4 Jul
2003
4 Jul
'03
9:09 a.m.
--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote:
Ah... they must have been recycling old 6530s rather than making
new ones. That's handy to know (I have a few DOS 1 6530s from
Yes. I've looked at the schematics and 6530 data sheet, and it's certain
It
suggests that the "fragile" part is a 6530 - a part made by
Commodore that was always customized for its particular application...
Mine has that, but I thought the chips on the daughtercard were a 6530
(from which the ROM section is not used, so any 6530 should work), and a
ROM. Oh, and maybe a bit of glue logic. from the former that the chip is a 6530. The ROM is not
used (RSO is tied
high). Instead, there's a 2716 EPROM, with a 74LS04 inverter
to sort the
chip select out.
Looking at the data sheet, it appears that certain other things were
mask-selectable, not just the ROM code. Things like whether certain pins
were port lines or chip selects. So I guess not _all_ 6530s will work.
But I think all 6530s from CBM drives will.
-tony