in Hardware, Retro computing

Restoring 486 pc from the junkyard

Working on another PC from junkyard.

Initial look of this poor guy.
Front panel
Some kind of ISA network card
I/O, FDD controller with Goldstar Prime 2
Trident video card
Inside of the case
Am486DX4-100 CPU#

Page with Chaintech motherboard support information and bios updates.


Manufacture: Chaintech 4SPI
Chipset: SiS 85C496/7
BIOS String: 02/16/95-SiS-496-497/A/B-2A4IBC31-B2
BIOS Version: Award v4.50G

Chaintech 4SPI bios information
Chaintech 4SPI motherboard
Chaintech 486SPI motherboard manual / jumper settings:

Cleaning process 🙂


CPU fan holder was broken, so I have 3d printed mount for a CPU heatsink holder and then hot-glued old fan case to it. Seems to work ok for the moment.

PCU fan was realllllllly noisy, so I have replaced the PSU fan with some other I had, much quieter.


Strange thing. After setting the date and time in bios and with a new CMOS battery I have noticed that after restart yar is set to 2094. So either it is some kind of BIOS y2k bug or issue with a motherboard.

Found someone wondering about same issue here.

This Vogon thread was helpful and lead to this page where some flash update was found.

From Chaintech FAQ:

One of the most frequently asked questions concerning 486 mainboards is the ability to address large capacity (>1GB) harddrives on these boards. Due to the limitations of the chipsets on these boards it is not possible to directly address these type of harddrives. It is necessary to use third party software such as OnTrack`s DiskManager (or similar) to address the total space of these harddrives. Due to the limitations of the 486 board`s chipsets it is also not possible to fully benefit from advanced features of these harddrives such as higher performance (PIO mode 4, Ultra DMA/33) and other Enhanced IDE`s benefits.

None of the Chaintech 486 mainboard’s BIOS updates is fully Y2K compliant. In order to address this issue, Chaintech provides a utility, the TSR2000, which should be installed just before the year change 1999-2000. After the year change has passed, you can remove this utility. For more information on this Y2K issue please refer to the  Y2K section on this website.

All Chaintech Mainboards using a BIOS with a datecode of later than June 1996 are 100% Year 2000 Compliant !

See also WWW.AWARD.COM for more information on this issue

All Chaintech Mainboards using a BIOS with a datecode of earlier than June 1996 (mostly 486/386 models) can use our Chaintech TSR2000 software program to become 100% Year 2000 Compliant !

Under Windows 95/98 it is not necessary to use the TSR2000, even when using an older BIOS version.

Bios tools.

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