A. Connections

All connectors are shown as seen looking into the board.

PL1 STEbus connector

For suitable backplanes refer to current catalogue.

PL2. Disk DMA control connector.

!DACK2	10	o o	9	GND
EOP	8	o o	7	GND
AEN	6	o o	5	GND
nc	4	o o	3	GND
TIMO	2	o o	1	GND

PL3, 4 and 5. PC-compatible keyboard connectors.

These are shown as seen looking into the front of the board.

PL3. Standard connector, as supplied.

	3	nc
	5	5V
	2	Keyboard data (TTL)
	4	0V
	1	Keyboard clock (TTL)

PL4. Alternative Keyboard connector (5-pin Berg).

	1	nc
	2	5V
	3	Keyboard clock (TTL)
	4	Keyboard data (TTL)
	5	0V

PL5. Keyboard connector (4-pin Berg).

	1	nc
	2	5V
	3	Keyboard clock (TTL)
	4	Keyboard data (TTL)
	5	0V

LK1. Reset switch connector (2-pin Berg).

	1	Switch
	2	0V

LK2. Speaker connector (3-pin Berg).

	1	5V
	2	Speaker
	3	0V

The speaker should be connected between +5V and the centre pin of LK2, as the speaker is open-collector driven.