VIC-20
<computer> A home computer made by Commodore with a 6502 CPU, similar in
style to the Commodore 64 and Commodore C16. The VIC-20 was released before the
C64, and after the Commodore PET(?). It was intended to be more of a low-end
home computer than the PET.
The VIC-20 had connectors for game cartridges and a tape drive (compatible with
a C64). It came with five kilobytes of RAM, but 1.5 KB were used by the system
for various things, like the video display (which had an unusual 22x20 char/line
screen layout), and other dynamic aspects of the operating system (such as it
was). The RAM was expandable with a plug-in cartridge which used the same
expansion port as games. Port expander boxes were available to allow more than
one cartridge to be connected at a time.
RAM cartridges were available in several sizes: 3K, 8K, 16K and 32K. The
internal memory map was re-organised with the addition of each size cartridge,
leading to the situation that some programs would only work if the right amount
of memory was available. The 32K cartridges were all third-party and had
switches to allow the RAM to be enabled in sections so that any expansion size
could be achieved.
BASIC programs could use at most 24 KB of RAM. Any extra occupied the location
usually used by ROM cartridges (i.e. games). This allowed people to copy ROM
cartridges to tape and distribute them to their friends, who could load the tape
into the top 8k of their 32k RAM packs.
The name "VIC" came from the Video Interface Chip that was also used in the
other, later, Commodore 8-bit computers.
(2000-03-28)
Nearby terms:
vhost « VHS « vi « VIC-20 » video adapter »
video card » Video Compact Disc
|