Two Port Parallel Card
661-93138
PIN NAME PIN NAME
1 GND 14 GND
2 GND 15 PSTRB
3 RW 16 BSY
4 GND 17 CMD
5 DDO 18 PARITY
6 DD1 19 OCD
7 N.C. 20 GND
8 DD2 21 CRES
9 GND 22 DD3
10 GND 23 DD4
11 DD5 24 GND
12 DD6 25 CHK
13 DD7
The meanings of the individual signals on the interface are:
D0-D7: Eight bidirectional data lines. Bit D7 is the MSB.
DRW: This line is driven high by the Lisa to indicate that data is
expected to be input on the data lines. It is driven low to indicate
that data is being output.
PARITY: Bidirectional line which must be configured on the basis of the data
currently on the data lines to give odd parity.
PSTRB: Processor strobe line used as a signal by the Lisa to indicate valid
data being output.
CMD: This line is asserted by the Lisa to indicate that a command has been
placed on the data lines.
BSY: This line is asserted by the peripheral to indicate to the Lisa that
it is busy and unable to process commands on the interface.
OCD: The Lisa monitors this line. If it is high, it is assumed that no
device is connected to the interface.
CRES: This line is asserted by the Lisa when the peripheral is to be reset
to its power-on state.
CHK: This signal may be used to interrupt the CPU in the event that a
fault condition has occurred in the device connected to the
interface.
NOTE: These pinouts apply to both the upper and lower connector of a two port
parallel card installed in a Lisa or Macintosh XL.