AMD 486 PC tower with 14″ monitor, keyboard and MS mouse
I restored this 1994 PC for fun. It was a powerful computer in its day, with a 486 class 66 MHz cpu, 16 MB of RAM, 170 MB hard disk, sound card, CD-ROM and the latest Microsoft Operating Systems DOS 6.22 and Windows for Workgroups 3.11.
It is interesting to see how computers have changed in 20 years. Notice the specifications for this PC are in Megabytes and Megahertz, not the usual Gigabytes and Gigahertz that we are used to seeing today. Some of the features are quite outdated like coaxial Ethernet, serial ports, and configuring expansion cards with jumpers.
Read on for the specifications, a video of the PC booting and running, pictures of the restoration process and PDF scans of the original documentation.
Watch the PC boot and run Windows -
Specifications
- AMD Am486DX2 66 MHz CPU
- 486SH VL-Bus System Board with 3 32-bit VESA local bus slots, 6 ISA bus slots and 1 8-bit ISA slot, 8 SIMM memory module slots, cache and green features (cpu-clock slow down and monitor shut down features)
- Tower case
- 230 watt power supply
- 16 MB memory – 4 4 MB SIMM memory modules
- hard disk – 170 MB Western Digital Caviar 1170
- 5 1/4″ floppy drive – 1.2 MB high density TEAC FD-55GFR
- 3 1/2″ floppy drive – 1.44 MB
- sound card – SoundBlaster 16-bit with SCSI-2 interface
- CD-ROM – Matshita CR-504 SCSI 4x
- video card – Kelvin Orchid 64 VESA
- VL-bus Super I/O card with support for 2 IDE cables, 1 floppy disk cable, 2 serial ports, LPT printer port
- NIC, generic, 10 Mbps with RJ-45 and Thin-Wire Ethernet connectors
- System board has a DIN keyboard connector
- Mouse – Microsoft 2 button with a 9 pin serial connector
- 14″ CRT monitor
Restoring the PC
The system was complete and booted when I dug it out of the garage but was filthy and the cpu heat sink had broken off. I stripped it down, cleaned it up, took photographs scanned the expansion card manuals. I made a bracket to hold the heat sink on with baling wire. I added a 5 1/4″ floppy disk drive.
PC getting stripped down for restore. Note broken heat sink lower right.
heat sink secured with bailing wire
Components and their PDF manuals
AMD Am486 DX2-66 CPU
Wikipedia article on the AMD Am486 CPU.
System board
System Board
486SH_VL-Bus_System_Board_User’s_Manual_Revision_1.1
Orchid Kelvin 64 video card
Orchid Kelvin 64 video card
Orchid_Kelvin_64_video_card_User’s_Manual
NIC
NIC
Super I/O card
Super I/O card
PTI-255W_VL-Bus_Super_IO_Card_User’s_Guide
SoundBlaster sound and SCSI card
SoundBlaster 16-bit Multimedia Audio Card with SCSI-2 Interface
SoundBlaster_16-bit_Multimedia_Audio_Card_SCSI-2_Interface_User’s_Guide
CMOS standard setup screen
CMOS standard setup screen
Setup disks
- DOS 6.22 (3 disks)
- Windows for Workgroups (8 disks)
- TCP/IP protocol add on disk for WfW (1 disk)
- MS Mouse driver (1 disk)
Setup disks.
config.sys
DEVICE=C:\EZSCSI50\ASPI2DOS.SYS /D /Z
DEVICE=C:\EZSCSI50\ASPICD.SYS /D:ASPICD0
DEVICE=C:\SB16\DRV\CTSB16.SYS /UNIT=0 /BLASTER=A:220 I:5 D:1 H:5
DEVICE=C:\SB16\DRV\CTMMSYS.SYS
FILES=40
DEVICE=C:\DOS\SETVER.EXE
DEVICE=C:\WINDOWS\HIMEM.SYS
DOS=HIGH
REM ** FILES=30
LASTDRIVE=Z
DEVICE=C:\WINDOWS\IFSHLP.SYS
STACKS=9,256
autoexec.bat
C:\DOS\MSCDEX.EXE /D:ASPICD0 /M:12
SET SOUND=C:\SB16
SET BLASTER=A220 I5 D1 H5 P330 T6
SET MIDI=SYNTH:1 MAP:E
C:\SB16\DIAGNOSE /S
C:\SB16\MIXERSET /P /Q
C:\WINDOWS\net start
C:\DOS\SMARTDRV.EXE /X
@ECHO OFF
PROMPT $p$g
PATH C:\WINDOWS;C:\DOS
SET TEMP=C:\DOS
Notes on the project
I had forgotten how modular computers were back then. The mother board only held the cpu, memory, cache and expansion slots – no integrated features like video, sound, NIC and I/O. Today’s mother boards typically include video, sound, NIC and I/O features. The CPU contains its cache on the die.
PCs had to be manually configured for interrupts and I/O memory, typically with jumpers or configuration programs. Today we have Plug-and-Play to automatically set these parameters.
Some I/O ports and devices have disappeared – serial ports, printer ports and floppy disks. USB, FireWire and SATA have taken their place. IDE and floppy ports are disappearing. The keyboard port has shrunk from full size DIN to mini DIN or has been replaced by USB.
The speeds of CPUs, memory, buses, disks and Ethernet have all improved a lot. New devices like WiFi, solid state storage, writeable optical media have changed computing. Laptops, mobile phones and tablets have changed computing even more.
Operating Systems and software are always growing and demanding more computer resources, one reason we need bigger and faster computers all the time. I was amused at how well DOS 6 and Windows 3 ran on the slim resources of a 66 MHz processor with 16 MB RAM.
Both the system board and video card mention “green” features for power conservation, early energy and environment awareness. Please recycle electronic waste.
Back in the day there were stores that built and repaired computers. This one was originally built and sold by Zoommax Computers, Sacramento, California.
Zoommax logo PC