# Apple Macintosh Processor-Direct Slot (PDS)

120 PIN Euro-DIN CONNECTOR

Available on Apple Macintosh SE/30 & IIfx

Cards in the PDS are accessed at 20MHz. This speed should let developers create PDS cards without using expensive components while still providing access to the processor bus. There are two locations in the memory map for PDS cards. Developers should see the "Cards and Drivers Manual" for information on creating PDS cards. This manual is available from APDA.

The cache connector in the Macintosh IIci may look like the Macintosh IIfx PDS connector, but the pinouts are vastly different.

Pin | Name | Description
--- | --- | ---
A1 | res | Reserved
A2 | res | Reserved
A3 | /BUSLOCK | Bus Clock
A4 | /IRQ3 | Interrupt Request 3
A5 | /IPL2* | 68030 IPL2
A6 | /CIOUT* | 68030 Cache inhibit out
A7 | /STERM* | Sync.cycle termination
A8 | /DSACK1* | 68030 Data ack 1
A9 | SIZ1 | transfer size bit 1
A10 | /BGACK* | 68030 bus grant ack
A11 | FC2 | 68030 function code 2
A12 | /RESET* | System reset
A13 | D0 | Data bit 0
A14 | D2 | Data bit 2
A15 | D5 | Data bit 5
A16 | D8 | Data bit 8
A17 | D10 | Data bit 10
A18 | D13 | Data bit 13
A19 | D16 | Data bit 16
A20 | D18 | Data bit 18
A21 | D21 | Data bit 21
A22 | D24 | Data bit 24
A23 | D26 | Data bit 26
A24 | D29 | Data bit 29
A25 | A31 | address bit 31
A26 | A29 | address bit 29
A27 | A26 | address bit 26
A28 | A23 | address bit 23
A29 | A21 | address bit 21
A30 | A18 | address bit 18
A31 | A15 | address bit 15
A32 | A13 | address bit 13
A33 | A10 | address bit 10
A34 | A7 | address bit 7
A35 | A5 | address bit 5
A36 | A2 | address bit 2
A37 | +5V | +5 VDC
A38 | CPUCLOCK | CPU Clock
A39 | GND | Ground
A40 | -12V | -12 VDC
B1 | res | Reserved
B2 | GND | Ground
B3 | /TM1A | ?
B4 | /IRQ2 | Interrupt Request 2
B5 | /IPL1* | 68030 IPL1
B6 | /DS* | 68030 Data Strobe
B7 | /CBACK* | cache burst ack
B8 | /DSACK0* | 68030 Data ack 0
B9 | SIZ0 | Transfer Size bit 0
B10 | /BG* | 68030 bus grant
B11 | FC1 | 68030 function code 1
B12 | /BERR* | Bus error
B13 | +5V | +5 VDC
B14 | D3 | Data bit 3
B15 | D6 | Data bit 6
B16 | GND | Ground
B17 | D11 | Data bit 11
B18 | D14 | Data bit 14
B19 | +5V | +5 VDC
B20 | D19 | Data bit 19
B21 | D22 | Data bit 22
B22 | GND | Ground
B23 | D27 | Data bit 27
B24 | D30 | Data bit 30
B25 | +5V | +5 VDC
B26 | A28 | address bit 28
B27 | A25 | address bit 25
B28 | GND | Ground
B29 | A20 | address bit 20
B30 | A17 | address bit 17
B31 | +5V | +5 VDC
B32 | A12 | address bit 12
B33 | A9 | address bit 9
B34 | GND | Ground
B35 | A4 | address bit 4
B36 | A1 | address bit 1
B37 | +5V | +5 VDC
B38 | ECLK | ?
B39 | GND | Ground
B40 | -5V | -5 VDC
C1 | PWROFF | Power Off?
C2 | /NUBUS | ?
C3 | /TM0A | ?
C4 | /IRQ1 | Interrupt Request 1
C5 | /IPL0* | 68030 IPL0
C6 | /RMC* | 68030 read modify cycle
C7 | /CBREQ* | 68030 cache burst req
C8 | R/W* | 68030 read write
C9 | /AS* | 68030 address strobe
C10 | /BR* | 68030 bus request
C11 | FC0 | 68030 function code 0
C12 | /HALT* | 68030 Halt
C13 | D1 | Data bit 1
C14 | D4 | Data bit 4
C15 | D7 | Data bit 7
C16 | D9 | Data bit 9
C17 | D12 | Data bit 12
C18 | D15 | Data bit 15
C19 | D17 | Data bit 17
C20 | D20 | Data bit 20
C21 | D23 | Data bit 23
C22 | D25 | Data bit 25
C23 | D28 | Data bit 28
C24 | D31 | Data bit 31
C25 | A30 | address bit 30
C26 | A27 | address bit 27
C27 | A24 | address bit 24
C28 | A22 | address bit 22
C29 | A19 | address bit 19
C30 | A16 | address bit 16
C31 | A14 | address bit 14
C32 | A11 | address bit 11
C33 | A8 | address bit 8
C34 | A6 | address bit 6
C35 | A3 | address bit 3
C36 | A0 | address bit 0
C37 | +5V | +5 VDC
C38 | C16M | 16 MHz Clock
C39 | GND | Ground
C40 | +12V | +12 VDC

Below a table with differences found in the Apple Macintosh IIfx computers:

Pin | Name | Description
--- | --- | ---
A1 | GND* | Ground
A2 | /PDS.MASTER | ?
A3 | res | Reserved
A4 | n.c. | Not connected
A38 | Reserved | by Apple
B1 | ECS | Early cycle start
B2 | n.c. | Not connected
B3 | /PDS.BG | ?
B4 | /IRQ15 | ?
B38 | n.c. | Not connected
B39 | /SLOT.E | 68030 slot E replace in address map
C1 | /PFW | Shutdown bit
C2 | n.c. | Not connected
C3 | /PDS.BR | Bus request
C4 | /IRQ6 | ?
C38 | CPUCLK* | 20 MHz clock

Contributor: Joakim Ögren

Source:
Apple Tech Info Library 5744: Macintosh SE/30,IIfx: Processor-Direct Slot (PDS) Pinouts at Apple TIL homepage

Copyright © The Hardware Book Team 1996-2001.
May be copied and redistributed, partially or in whole, as appropriate.
Document last modified: 2001-06-07