oldcomp:packard_386sx

Packard 386 SBC board

This is the processor board from a Packard 500TR flow scintillation analyser. My board came from the unit in DextersTechLab's teardown video.

It's essentially an ISA-bus 386 PC on an ISA card.

Part numbers on the PCB:

  • 7101196
  • 5091196-G
  • 1310067 REV A (on PAL chip)
  • 1310068 REV E (on BIOS chip)

Features:

  • 80386SX processor, 16 MHz (chip rated at 25 MHz)
  • 8x 30-pin SIMM slots (2x 512K modules fitted for a total of 1MB RAM)
  • Chips & Technologies 82C836 “SCATsx” chipset
  • Chips & Technologies 82C710 Super I/O
    • 1x IDE channel
    • 1x floppy drive port
    • PS/2 mouse port
  • Chips & Technologies 8042 keyboard controller
    • Standard pinout
    • Keyboard port, Keylock (keyboard inhibit), A20 line
  • Chips & Technologies BIOS

The standard backup battery is a 3.6V lithium thionyl chloride cell.

Unfortunately a 3V coin cell is not suitable: the board has a very high discharge current. Three AA NiMH or alkaline cells may be a better replacement.

3-pin 0.1in-pitch header

Pins from left to right, with the RAM slots held at the left.

1 2 3
notch
1
2 MAX891 pin 11 (Watchdog In)
3 0V

This is likely a reset switch input.

5-pin 0.1in-pitch header

Pins from left to right, with the RAM slots held at the left.

1 2 3 4 5
notch
1 Mouse Data (82C710 pin 61)
2
3 0V
4 5V via fuse
5 Mouse Clock (82C710 pin 60)

10-pin IDC connector

Pins from left to right, with the RAM slots held at the left.

1 3 5 7 9
2 4 6 8 10
notch
1 Keyboard Data
2 Keyboard Clock
3 0V
4
5 5V
6
7
8
9
10

Mounted flat to the PCB. 8-pin (4×2) 0.1in-pitch Dupont connector.

Pins from left to right, with the RAM slots held at the left.

PCB
1 3 5 7
2 4 6 8
1 Power LED + – via 150R to +5V
2 Power LED - – to 0V
3 Keylock switch 0V
4 Keylock, connect to 0V to lock – to 8042 pin 34
5 Hard drive LED + – via 200R to +5V
6 Hard drive LED -
7 PC Speaker – via fuse to +5V
8 PC Speaker – via 33R to drive circuit
  • JMP1: (Unknown) - Connects to 8042 pin 33. Display Type jumper?
  • JMP2: (Unknown) - normally set right. Sets centre pin to either 0V or 5V
  • JMP3: Not fitted
  • JMP4: 4-pin, unknown function
  • JMP5: Not fitted
  • JMP6: (Unknown) - normally set right.
  • JMP7: CMOS Clear. Up (2-3) to clear CMOS. Down (1-2) for normal operation
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  • Last modified: 2024/05/05 13:53
  • by philpem