SIMM=Single Inline Memory Module
 (at the computer)
 (at the computer)
72 PIN SIMM at the computer.
| Pin | Non-Parity | Parity | Description | 
|---|---|---|---|
| 1 | VSS | VSS | Ground | 
| 2 | DQ0 | DQ0 | Data 0 | 
| 3 | DQ16 | DQ16 | Data 16 | 
| 4 | DQ1 | DQ1 | Data 1 | 
| 5 | DQ17 | DQ17 | Data 17 | 
| 6 | DQ2 | DQ2 | Data 2 | 
| 7 | DQ18 | DQ18 | Data 18 | 
| 8 | DQ3 | DQ3 | Data 3 | 
| 9 | DQ19 | DQ19 | Data 19 | 
| 10 | VCC | VCC | +5 VDC | 
| 11 | n/c | n/c | Not connected | 
| 12 | A0 | A0 | Address 0 | 
| 13 | A1 | A1 | Address 1 | 
| 14 | A2 | A2 | Address 2 | 
| 15 | A3 | A3 | Address 3 | 
| 16 | A4 | A4 | Address 4 | 
| 17 | A5 | A5 | Address 5 | 
| 18 | A6 | A6 | Address 6 | 
| 19 | A10 | A10 | Address 10 | 
| 20 | DQ4 | DQ4 | Data 4 | 
| 21 | DQ20 | DQ20 | Data 20 | 
| 22 | DQ5 | DQ5 | Data 5 | 
| 23 | DQ21 | DQ21 | Data 21 | 
| 24 | DQ6 | DQ6 | Data 6 | 
| 25 | DQ22 | DQ22 | Data 22 | 
| 26 | DQ7 | DQ7 | Data 7 | 
| 27 | DQ23 | DQ23 | Data 23 | 
| 28 | A7 | A7 | Address 7 | 
| 29 | A11 | A11 | Address 11 | 
| 30 | VCC | VCC | +5 VDC | 
| 31 | A8 | A8 | Address 8 | 
| 32 | A9 | A9 | Address 9 | 
| 33 | /RAS3 | /RAS3 | Row Address Strobe 3 | 
| 34 | /RAS2 | /RAS2 | Row Address Strobe 2 | 
| 35 | n/c | PQ3 | Parity bit 3 (for the 3rd byte, bits 16-23) | 
| 36 | n/c | PQ1 | Parity bit 1 (for the 1st byte, bits 0-7) | 
| 37 | n/c | PQ2 | Parity bit 2 (for the 2nd byte, bits 8-15) | 
| 38 | n/c | PQ4 | Parity bit 4 (for the 4th byte, bits 24-31) | 
| 39 | VSS | VSS | Ground | 
| 40 | /CAS0 | /CAS0 | Column Address Strobe 0 | 
| 41 | /CAS2 | /CAS2 | Column Address Strobe 2 | 
| 42 | /CAS3 | /CAS3 | Column Address Strobe 3 | 
| 43 | /CAS1 | /CAS1 | Column Address Strobe 1 | 
| 44 | /RAS0 | /RAS0 | Row Address Strobe 0 | 
| 45 | /RAS1 | /RAS1 | Row Address Strobe 1 | 
| 46 | n/c | n/c | Not connected | 
| 47 | /WE | /WE | Read/Write | 
| 48 | n/c | n/c | Not connected | 
| 49 | DQ8 | DQ8 | Data 8 | 
| 50 | DQ24 | DQ24 | Data 24 | 
| 51 | DQ9 | DQ9 | Data 9 | 
| 52 | DQ25 | DQ25 | Data 25 | 
| 53 | DQ10 | DQ10 | Data 10 | 
| 54 | DQ26 | DQ26 | Data 26 | 
| 55 | DQ11 | DQ11 | Data 11 | 
| 56 | DQ27 | DQ27 | Data 27 | 
| 57 | DQ12 | DQ12 | Data 12 | 
| 58 | DQ28 | DQ28 | Data 28 | 
| 59 | VCC | VCC | +5 VDC | 
| 60 | DQ29 | DQ29 | Data 29 | 
| 61 | DQ13 | DQ13 | Data 13 | 
| 62 | DQ30 | DQ30 | Data 30 | 
| 63 | DQ14 | DQ14 | Data 14 | 
| 64 | DQ31 | DQ31 | Data 31 | 
| 65 | DQ16 | DQ16 | Data 16 | 
| 66 | n/c | n/c | Not connected | 
| 67 | PD1 | PD1 | Presence Detect 1 | 
| 68 | PD2 | PD2 | Presence Detect 2 | 
| 69 | PD3 | PD3 | Presence Detect 3 | 
| 70 | PD4 | PD4 | Presence Detect 4 | 
| 71 | n/c | n/c | Not connected | 
| 72 | VSS | VSS | Ground | 
| PD2 | PD1 | Size | 
|---|---|---|
| GND | GND | 4 or 64 MB | 
| GND | NC | 2 or 32 MB | 
| NC | GND | 1 or 16 MB | 
| NC | NC | 8 MB | 
| PD4 | PD3 | Accesstime | 
|---|---|---|
| GND | GND | 50, 100 ns | 
| GND | NC | 80 ns | 
| NC | GND | 70 ns | 
| NC | NC | 60 ns | 
Notes: A9 is a N/C on 256k and 512k modules.
A10 is a N/C on 256k, 
512k, 1M and 4M modules.
RAS1/RAS3 are N/C on 256k, 1M and 4M 
modules.