IBIN-PS/2

@6571.ADF IBIN-PS/2 Interface Card [IBM INterface or IBIN]
Interface for IBM PS/2 and Compatibles with MC Architecture 501-911-01B 





J1 PS/2 Edge Connector
J2 DB25 port
U1 8254
U2 74LS367
U3 74LS240
U4 74LS175
U5 74LS138
U6 74LS139
U7 74LS74
U8,9,14 16L8
U10 74LS14
 U11 74LS794
U12,13  74LS38
U15 74LS645
U16 74LS163
U17 74LS794
U18 74LS688
U19 74LS645
U20 74ALS533
U21 74LS373
U22 7400
U23 74LS00

J11 is the DB25 port on the 500/575 system board.


 1 N.C
 2 MBD0
 3 MBD1
 4 MBD2
 5 MBD3
 6 MBD4
 7 MBD5
 8 MBD6
 9 MBD7
10 /MBSEL
11 MBR/W
12 PCGND
13 N.C.
 14 PCPWR
15 /MBA4
16 /MBA3
17 /MBA2
18 /MBA1
19 /MBA0
20 /MBIRQ
21 PCPWR
22 PCVCC
23 DGND
24 DGND
25 PCGND
0

Pins 14,21 are PCPWR. These pins supply power for the analog power supply in external devices. This power should be routed direct from the PS2 edge connector.

Pin 22 is PCVCC. This pin provides VCC power to the external devices. This power should be routed from the power grid on this ASSY [adapter, I assume]

PCVCC and PCPWR should be tied together at the PS2 edge connector only to reduce noise in the external equipment tied to J2.

GND on Pins 12,25 is PCGND, this GND should be run direct to the PS2 edge connector to minimize noise in chassis connected to J2.

GND on Pins 23,24 is DGND. This should run to the GND net of this circuit directly. DGND and PCGND should be tied together only at the PS2 edge connector.