COMMODORE PC 20-III



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General Technical Information

SYSTEM CPU Intel 8088 @9.54 MHZ (max)*
CACHE
N/A
RAM  640 KB (Max. 640 KB)
SYSTEM BUS WIDTH
8 bit
OPTION BUS 3 x ISA 8 bit slots
GRAPHICS Onboard framebuffer with support for Hercules monochrome, MDA, CGA and Plantronics Color Plus. Hercules monochrome mode is currently in use.
DISPLAY Kaypro 12" Hercules monochrome CRT monitor
HARD DISK  DRIVE
20 MB Western Digital "XT type" disk
FLOPPY DISK DRIVE 5.25" 360K floppy drive
NETWORK N/A
AUDIO PC beeper
OS MS-DOS 6.22
YEAR 1987
SPEED not measured
COMMENTS This is one of Commodore's IBM XT clones, and should be twice as fast as the original XT, because of the doubled CPU clock. It came with 640K RAM which of course was quite enough at the time.
ESTIMATED PRICE 1987
$2,500
*= CPU clock can be adjusted between the settings 9.54 MHz ("double speed"), 7.16 MHz ("turbo speed") and 4.77 MHz ("normal speed").

History and other comments

I bought this computer from a friend back in 1995. It was already rather old at the time, but I had no other PC and I got it for a pretty cheap price. I still remember that I paid 150 FIM for it (FIM = Finnish Markka), which was about 25€. The Commodore PC is completely IBM XT compatible, as far as I could tell, so you could run any standard DOS application on it as long as it was happy with only the 640 KB of base memory.

I when I booted up the system again, 11 years later, I found out that I had been using Stacker, a program very often used on peecees with small hard disks. The program compresses the disk contents on the fly (as if the filesystem was compressed) and only uncompresses files when they are accessed. This could literally double the disk space, but would also make the system considerably slower. I fired up the DOS version of WordPerfect that we had been using 11 years ago, and it was still working. WP always was fast enough to scroll text up and down even on the 8088. WP was more or less a defacto standard for a PC wordprocessor in those days.

The Kaypro green-and-black monitor is really cool these days when we are used to so much better computer screens. It has green glowing text on black background, and when the text scrolls you can still see the traces of where the text had been one second ago.  Also the traces of the mouse pointer are gradually fading. So in other words, this wouldn't really have been the best display for games, but nowadays the coolness factor is very high, look at the photo below (although you would need to see a video clip to see the fading effect):




Last updated:  13-8-2006