Mind you, if
someone offered me a 64 or a 128, I would choose the 128, if
that helps you make up your mind. I don't have a C64 on my desk; I have a
128DCR, and I run all of my 64 software on it, plus all the added features
of being a 128 (true 80-column 640x400 graphics with a CGA monitor; fast
serial transfers; 16-64K of additional VRAM which can be accessed from 64
mode as "cache"; and 2MHz mode). Really, the 128 is a very worthy
successor to the 64.
How much effort is the VRAM hack? What is involved?
It's fairly easy. The VDC registers still show up in 64 mode due to an
incomplete mapping in the MMU, so you initialize the chip as if you were going
through the 128 startup sequence, and then just store values into its RAM.
I say that it's best used as "cache" because it's pretty slow access;
the
VRAM of the VDC is not memory mapped and must be accessed byte-by-byte through
the registers (like the 9918). Still, this can be a nice amount of space to
stash something for later rather than loading it from disk, and you're
guaranteed to have at least 16K on every 128 (64K on DCRs and upgraded units).
In HyperLink 2.5,
http://www.armory.com/~spectre/cwi/hl/
I use VDC RAM to cache downloaded web pages. It works quite well.
--
--------------------------------- personal:
http://www.armory.com/~spectre/ ---
Cameron Kaiser * Floodgap Systems *
www.floodgap.com * ckaiser at
floodgap.com
-- Po-Ching Lives! ------------------------------------------------------------