💾 Archived View for uscoffings.net › retro-computing › collection › ibm-5150 captured on 2023-09-28 at 16:44:38. Gemini links have been rewritten to link to archived content

-=-=-=-=-=-=-

IBM PC 5150

The System

IBM PC 5150 in mint condition
16k-64k motherboard with v2 BIOS - P/N 184041XM413 - S/N 0216354
Dual full height 320k floppy drives
IBM floppy controller - P/N 1809121 XM 42
IBM MDA and parallel port - P/N 1804057 362XM
IBM power supply - P/N 1800841
Everex EV-138 memory card with 576K (maxed)
IBM 5151 monitor
Model F Keyboard
Original purchase invoice from 1982!
IBM DOS 3.3

Log

*20110223** Purchased from Vintage Computer Marketplace from the original owner. I learned after bidding that if it hadn't sold, it was destined for the big electronics grinder in the sky. So sad!

Vintage Computer Marketplace (seems to be defunct)

*20150829**

Disassembled, cleaned, and reassembled everything. Both floppy drives work. Motherboard has the v2 BIOS, which does not support hard drives, and does not sense switch 5 of SW2 which limits it to 544KB of RAM. Cleaned latex paint off power cords etc with rubbing alcohol. Cleaned floppy drives.
Glued monitor case cracks with E6000. The back shell of the monitor is somewhat brittle but this stabilized it.
Replacement cork pads from Lorne on Vintage Computer Marketplace. Besides the monitor cracks, everything seems to function correctly.

*2023**

Upgraded BIOS to Oct 82 version.
Installed XT-IDE wtih old 256 MB PATA flash.

Switches

http://www.minuszerodegrees.net/5150/misc/5150_motherboard_switch_settings.htm

SW1 01000001

http://www.minuszerodegrees.net/5150/ram/5150_ram_16_64_SW2.jpg

SW2 00000000

BIOS

My machine originally had the oldest BIOS. This BIOS only recognizes up to 544KB RAM, and does not support hard drives.

... Upgrade BIOS to the 10/27/82 version. This will allow full 640K RAM support, and adds support for expansion ROMs, so the XT-IDE card will be recognized. The original EPROM in this machine is a 36887 made by Mostek, and the EMP-20 apparently does not support this (it's not listed, and configuring as a Motorola 68766 and then reading does not work.) Search for EPROM MCM68766.

I found a MCM68766 EPROM on eBay, Oct '82 BIOS from minuszerodegrees.net, flashed with my EMP-20, and the XT-IDE was recognized.

XT-IDE

...

TODO

NEC V20. Not original but still from the time period.

References

IBM 51xx PC Family Computers

Description at old-computers.com