Re: 128CR (fwd)

From: Marko Mäkelä (
Date: 2000-01-26 17:05:21

I'm forwarding this message to the list, as the address Ray used did not
work.  (The address is for making "unsubscribe" or "subscribe" requests;
you will receive more instructions if you send the command "help" to that
address or to

The machine sounds really interesting, and there are many open questions,
such as: why two crystals?  Did they maybe try to solve the "vertical
bars in the video output" problem with that arrangement?  But I'll leave
further questions to Nicolas and others.

---------- Forwarded message ----------
Date: Wed, 26 Jan 2000 07:49:56 -0800 (PST)
From: Raymond Carlsen <>
To: Marko Mäkelä <>
Subject: Re: 128CR

On Tue, 25 Jan 2000, [ISO-8859-1] Marko Mäkelä wrote:
> Recently there was some discussion on the cbm-hackers mailing list
> regarding the cost-reduced versions of the Commodore 128 and 128D.  I
> think it was you who once sent me a firmware dump of a 128CR, that is, a
> cost-reduced version of a flat C128.  To save typing, I include a message
> from the mailing list below.
> 	Marko
> Marko Mäkelä wrote:
> > I think I got the 128CR firmware dump from Ray Carlsen.  Maybe I should
> > get back to him to ask if it was a 128DCR board with less components or a
> > truely new design. I'd expect the latter, since I don't think that the
> > 128DCR board would fit in the flat 128 case.

> Yes, and a component list, and I even don't dare to dream of a picture
> of such a board :-)
     The board I have is a flat 128CR. I actually ordered a 128DCR board
from Grapevine before they went belly up and got this one by mistake. Hey,
at least it works! The ROM dump Marko mentioned came from this board, a
C128CR Rev 3 PCB# 252270 PCB Assy# 250783. It is the same size but has a
different layout than the standard 128. Some differences I noticed... On a
paper sticker: "C128CR #2 ENG SAMPLE Jun/9/86 KNT". The RGB chip at U22 is
a 2568R1X instead of the 8563 normally used. It has two 8701 chips (U28 [or
is it U24] and U42) and a second crystal. The two ROMs (both 27256 EPROMS)
at U32 and U34 (U36 empty socket) are in the center of the board (not at
the left end as in standard 128) and the video box is at the left side of
the board. VRAM is 4416 chips and DRAM is 4464 X 4 @ U38 to U41. Other than
the above, the chips appear to be the same as the standard 128. If you need
further info on that board, feel free to email me. Be specific in your
questions, by the way. I'm just a lowly repair tech, not really a hacker.
:) I'm trying to think of the best way to get a photo of this beast. It's
too big for my scanner. ;-)


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