1 Feb
2002
1 Feb
'02
2:17 a.m.
-----Original Message-----
From: Ben Franchuk [mailto:bfranchuk@jetnet.ab.ca]
Remember that
it takes a relatively old OS to boot a 512k mac.
I still remember reading how to
upgrade your mac to 512k from
128k. The
old solder on new chips over the old ones trick. 
1 Feb
1 Feb
2:16 a.m.
On Fri, 2002-02-01 at 11:17, Christopher Smith wrote:
I recall the same kind of trick for a color-computer 1. :) In
that case, it was supposed to give you extra capacity above the
supposed 64k maximum. No idea how it was addressed. It could
be that my memory is cloudy and it was an upgrade _to_ the 64k
maximum.
Partly cloudy. My dad did the 32K->64K upgrade on the coco1, and it
required the 2nd bank of 32K to be soldered on top of the 1st bank :)
With some motherboard trace cuts thrown in for good measure.
-----Original
Message-----
From: Ben Franchuk [mailto:bfranchuk@jetnet.ab.ca]
Remember
that it takes a relatively old OS to boot a 512k mac.
I still remember reading how
to upgrade your mac to 512k from
128k. The
old solder on new chips over the old ones trick. I seem to remember, for some reason, the upgrade got
the thing
up to 96k or some odd number like that.
Of course, this is a vague recollection from an article in a "Hot
CoCo" magazine a while back, so may not be completely accurate.
Or it may be way off. The only part that I recall with clarity
is that one was required to solder new chips on top of the old.
Though it wouldn't surprise me if that was also a project. For a
project in one of my CS classes here at IU, I expanded a 6800 SBC to
320K. hehe, 4k bank switching ;)
Brian
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl
Hacker.")."\x08!\n");
'
4:14 a.m.
On 1 Feb 2002, Brian Wheeler wrote:
Can you tell us the part number for a 32K RAM?
(Rhetorical question - TANSA)
The original Coc was 16K; getting THAT up to 32K could be done by
piggybacking, or by putting in 64K chips with some minor trace cutting and
jumpering.
Going from 32K to 64K requires reconfiguring the hardware to see the rest
of the RAM in the "32K" chip that was actually a 64K, and sometimes
required replacing the 16K (or double 16K) chips with 64K ones. Some
people reported running into some 64K chips that RS was using as 32K that
may have been defective and had to be replaced to access the full 64K.
I let Dr. Marty do the upgrade on my early Coco. He was always overjoyed
to have an audience when he worked.
He also hooked up the BNC for me for composite video.
> old
solder on new chips over the old ones trick.
Partly cloudy. My dad did the
32K->64K upgrade on the coco1, and it
required the 2nd bank of 32K to be soldered on top of the 1st bank :)
With some motherboard trace cuts thrown in for good measure.
4:15 a.m.
On Fri, 2002-02-01 at 13:14, Fred Cisin (XenoSoft) wrote:
On 1 Feb 2002, Brian Wheeler wrote:
Can you tell us the part number for a 32K RAM?
(Rhetorical question - TANSA)
Been way too long ago...I was just excited to get Extended Color Basic
for my birthday :)
> old
solder on new chips over the old ones trick.
Partly cloudy. My dad did the
32K->64K upgrade on the coco1, and it
required the 2nd bank of 32K to be soldered on top of the 1st bank :)
With some motherboard trace cuts thrown in for good measure. The original Coc was 16K; getting THAT up to 32K could
be done by
piggybacking, or by putting in 64K chips with some minor trace cutting and
jumpering.
Going from 32K to 64K requires reconfiguring the hardware to see the rest
of the RAM in the "32K" chip that was actually a 64K, and sometimes
required replacing the 16K (or double 16K) chips with 64K ones. Some
people reported running into some 64K chips that RS was using as 32K that
may have been defective and had to be replaced to access the full 64K.
Hey, I think the fog is clearing. Seems we had the 4K model, which was
upgraded to 16K shortly after we got it. I got extended color basic for
my birthday, which required 32k, so we must have done the stack with
that. Later we had memory problems and moved to 64K...which would
explain why I'm having flashbacks of 8 (or 9) piggyback chips with some
extra leads between them sitting on a shelf in my dad's workroom, since
he never throws anything away.
I'm going to check around home, seems I remember coming across the
instructions for the upgrade somewhere...
Brian
I let Dr. Marty do the upgrade on my early Coco. He was always overjoyed
to have an audience when he worked.
He also hooked up the BNC for me for composite video.
5:59 a.m.
On 1 Feb 2002, Brian Wheeler wrote:
You're right! It has been a LONG time.
But if anybody really wants, Doctor Marty would gladly talk for days about
the details from his own faulty memories.
> Partly
cloudy. My dad did the 32K->64K upgrade on the coco1, and it
Been way too long
ago...I was just excited to get Extended Color Basic
for my birthday :) 
6:47 a.m.
Brian Wheeler wrote:
Hey, I think the fog is clearing. Seems we had the 4K model, which was
upgraded to 16K shortly after we got it. I got extended color basic for
my birthday, which required 32k, so we must have done the stack with
that. Later we had memory problems and moved to 64K...which would
explain why I'm having flashbacks of 8 (or 9) piggyback chips with some
extra leads between them sitting on a shelf in my dad's workroom, since
he never throws anything away.
I'm going to check around home, seems I remember coming across the
instructions for the upgrade somewhere...
If I remember right the coco 3 also required piggybacking rams too since
the real upgrading required chips that where very pricey and hard to
find.The few coco 3 hackers left are adding IDE drives and several megs
of memory.
--
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html
10:56 a.m.
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-
ard＠p850ug1.demon.co.uk -
bdwheele＠indiana.edu -
bfranchuk＠jetnet.ab.ca -
cisin＠xenosoft.com -
csmith＠amdocs.com