL
STA &CE         :\ FA70= 85 CE       .N
LDY #&04        :\ FA72= A0 04        .
.LFA74
LDA &00CA,Y     :\ FA74= B9 CA 00    9J.
JSR OSBPUT      :\ FA77= 20 D4 FF     T.
DEY             :\ FA7A= 88          .
BNE LFA74       :\ FA7B= D0 F7       Pw
.LFA7D
LDA (&CF),Y     :\ FA7D= B1 CF       1O
JSR OSBPUT      :\ FA7F= 20 D4 FF     T.
INC &CF         :\ FA82= E6 CF       fO
BNE LFA88       :\ FA84= D0 02       P.
INC &D0         :\ FA86= E6 D0       fP
.LFA88
LDX #&CB        :\ FA88= A2 CB       "K
JSR LF9DE       :\ FA8A= 20 DE F9     ^y
BNE LFA7D       :\ FA8D= D0 EE       Pn
PLP             :\ FA8F= 28          (
RTS             :\ FA90= 60          `

.LFA91 
JSR LF807       :\ FA91= 20 07 F8     .x
LDX #&CB        :\ FA94= A2 CB       "K
JSR LFA3B       :\ FA96= 20 3B FA     ;z
LDX #&D1        :\ FA99= A2 D1       "Q
JSR LFA3B       :\ FA9B= 20 3B FA     ;z
LDX #&CD        :\ FA9E= A2 CD       "M
JSR LF880       :\ FAA0= 20 80 F8     .x
PHP             :\ FAA3= 08          .
LDA &CB         :\ FAA4= A5 CB       %K
LDX &CC         :\ FAA6= A6 CC       &L
PLP             :\ FAA8= 28          (
BNE LFAAF       :\ FAA9= D0 04       P.
STA &CD         :\ FAAB= 85 CD       .M
STX &CE         :\ FAAD= 86 CE       .N
.LFAAF
STA &CF         :\ FAAF= 85 CF       .O
STX &D0         :\ FAB1= 86 D0       .P
JSR LFA4C       :\ FAB3= 20 4C FA     Lz
LDX #&C9        :\ FAB6= A2 C9       "I
.LFAB8
PHP             :\ FAB8= 08          .
SEI             :\ FAB9= 78          x
JSR LF83E       :\ FABA= 20 3E F8     >x
PHP             :\ FABD= 08          .
LDA #&06        :\ FABE= A9 06       ).
JSR LFC15       :\ FAC0= 20 15 FC     .|
LDX #&07        :\ FAC3= A2 07       ".
JSR LFB4D       :\ FAC5= 20 4D FB     M{
PLP             :\ FAC8= 28          (
BEQ LFA5C       :\ FAC9= F0 91       p.
LDX #&04        :\ FACB= A2 04       ".
.LFACD
LDA &CE,X       :\ FACD= B5 CE       5N
STA &D2,X       :\ FACF= 95 D2       .R
DEX             :\ FAD1= CA          J
BNE LFACD       :\ FAD2= D0 F9       Py
STX &D0         :\ FAD4= 86 D0       .P
STX &D1         :\ FAD6= 86 D1       .Q
LDA &D5         :\ FAD8= A5 D5       %U
BNE LFADE       :\ FADA= D0 02       P.
DEC &D6         :\ FADC= C6 D6       FV
.LFADE
DEC &D5         :\ FADE= C6 D5       FU
CLC             :\ FAE0= 18          .
.LFAE1
ROR &D2         :\ FAE1= 66 D2       fR
SEC             :\ FAE3= 38          8
LDX #&FF        :\ FAE4= A2 FF       ".
LDA &D5         :\ FAE6= A5 D5       %U
SBC &D3         :\ FAE8= E5 D3       eS
STA &CF         :\ FAEA= 85 CF       .O
LDA &D6         :\ FAEC= A5 D6       %V
SBC &D4         :\ FAEE= E5 D4       eT
PHP             :\ FAF0= 08          .
ROR &D2         :\ FAF1= 66 D2       fR
PLP             :\ FAF3= 28          (
BCC LFAFC       :\ FAF4= 90 06       ..
CLC             :\ FAF6= 18          .
BEQ LFAFC       :\ FAF7= F0 03       p.
STX &CF         :\ FAF9= 86 CF       .O
SEC             :\ FAFB= 38          8
.LFAFC
ROR &D2         :\ FAFC= 66 D2       fR
INX             :\ FAFE= E8          h
JSR LFB0E       :\ FAFF= 20 0E FB     .{
INC &D0         :\ FB02= E6 D0       fP
INC &D4         :\ FB04= E6 D4       fT
INC &CC         :\ FB06= E6 CC       fL
ROL &D2         :\ FB08= 26 D2       &R
BCS LFAE1       :\ FB0A= B0 D5       0U
PLP             :\ FB0C= 28          (
RTS             :\ FB0D= 60          `
 
.LFB0E
LDX #&07        :\ FB0E= A2 07       ".
JSR LFB4D       :\ FB10= 20 4D FB     M{
STX &DC         :\ FB13= 86 DC       .\
LDY #&04        :\ FB15= A0 04        .
.LFB17
LDA #&2A        :\ FB17= A9 2A       )*
JSR OSBPUT      :\ FB19= 20 D4 FF     T.
DEY             :\ FB1C= 88          .
BNE LFB17       :\ FB1D= D0 F8       Px
.LFB1F
LDA (&C9),Y     :\ FB1F= B1 C9       1I
JSR OSBPUT      :\ FB21= 20 D4 FF     T.
INY             :\ FB24= C8          H
CMP #&0D        :\ FB25= C9 0D       I.
BNE LFB1F       :\ FB27= D0 F6       Pv
LDY #&08        :\ FB29= A0 08        .
.LFB2B
LDA &00CA,Y     :\ FB2B= B9 CA 00    9J.
JSR OSBPUT      :\ FB2E= 20 D4 FF     T.
DEY             :\ FB31= 88          .
BNE LFB2B       :\ FB32= D0 F7       Pw
JSR LFB54       :\ FB34= 20 54 FB     T{
BIT &D2         :\ FB37= 24 D2       $R
BVC LFB46       :\ FB39= 50 0B       P.
DEY             :\ FB3B= 88          .
.LFB3C
INY             :\ FB3C= C8          H
LDA (&D3),Y     :\ FB3D= B1 D3       1S
JSR OSBPUT      :\ FB3F= 20 D4 FF     T.
CPY &CF         :\ FB42= C4 CF       DO
BNE LFB3C       :\ FB44= D0 F6       Pv
.LFB46
LDA &DC         :\ FB46= A5 DC       %\
JSR OSBPUT      :\ FB48= 20 D4 FF     T.
LDX #&04        :\ FB4B= A2 04       ".
.LFB4D
STX &7002       :\ FB4D= 8E 02 70    ..p
LDX #&78        :\ FB50= A2 78       "x
BNE LFB56       :\ FB52= D0 02       P.
.LFB54
LDX #&1E        :\ FB54= A2 1E       ".
.LFB56
JSR LFE3F       :\ FB56= 20 3F FE     ?~
DEX             :\ FB59= CA          J
BNE LFB56       :\ FB5A= D0 FA       Pz
RTS             :\ FB5C= 60          `
 
.LFB5D
LDX #&06        :\ FB5D= A2 06       ".
BNE LFB56       :\ FB5F= D0 F5       Pu
.LFB61
BIT &7001       :\ FB61= 2C 01 70    ,.p
BPL LFB61       :\ FB64= 10 FB       .{
BVC LFB61       :\ FB66= 50 F9       Py
.LFB68
LDY #&00        :\ FB68= A0 00        .
STA &C3         :\ FB6A= 85 C3       .C
LDA #&10        :\ FB6C= A9 10       ).
STA &C2         :\ FB6E= 85 C2       .B
.LFB70
BIT &7001       :\ FB70= 2C 01 70    ,.p
BPL LFB84       :\ FB73= 10 0F       ..
BVC LFB84       :\ FB75= 50 0D       P.
JSR LFC92       :\ FB77= 20 92 FC     .|
BCS LFB68       :\ FB7A= B0 EC       0l
DEC &C3         :\ FB7C= C6 C3       FC
BNE LFB70       :\ FB7E= D0 F0       Pp
DEC &C2         :\ FB80= C6 C2       FB
BNE LFB70       :\ FB82= D0 EC       Pl
.LFB84
BVS LFB87       :\ FB84= 70 01       p.
RTS             :\ FB86= 60          `
 
.LFB87
LDY #&04        :\ FB87= A0 04        .
PHP             :\ FB89= 08          .
JSR LFBB7       :\ FB8A= 20 B7 FB     7{
PLP             :\ FB8D= 28          (
LDY #&04        :\ FB8E= A0 04        .
LDA #&2A        :\ FB90= A9 2A       )*
.LFB92
CMP &00D3,Y     :\ FB92= D9 D3 00    YS.
BNE LFB9A       :\ FB95= D0 03       P.
DEY             :\ FB97= 88          .
BNE LFB92       :\ FB98= D0 F8       Px
.LFB9A
RTS             :\ FB9A= 60          `
 
.LFB9B
INY             :\ FB9B= C8          H
.LFB9C
JSR OSBGET      :\ FB9C= 20 D7 FF     W.
STA &00ED,Y     :\ FB9F= 99 ED 00    .m.
CMP #&0D        :\ FBA2= C9 0D       I.
BNE LFB9B       :\ FBA4= D0 F5       Pu
LDY #&FF        :\ FBA6= A0 FF        .
.LFBA8
INY             :\ FBA8= C8          H
LDA (&C9),Y     :\ FBA9= B1 C9       1I
CMP &00ED,Y     :\ FBAB= D9 ED 00    Ym.
BNE LFB9A       :\ FBAE= D0 EA       Pj
CMP #&0D        :\ FBB0= C9 0D       I.
BNE LFBA8       :\ FBB2= D0 F4       Pt
RTS             :\ FBB4= 60          `
 
.LFBB5
LDY #&08        :\ FBB5= A0 08        .
.LFBB7
JSR OSBGET      :\ FBB7= 20 D7 FF     W.
STA &00D3,Y     :\ FBBA= 99 D3 00    .S.
DEY             :\ FBBD= 88          .
BNE LFBB7       :\ FBBE= D0 F7       Pw
RTS             :\ FBC0= 60          `


\ OSBGET HANDLER
\ ============== 
.LFBC1
STX &EC         :\ FBC1= 86 EC       .l
STY &C3         :\ FBC3= 84 C3       .C
PHP             :\ FBC5= 08          .
SEI             :\ FBC6= 78          x
.LFBC7
LDA #&78        :\ FBC7= A9 78       )x
STA &C0         :\ FBC9= 85 C0       .@
.LFBCB
JSR LFC92       :\ FBCB= 20 92 FC     .|
BCC LFBC7       :\ FBCE= 90 F7       .w
INC &C0         :\ FBD0= E6 C0       f@
BPL LFBCB       :\ FBD2= 10 F7       .w
.LFBD4
LDA #&53        :\ FBD4= A9 53       )S
STA &C4         :\ FBD6= 85 C4       .D
LDX #&00        :\ FBD8= A2 00       ".
LDY &7002       :\ FBDA= AC 02 70    ,.p
.LFBDD
JSR LFCA2       :\ FBDD= 20 A2 FC     "|
BEQ LFBE2       :\ FBE0= F0 00       p.
.LFBE2
BEQ LFBE5       :\ FBE2= F0 01       p.
INX             :\ FBE4= E8          h
.LFBE5
DEC &C4         :\ FBE5= C6 C4       FD
BNE LFBDD       :\ FBE7= D0 F4       Pt
CPX #&0C        :\ FBE9= E0 0C       `.
ROR &C0         :\ FBEB= 66 C0       f@
BCC LFBD4       :\ FBED= 90 E5       .e
LDA &C0         :\ FBEF= A5 C0       %@
PLP             :\ FBF1= 28          (
LDY &C3         :\ FBF2= A4 C3       $C
LDX &EC         :\ FBF4= A6 EC       &l
.LFBF6
PHA             :\ FBF6= 48          H
CLC             :\ FBF7= 18          .
ADC &DC         :\ FBF8= 65 DC       e\
STA &DC         :\ FBFA= 85 DC       .\
PLA             :\ FBFC= 68          h
RTS             :\ FBFD= 60          `
 
.LFBFE
LDA &CD         :\ FBFE= A5 CD       %M
BMI LFC0A       :\ FC00= 30 08       0.
LDA &D4         :\ FC02= A5 D4       %T
STA &CB         :\ FC04= 85 CB       .K
LDA &D5         :\ FC06= A5 D5       %U
STA &CC         :\ FC08= 85 CC       .L
.LFC0A
RTS             :\ FC0A= 60          `
 

\ OSFIND HANDLER
\ ==============
.LFC0B
CMP #&C0:BEQ LFC13       :\ Jump with OPENUP
LDA #&06:BNE LFC15       :\ A=&06 for OPENIN/OPENOUT/CLOSE
.LFC13
LDA #&04                 :\ A=&04 for OPENUP
.LFC15
LDX #&07:STX &7002
BIT &EA:BNE LFC4B
CMP #&05:BEQ LFC38:BCS LFC2D
JSR LF7C0
EQUS "PLAY"
BNE LFC42

.LFC2D
JSR LF7C0:EQUS "RECORD"
BNE LFC42
.LFC38
JSR LF7C0:EQUS "REWIND"
NOP
.LFC42
JSR LF7C0:EQUS " TAPE"
NOP      
.LFC4B
JSR OSRDCH
JMP OSNEWL
 

\ OSBPUT HANDLER
\ ==============
.LFC51
STX &EC         :\ FC51= 86 EC       .l
STY &C3         :\ FC53= 84 C3       .C
PHP             :\ FC55= 08          .
SEI             :\ FC56= 78          x
PHA             :\ FC57= 48          H
JSR LFBF6       :\ FC58= 20 F6 FB     v{
STA &C0         :\ FC5B= 85 C0       .@
JSR LFCAD       :\ FC5D= 20 AD FC     -|
LDA #&0A        :\ FC60= A9 0A       ).
STA &C1         :\ FC62= 85 C1       .A
CLC             :\ FC64= 18          .
.LFC65
BCC LFC71       :\ FC65= 90 0A       ..
LDX #&07        :\ FC67= A2 07       ".
STX &7002       :\ FC69= 8E 02 70    ..p
JSR LFCAF       :\ FC6C= 20 AF FC     /|
BMI LFC84       :\ FC6F= 30 13       0.
.LFC71
LDY #&04        :\ FC71= A0 04        .
.LFC73
LDA #&04        :\ FC73= A9 04       ).
.LFC75
STA &7002       :\ FC75= 8D 02 70    ..p
JSR LFCAD       :\ FC78= 20 AD FC     -|
INC &7002       :\ FC7B= EE 02 70    n.p
JSR LFCAD       :\ FC7E= 20 AD FC     -|
DEY             :\ FC81= 88          .
BNE LFC73       :\ FC82= D0 EF       Po
.LFC84
SEC             :\ FC84= 38          8
ROR &C0         :\ FC85= 66 C0       f@
DEC &C1         :\ FC87= C6 C1       FA
BNE LFC65       :\ FC89= D0 DA       PZ
LDY &C3         :\ FC8B= A4 C3       $C
LDX &EC         :\ FC8D= A6 EC       &l
.LFC8F
PLA             :\ FC8F= 68          h
PLP             :\ FC90= 28          (
RTS             :\ FC91= 60          `
 
.LFC92
LDX #&00        :\ FC92= A2 00       ".
LDY &7002       :\ FC94= AC 02 70    ,.p
.LFC97
INX             :\ FC97= E8          h
BEQ LFCA1       :\ FC98= F0 07       p.
JSR LFCA2       :\ FC9A= 20 A2 FC     "|
BEQ LFC97       :\ FC9D= F0 F8       px
CPX #&08        :\ FC9F= E0 08       `.
.LFCA1
RTS             :\ FCA1= 60          `
 
.LFCA2
STY &C5         :\ FCA2= 84 C5       .E
LDA &7002       :\ FCA4= AD 02 70    -.p
TAY             :\ FCA7= A8          (
EOR &C5         :\ FCA8= 45 C5       EE
AND #&20        :\ FCAA= 29 20       ) 
RTS             :\ FCAC= 60          `
 
.LFCAD
LDX #&00        :\ FCAD= A2 00       ".
.LFCAF
LDA #&10        :\ FCAF= A9 10       ).
.LFCB1
BIT &7002       :\ FCB1= 2C 02 70    ,.p
BEQ LFCB1       :\ FCB4= F0 FB       p{
.LFCB6
BIT &7002       :\ FCB6= 2C 02 70    ,.p
BNE LFCB6       :\ FCB9= D0 FB       P{
DEX             :\ FCBB= CA          J
BPL LFCB1       :\ FCBC= 10 F3       .s
RTS             :\ FCBE= 60          `
 
.LFCBF
CMP #&06:BEQ LFCE0       :\ <ACK> - enable VDU
CMP #&15:BEQ LFCE6       :\ <NAK> - disable VDU
LDY &E0:BMI LFCEE        :\ VDU is disabled
CMP #&1B:BEQ LFCE0       :\ <ESC> - reset VDU
CMP #&07:BEQ LFCEF       :\ <BEL> - ring bell
JSR LFD1D                :\ Remove cursor
LDX #&0A:JSR LFE9E       :\ Index into WRCH conversion table
BNE LFD02                :\ No match, output printable character
JMP LFE90                :\ Jump to control character routine

.LFCE0
CLC             :\ FCE0= 18          .
LDX #&00        :\ FCE1= A2 00       ".
STX &7000       :\ FCE3= 8E 00 70    ..p
.LFCE6
LDX #&02        :\ FCE6= A2 02       ".
.LFCE8
PHP             :\ FCE8= 08          .
ASL &DE,X       :\ FCE9= 16 DE       .^
PLP             :\ FCEB= 28          (
ROR &DE,X       :\ FCEC= 76 DE       v^
.LFCEE
RTS             :\ FCEE= 60          `
 
.LFCEF
LDA #&05        :\ FCEF= A9 05       ).
TAY             :\ FCF1= A8          (
.LFCF2
STA &7003       :\ FCF2= 8D 03 70    ..p
.LFCF5
DEX             :\ FCF5= CA          J
BNE LFCF5       :\ FCF6= D0 FD       P}
EOR #&01        :\ FCF8= 49 01       I.
INY             :\ FCFA= C8          H
BPL LFCF2       :\ FCFB= 10 F5       .u
RTS             :\ FCFD= 60          `


\ NMI HANDLER
\ =========== 
.LFCFE
PHA:JMP (userv) :\ Hand on to Atom NMIV
 
\ Store character in display RAM
\ ------------------------------
.LFD02
CMP #&20:BCC LFD1D    :\ If <' ',
ADC #&1F              :\ Add &20
BMI LFD0C:EOR #&60    :\ If <&80, toggle b6/b5
.LFD0C
JSR LFE44             :\ Wait for VSync
STA (&DE),Y           :\ Store in video RAM

.LFD11
INY             :\ FD11= C8          H
CPY #&20        :\ FD12= C0 20       @ 
BCC LFD1B       :\ FD14= 90 05       ..
JSR LFDC5       :\ FD16= 20 C5 FD     E}

.LFD19
LDY #&00        :\ FD19= A0 00        .
.LFD1B
STY &E0         :\ FD1B= 84 E0       .`
.LFD1D
PHA             :\ FD1D= 48          H
JSR LFE44       :\ FD1E= 20 44 FE     D~
LDA (&DE),Y     :\ FD21= B1 DE       1^
EOR &E1         :\ FD23= 45 E1       Ea
STA (&DE),Y     :\ FD25= 91 DE       .^
PLA             :\ FD27= 68          h
RTS             :\ FD28= 60          `
 
.LFD29
JSR LFE0E       :\ FD29= 20 0E FE     .~
LDA #&20        :\ FD2C= A9 20       ) 
JSR LFE44       :\ FD2E= 20 44 FE     D~
STA (&DE),Y     :\ FD31= 91 DE       .^
BPL LFD1B       :\ FD33= 10 E6       .f

.LFD35
JSR LFE0E       :\ FD35= 20 0E FE     .~
JMP LFD1B       :\ FD38= 4C 1B FD    L.}

.LFD3B 
JSR LFDC5       :\ FD3B= 20 C5 FD     E}
.LFD3E
LDY &E0         :\ FD3E= A4 E0       $`
BPL LFD1B       :\ FD40= 10 D9       .Y

.LFD42
LDY #&80        :\ FD42= A0 80        .
STY &E1         :\ FD44= 84 E1       .a
LDY #&00        :\ FD46= A0 00        .
STY &7000       :\ FD48= 8C 00 70    ..p
LDA #&20        :\ FD4B= A9 20       ) 
.LFD4D
STA &4000,Y     :\ FD4D= 99 00 40    ..@
STA &4100,Y     :\ FD50= 99 00 41    ..A
INY             :\ FD53= C8          H
BNE LFD4D       :\ FD54= D0 F7       Pw

.LFD56
LDA #&40        :\ FD56= A9 40       )@
LDY #&00        :\ FD58= A0 00        .
STA &DF         :\ FD5A= 85 DF       ._
STY &DE         :\ FD5C= 84 DE       .^
BEQ LFD1B       :\ FD5E= F0 BB       p;

.LFD60
JSR LFE13       :\ FD60= 20 13 FE     .~
JMP LFD1B       :\ FD63= 4C 1B FD    L.}

.LFD66 
CLC             :\ FD66= 18          .
LDA #&10        :\ FD67= A9 10       ).
STA &E6         :\ FD69= 85 E6       .f

.LFD6B
LDX #&08        :\ FD6B= A2 08       ".
JSR LFCE8       :\ FD6D= 20 E8 FC     h|
JMP LFD1D       :\ FD70= 4C 1D FD    L.}

.LFD73
LDA &E7         :\ FD73= A5 E7       %g
EOR #&60        :\ FD75= 49 60       I`
STA &E7         :\ FD77= 85 E7       .g
BCS LFD84       :\ FD79= B0 09       0.

.LFD7B
AND #&05        :\ FD7B= 29 05       ).
ROL &7001       :\ FD7D= 2E 01 70    ..p
ROL A           :\ FD80= 2A          *
JSR LFCBF       :\ FD81= 20 BF FC     ?|
.LFD84
JMP LFE73       :\ FD84= 4C 73 FE    Ls~
 
.LFD87
LDY &E0         :\ FD87= A4 E0       $`
JSR LFE44       :\ FD89= 20 44 FE     D~
LDA (&DE),Y     :\ FD8C= B1 DE       1^
EOR &E1         :\ FD8E= 45 E1       Ea
BMI LFD94       :\ FD90= 30 02       0.
EOR #&60        :\ FD92= 49 60       I`
.LFD94
SBC #&20        :\ FD94= E9 20       i 
JMP LFDC2       :\ FD96= 4C C2 FD    LB}
 
.LFD99
LDA #&5F        :\ FD99= A9 5F       )_
.LFD9B
EOR #&20        :\ FD9B= 49 20       I 
BNE LFDC2       :\ FD9D= D0 23       P#
.LFD9F
EOR &E7         :\ FD9F= 45 E7       Eg
.LFDA1
BIT &7001       :\ FDA1= 2C 01 70    ,.p
BMI LFDA8       :\ FDA4= 30 02       0.
EOR #&60        :\ FDA6= 49 60       I`
.LFDA8
JMP LFDB8       :\ FDA8= 4C B8 FD    L8}
 
.LFDAB
ADC #&39        :\ FDAB= 69 39       i9
BCC LFDA1       :\ FDAD= 90 F2       .r
.LFDAF
EOR #&10        :\ FDAF= 49 10       I.

.LFDB1
BIT &7001       :\ FDB1= 2C 01 70    ,.p
BMI LFDB8       :\ FDB4= 30 02       0.
EOR #&10        :\ FDB6= 49 10       I.
.LFDB8
CLC             :\ FDB8= 18          .
ADC #&20        :\ FDB9= 69 20       i 

.LFDBB
BIT &7001       :\ FDBB= 2C 01 70    ,.p
BVS LFDC2       :\ FDBE= 70 02       p.
AND #&1F        :\ FDC0= 29 1F       ).
.LFDC2
JMP LFE39       :\ FDC2= 4C 39 FE    L9~
 
.LFDC5
LDA &DE         :\ FDC5= A5 DE       %^
LDY &DF         :\ FDC7= A4 DF       $_
CPY #&41        :\ FDC9= C0 41       @A
BCC LFE05       :\ FDCB= 90 38       .8
CMP #&E0        :\ FDCD= C9 E0       I`
BCC LFE05       :\ FDCF= 90 34       .4
LDY &E6         :\ FDD1= A4 E6       $f
BMI LFDE1       :\ FDD3= 30 0C       0.
DEY             :\ FDD5= 88          .
BNE LFDDF       :\ FDD6= D0 07       P.
.LFDD8
JSR LFE4A       :\ FDD8= 20 4A FE     J~
BCS LFDD8       :\ FDDB= B0 FB       0{
LDY #&10        :\ FDDD= A0 10        .
.LFDDF
STY &E6         :\ FDDF= 84 E6       .f
.LFDE1
LDY #&20        :\ FDE1= A0 20         
JSR LFE3F       :\ FDE3= 20 3F FE     ?~
.LFDE6
LDA &4000,Y     :\ FDE6= B9 00 40    9.@
STA &3FE0,Y     :\ FDE9= 99 E0 3F    .`?
INY             :\ FDEC= C8          H
BNE LFDE6       :\ FDED= D0 F7       Pw
JSR LFE44       :\ FDEF= 20 44 FE     D~
.LFDF2
LDA &4100,Y     :\ FDF2= B9 00 41    9.A
STA &40E0,Y     :\ FDF5= 99 E0 40    .`@
INY             :\ FDF8= C8          H
BNE LFDF2       :\ FDF9= D0 F7       Pw
LDY #&1F        :\ FDFB= A0 1F        .
LDA #&20        :\ FDFD= A9 20       ) 
.LFDFF
STA (&DE),Y     :\ FDFF= 91 DE       .^
DEY             :\ FE01= 88          .
BPL LFDFF       :\ FE02= 10 FB       .{
RTS             :\ FE04= 60          `
 
.LFE05
ADC #&20        :\ FE05= 69 20       i 
STA &DE         :\ FE07= 85 DE       .^
BNE LFE0D       :\ FE09= D0 02       P.
INC &DF         :\ FE0B= E6 DF       f_
.LFE0D
RTS             :\ FE0D= 60          `
 
.LFE0E
DEY             :\ FE0E= 88          .
BPL LFE2A       :\ FE0F= 10 19       ..
LDY #&1F        :\ FE11= A0 1F        .
.LFE13
LDA &DE         :\ FE13= A5 DE       %^
BNE LFE22       :\ FE15= D0 0B       P.
LDX &DF         :\ FE17= A6 DF       &_
CPX #&40        :\ FE19= E0 40       `@
BNE LFE22       :\ FE1B= D0 05       P.
PLA             :\ FE1D= 68          h
PLA             :\ FE1E= 68          h
JMP LFD3E       :\ FE1F= 4C 3E FD    L>}
 
.LFE22
SBC #&20        :\ FE22= E9 20       i 
STA &DE         :\ FE24= 85 DE       .^
BCS LFE2A       :\ FE26= B0 02       0.
DEC &DF         :\ FE28= C6 DF       F_
.LFE2A
RTS             :\ FE2A= 60          `

\ Write a character to VDU
\ ------------------------
.LFE2B
JSR LFED4       :\ Send to printer
PHP             :\ FE2E= 08          .
PHA             :\ FE2F= 48          H
CLD             :\ FE30= D8          X
STY &E5         :\ FE31= 84 E5       .e
STX &E4         :\ FE33= 86 E4       .d
JSR LFCBF       :\ FE35= 20 BF FC     ?|
PLA             :\ FE38= 68          h
.LFE39
LDX &E4         :\ FE39= A6 E4       &d
LDY &E5         :\ FE3B= A4 E5       $e
PLP             :\ FE3D= 28          (
RTS             :\ FE3E= 60          `
 
.LFE3F
BIT &7002:BPL LFE3F   :\ Wait until no VSync
.LFE44
BIT &7002:BMI LFE44   :\ Wait until VSync
RTS

.LFE4A
LDY #&3B        :\ FE4A= A0 3B        ;
CLC             :\ FE4C= 18          .
LDA #&20        :\ FE4D= A9 20       ) 
.LFE4F
LDX #&0A        :\ FE4F= A2 0A       ".
.LFE51
BIT &7001       :\ FE51= 2C 01 70    ,.p
BEQ LFE5E       :\ FE54= F0 08       p.
INC &7000       :\ FE56= EE 00 70    n.p
DEY             :\ FE59= 88          .
DEX             :\ FE5A= CA          J
BNE LFE51       :\ FE5B= D0 F4       Pt
LSR A           :\ FE5D= 4A          J
.LFE5E
PHP             :\ FE5E= 08          .
PHA             :\ FE5F= 48          H
LDA &7000       :\ FE60= AD 00 70    -.p
AND #&F0        :\ FE63= 29 F0       )p
STA &7000       :\ FE65= 8D 00 70    ..p
PLA             :\ FE68= 68          h
PLP             :\ FE69= 28          (
BNE LFE4F       :\ FE6A= D0 E3       Pc
RTS             :\ FE6C= 60          `


\ OSRDCH HANDLER
\ ============== 
.LFE6D
PHP             :\ FE6D= 08          .
CLD             :\ FE6E= D8          X
STX &E4         :\ FE6F= 86 E4       .d
STY &E5         :\ FE71= 84 E5       .e
.LFE73
BIT &7002       :\ FE73= 2C 02 70    ,.p
BVC LFE7D       :\ FE76= 50 05       P.
JSR LFE4A       :\ FE78= 20 4A FE     J~
BCC LFE73       :\ FE7B= 90 F6       .v
.LFE7D
JSR LFB5D       :\ FE7D= 20 5D FB     ]{
.LFE80
JSR LFE4A:BCS LFE80
JSR LFE4A:BCS LFE80
.LFE8A
TYA             :\ FE8A= 98          .
LDX #&17        :\ FE8B= A2 17       ".
JSR LFE9E       :\ FE8D= 20 9E FE     .~
.LFE90
LDA LFEBC,X:STA &E2
LDA #LFD11 DIV 256:STA &E3
TYA:JMP (&00E2)
 
.LFE9D
DEX
.LFE9E
CMP LFEA4,X:BCC LFE9D
RTS

.LFEA4
EQUB &00:EQUB &08:EQUB &09:EQUB &0A  :\ WRCH character translation table
EQUB &0B:EQUB &0C:EQUB &0D:EQUB &0E
EQUB &0F:EQUB &1E:EQUB &7F

EQUB &00:EQUB &01:EQUB &05:EQUB &06  :\ RDCH character translation table
EQUB &08:EQUB &0E:EQUB &0F:EQUB &10
EQUB &11:EQUB &1C:EQUB &20:EQUB &21
EQUB &3B

\ WRCH and RDCH character translation dispatch table
\ Low byte of addresses - high byte is LFD11 DIV 256
\ --------------------------------------------------
.LFEBC
\ WRCH translation addresses
EQUB LFD1D AND 255 :\ VDU 0
EQUB LFD35 AND 255 :\ VDU 8
EQUB LFD11 AND 255 :\ VDU 9
EQUB LFD3B AND 255 :\ VDU 10
EQUB LFD60 AND 255 :\ VDU 11
EQUB LFD42 AND 255 :\ VDU 12
EQUB LFD19 AND 255 :\ VDU 13
EQUB LFD66 AND 255 :\ VDU 14
EQUB LFD6B AND 255 :\ VDU 15
EQUB LFD56 AND 255 :\ VDU 30
EQUB LFD29 AND 255 :\ VDU 127

\ RDCH translation addresses
EQUB LFDB8 AND 255 :\ 0
EQUB LFDAB AND 255 :\ 1
EQUB LFD73 AND 255 :\ 5
EQUB LFD7B AND 255 :\ 6
EQUB LFDBB AND 255 :\ 8
EQUB LFD87 AND 255 :\ 14
EQUB LFD99 AND 255 :\ 15
EQUB LFDB8 AND 255 :\ 16
EQUB LFDB1 AND 255 :\ 17
EQUB LFDAF AND 255 :\ 28
EQUB LFDA1 AND 255 :\ 32
EQUB LFD9F AND 255 :\ 33
EQUB LFD9B AND 255 :\ 49

.LFED4
PHA
CMP #&02:BEQ LFF00
CMP #&03:BEQ LFF11
CMP &FE:BEQ LFF0F        :\ *BUG* This is Atom location, but is BBC FAULT pointer
LDA &780C
AND #&0E:BEQ LFF0F
PLA
.LFEE9
BIT &7801       :\ FEE9= 2C 01 78    ,.x
BMI LFEE9       :\ FEEC= 30 FB       0{
STA &7801       :\ FEEE= 8D 01 78    ..x
PHA             :\ FEF1= 48          H
LDA &780C       :\ FEF2= AD 0C 78    -.x
AND #&F0        :\ FEF5= 29 F0       )p
ORA #&0C        :\ FEF7= 09 0C       ..
STA &780C       :\ FEF9= 8D 0C 78    ..x
ORA #&02        :\ FEFC= 09 02       ..
BNE LFF0C       :\ FEFE= D0 0C       P.
.LFF00
LDA #&7F        :\ FF00= A9 7F       ).
STA &7803       :\ FF02= 8D 03 78    ..x
LDA &780C       :\ FF05= AD 0C 78    -.x
AND #&F0        :\ FF08= 29 F0       )p
ORA #&0E        :\ FF0A= 09 0E       ..
.LFF0C
STA &780C       :\ FF0C= 8D 0C 78    ..x
.LFF0F
PLA             :\ FF0F= 68          h

\ DEFAULT OSGBPB, IRQ2 HANDLER
\ ============================
\ *BUG* IRQ2V should point to RTI
.LFF10
RTS             :\ FF10= 60          `
 
.LFF11
LDA &780C       :\ FF11= AD 0C 78    -.x
AND #&F0        :\ FF14= 29 F0       )p
BCS LFF0C       :\ FF16= B0 F4       0t


\ RESET HANDLER
\ =============
.LFF18
LDX #&19
.LFF1A
LDA LFF88,X:STA irq1v,X   :\ Set up default vectors
DEX:BPL LFF1A:TXS         :\ Clear stack
TXA:INX
STX &EA:STX &E1:STX &E7   :\ Clear some locations
LDA #&0A:STA &FE          :\ Atom PrintIgnore character
:                         :\ *BUG* This is BBC FAULT address
LDA #&8A:STA &7003        :\ Set up 8255
LDA #&07:STA &7002
JSR LF7C0                 :\ Print inline text
EQUB 6:EQUB 12:EQUB 15    :\ Enable VDU, clear screen, paged off
EQUS "BBC BASIC"
EQUB 10:EQUB 10:EQUB 13
:                         :\ Set up 6522
LDA #&0E:STA &7804        :\ T1=&270E for 100Hz IRQs
LDA #&27:STA &7805        :\
LDA #&40:STA &780B        :\ AuxCtrl=
LDA #&C0:STA &780E        :\ Enable T1 IRQs
LDA #&00:LDX #&04         :\
.LFF64
STA &0300,X:DEX:BPL LFF64 :\ Set TIME to zero
STA &0316:STA &0317       :\ Set SOUND duration to zero
STA &FF                   :\ Clear Escape flag
LDA #&0E:STA &FD          :\ *BUG* Should fetch from &8007
LDA #&80:STA &FE          :\ Point last error to BASIC copyright message
LDA &C000                 :\ Is extension ROM present?
CMP #&AA:BNE LFF85        :\ No, skip past
JSR &C001:CLI             :\ Call extension ROM
.LFF85
JMP &8000                 :\ Enter BASIC at &8000

\ DEFAULT VECTORS
\ ===============
.LFF88
             :\ &200 - NMIV, initialised by DOS
             :\ &202 - BRKV, initialised by BASIC
EQUW &8000   :\ &204 - IRQ1V
EQUW LFF10   :\ &206 - IRQ2V
EQUW LF775   :\ &208 - CLIV
EQUW LF0D2   :\ &20A - BYTEV
EQUW LF000   :\ &20C - WORDV
EQUW LF54F   :\ &20E - WRCHV
EQUW LFE6D   :\ &210 - RDCHV
EQUW LF71A   :\ &212 - FILEV
EQUW LF908   :\ &214 - ARGSV
EQUW LFBC1   :\ &216 - BGETV
EQUW LFC51   :\ &218 - BPUTV
EQUW LFF10   :\ &21A - GBPBV
EQUW LFC0B   :\ &21C - FINDV
             :\ &21E - FSCV

\ IRQ HANDLER
\ ===========
.LFFA2
STA &98:PLA:PHA          :\ Get pushed flags from stack
AND #&10:BNE LFFBA       :\ Jump if BRK occured
LDA &780D:AND #&60       :\ Check 6522 Timer1/Timer2 interupt status
BEQ LFFB4:JMP LF1A7      :\ Jump to process 6522 interupt
.LFFB4
LDA &98:PHA:JMP (irq1v)  :\ Unrecognised, pass on to IRQ1V

\ BRK occured, set up error pointer and pass on to BRKV
\ -----------------------------------------------------
.LFFBA
LDA &98:PLP
PLA:SEC:SBC #&01:STA &FD
PLA:SBC #&00:STA &FE            :\ &FD/E=>error

.OSBRK  :\ &FFC8 : JMP (brkv)   :\ Pass to BRKV
.OSIRQ2 :\ &FFCB : JMP (irq2v)  :\ Pass to IRQ2V
:
\ Filing system entry points
\ --------------------------
.OSFIND :\ &FFCE : JMP (findv)
.OSGBPB :\ &FFD1 : JMP (gbpbv)
.OSBPUT :\ &FFD4 : JMP (bputv)
.OSBGET :\ &FFD7 : JMP (bgetv)
.OSARGS :\ &FFDA : JMP (argsv)
.OSFILE :\ &FFDD : JMP (filev)
:
\ MOS I/O entry points
\ --------------------
.OSRDCH :\ &FFE0 : JMP (rdchv)
.OSASCI :\ &FFE3 : CMP #&0D:BNE OSWRCH
.OSNEWL :\ &FFE7 : LDA #&0A:JSR OSWRCH
.OSWRCR :\ &FFEC : LDA #&0D
.OSWRCH :\ &FFEE : JMP (wrchv)
.OSWORD :\ &FFF1 : JMP (wordv)
.OSBYTE :\ &FFF4 : JMP (bytev)
.OS_CLI :\ &FFF7 : JMP (cliv)
:
.NMI    :EQUW LFCFE
.RESET  :EQUW LFF18
.IRQ    :EQUW LFFA2
]:NEXT
OSCLI"Save "+outfile$+" "+STR$~mcode%+" "+STR$~O%+" "+STR$~load%+" "+STR$~load%
ON ERROR ON ERROR OFF:END
*Quit
:
DEFFNif(A%):IFA%:z%=-1:=opt% ELSE z%=P%:=opt%
DEFFNendif:IFz%=-1:=opt% ELSE z%=P%-z%:P%=P%-z%:O%=O%-z%:=opt%
DEFFNelse:IFz%=-1:z%=P%:=opt% ELSE z%=P%-z%:P%=P%-z%:O%=O%-z%:z%=-1:=opt%