M H Stein
dm561 at torfree.net
Fri Feb 15 03:15:42 CST 2008
Date: Fri, 15 Feb 2008 02:57:08 -0500
From: "Roy J. Tellason" <rtellason at verizon.net>
Subject: Re: EPROM programmer
On Friday 15 February 2008 01:46, Ethan Dicks wrote:
> 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...
No, it doesn't. It's just a minor annoyance, which is probably why I only
gripe about it every now and then nad hvaen't really gotten around to doing
anything about it... :-)
The manual has pretty clear instructions for changing the baud rate, up to 19.2
(pp. 8&9); you'll need 2x27128 unless you have a second programmer.
> > 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.
Hmm. I wasn't thinking PET as much as C64, when I wrote that. The ROMs in
that one were all 24-pin parts, a 4K character rom and the BASIC and Kernal
being 8K, which would need a 2764.
See MCM68764 & MCM68766 (24 pin 8Kx8)
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