14 Feb
2008
14 Feb
'08
10:46 p.m.
On Fri, Feb 15, 2008 at 01:11:23AM -0500, Roy J. Tellason wrote:
I have the 8052-BASIC based one that Steve Ciarcia had
in an article in Byte,
and that uses a serial connection. Only at 1200 baud, though, for some
reason.
4K doesn't take _that_ long to push over 1200 bps...
Replacing a CBM Kernal ROM is going to need an
adapter, as the eprom has more
pins. Are you into making those or do you know of a source for them?
Depending on which model of CBM you have, there's a no-adapter solution:
for PETs that take 2332 ROMs (i.e., *not* the old Static PETs), the 2532
is a drop-in EPROM. Not the 2732... the 2532. I have a few of them, some
from the old days (with PET firmware on them) and a few
blanks that I've
picked up over the years when I was already ordering from some
place like
B.G. Micro.
I had a $C000 BASIC ROM die in my first PET (the one I got new, when I was
a kid)... there's now a 2532 in its place.
If you can't find any 2532s, you could make a 2732->2532 pin swabber in
a couple layers of machined-pin sockets - the bottom socket goes right
into the PET, the top socket holds the 2732. The middle layer is used
to rearrange whatever pins need relocation. I've had good luck with
stuffing a 1Mbit FLASH ROM into a 32kbit socket that way (and brought out
the extra address pins to a connector to an external switch to be able
to select multiple 4K ROM images). If my description is too vague, I
can try to take a picture to illustrate what I mean.
-ethan>
--
Ethan Dicks, A-333-S Current South Pole Weather at 15-Feb-2008 at 06:40 Z
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Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html