COMPUTE! ISSUE 58 / MARCH 1985 / PAGE 10
VIC-20/Commodore 64
Compatibility
If I expand my VIC's memory, will I be able to run programs written for
the 64?
Jeb Rickert
Only programs written in
straightforward BASIC with few or no PEEKS, POKES, machine language
routines, sound effects, or graphics can be used on the VIC (which
eliminates about 95 percent of Commodore 64 programs). There are
numerous differences between the VIC and 64 that go far beyond memory
size. The 64 has a 40-column by 25-line screen format (versus the VIC's
22-column by 23line screen), the SID synthesizer chip (versus the VIC's
tone generator), multicolor sprite graphics (not found on the VIC), and
a different memory layout. The operating systems of the two computers
also are not the same.
The same
principles hold true for the new Commodore Plus/4 and 16. Neither of
these computers is compatible with VIC and 64 software, except for very
simple programs written in generic BASIC. However, the Plus/4 and 16
are generally compatible with each other, assuming the program is
written to fit in the 16K RAM found in the Commodore 16.