Commodore PC40-III

The beat down looking old PC40-III. Click for more images.

Commodore might have made their fortune with calculators, VIC20s and Commodore 64s, but in the late 80s the Amiga had come along and even with a wonderkind in your product lineup, there's always that one client demanding something IBM compatible. So they let the German engineers loose on the project and lo, the Commodore PC family was born.

These machines are very strange. They have MOS specific chipset parts, NEC and AMD CPUs, oddball hard disk interfaces... they share a lot of infrastructure with the Amiga bridgeboards too. Heck, most these machines have a dedicated port labelled MOUSE that is indeed an Amiga joystick port in disguise. Other fun features are adjustable clock frequency via keyboard shortcuts on the fly... handy for old games that don't want to play nice.

This specific example is a PC40-III, a 286-12 system. It has the same nifty little chassis as the PC10/20-III 8088 variants which are quite a bit more common. It featured a factory 40MB hard disk drive, a high density Chinon floppy drive, built-in VGA graphics, a 12MHz Siemens-sourced 286 and 1MB RAM onboard.

Specifications

Siemens 80286 @ 12MHz (selectable 6, 8 or 12MHz)

Faraday FE3040 "chipset"

1MB RAM

200MB Conner hard disk

Paradise VGA graphics

Creative SoundBlaster 2.0 w/ CMS

Genius GE2000-III 10mbps combo ethernet adapter

MS-DOS 5.0 (upgraded from 3.30)

Windows 3.0a w/ MultiMedia Extensions

Unique features

The MOS "Frankenmouse" mouse port controller which converts Microsoft Bus Mouse signals into Amiga mouse signals is pretty slick, the variable frequency tomfoolery works a treat too. It allegedly even has an RCA mono output on the back for the PC speaker sound, although that doesn't appear to work on my example at this time.

Later revision PC40-IIIs, like this one, use a Dallas clock module. Mine is fitted with a Necroware nWx287. I need to look at replacing the battery holder with something larger, shock surprise the 286 isn't very gentle on clock batteries!

Personal history

My first PC40-III was given to me by a client about 15 years ago as he was about to huck it in a skip!

My current example is significantly cleaner than the first one, and was recovered from a deceased estate. It appeared to be very low hour and still had its working 40MB Western Digital hard disk fitted! I've since upgraded it with a delicious 200MB Conner hard disk and the Creative Sound Blaster 2.0 CT1350B - a true classic which gives Adlib, Creative Music System and traditional SoundBlaster mode, can't ask for much more on a 286!

The icing on the cake is the Genius ethernet adapter which gives the 286 full unbridled access to the RetroWAN and my Windows Home Server. It's a little unhinged seeing IRC functioning on a computer with lineage back to around the time of my birth.

Next planned modifications involve the memory subsystem. Officially the Faraday FE3040 "chipset" can support 256K or 1M DRAM modules, which means in theory it should be able to handle 4MB RAM vs the 1MB that's fitted. Of course, none of this is supplied via SIMMs it's DIP modules soldered into place, and having studied the design with friends we've surmised that with some modification we should be able to add the extra lines needed to implement that. The only other way to add RAM would be fishing up an old Intel AboveBoard or AST RAMpage or something... they're getting hard to come by and very expensive to populate. But more than 1MB will wake up Windows... which only leaves adding a CDROM drive.

Not that CDROM drives on 286s is something that was really a thing, but having found an old Dick Smith advert from the time when this system was still available retail, they were selling it with a CDROM drive kit fitted... let's dream big! I have a classic Mitsumi/Tandy drawer load single speed I'd love to use for it but whether we can get it to work and play ball with the PC40... ehhhh that's another discussion for another time.