Prometheus CPU User Manual V1.44
Page 15
4.11 PC/104 Bus Connectors
The PC/104 bus is essentially identical to the ISA Bus except for the physical design. It specifies
two pin and socket connectors for the bus signals. A 64-pin header J1 incorporates the 62-pin 8-
bit bus connector signals, and a 40-pin header J2 incorporates the 36-pin 16-bit bus connector
signals. The additional pins on the PC/104 connectors are used as ground or key pins. The
female sockets on the top of the board enable stacking another PC/104 board on top of the board,
while the male pins on the bottom enable the board to plug into another board below it.
In the pinout figures below, the tops correspond to the left edge of the connector when the board
is viewed from the primary side (side with the CPU chip and the female end of the PC/104
connector) and the board is oriented so that the PC/104 connectors are along the bottom edge of
the board.
View from Top of Board
J2: PC/104 16-bit bus connector
J1: PC/104 8-bit bus connector
Ground
D0
C0 Ground
IOCHCHK- A1
B1 Ground
MEMCS16-
D1
C1 SBHE-
SD7 A2
B2 RESET
IOCS16-
D2
C2 LA23
SD6 A3
B3 +5V
IRQ10
D3
C3 LA22
SD5 A4
B4 IRQ9
IRQ11
D4
C4 LA21
SD4 A5
B5 -5V
IRQ12
D5
C5 LA20
SD3 A6
B6 DRQ2
IRQ15
D6
C6 LA19
SD2 A7
B7 -12V
IRQ14
D7
C7 LA18
SD1 A8
B8 0WS-
DACK0-
D8
C8 LA17
SD0 A9
B9 +12V
DRQ0
D9
C9 MEMR-
IOCHRDY A10 B10
Key (pin cut)
DACK5-
D10 C10 MEMW-
AEN A11 B11 SMEMW-
DRQ5
D11 C11 SD8
SA19 A12 B12 SMEMR-
DACK6-
D12 C12 SD9
SA18 A13 B13 IOW-
DRQ6
D13 C13 SD10
SA17 A14 B14 IOR-
DACK7-
D14 C14 SD11
SA16 A15 B15 DACK3-
DRQ7
D15 C15 SD12
SA15 A16 B16 DRQ3
+5V
D16 C16 SD13
SA14 A17 B17 DACK1-
MASTER-
D17 C17 SD14
SA13 A18 B18 DRQ1
Ground
D18 C18 SD15
SA12 A19 B19 Refresh-
Ground
D19 C19
Key (pin cut)
SA11
A20 B20 SYSCLK
SA10
A21 B21 IRQ7
SA9
A22 B22 IRQ6
SA8
A23 B23 IRQ5
SA7
A24 B24 IRQ4
SA6
A25 B25 IRQ3
SA5
A26 B26 DACK2-
SA4
A27 B27 TC
SA3
A28 B28 BALE
SA2
A29 B29 +5V
SA1
A30 B30 OSC
SA0
A31 B31 Ground
Ground
A32 B32 Ground
