Re: PET keyboard models

From: Ethan Dicks <>
Date: Sun, 15 Aug 2010 22:45:52 -0400
Message-ID: <>
On 8/8/10, MikeS <> wrote:
> Actually Ethan Dicks might know more about it than I; last I heard he had
> Phil Lord's (?) original PET board from Japan for repairs.
> IIRC the CG ROM was not an original CBM ROM, but an EPROM in an adapter...

Close, but not exactly.  It's a CBM 2316 mask-programmed ROM in a
professional-appearing PCB adapter (solder mask, etc).  The IC is in a
white-ceramic-and-gold package, but the lid is bare steel and came to
me quite spotted with rust.  The best I can make the number out is
901447-12  The adapter is marked "2316E PCB ADPTR" and "P/N 320076".

Unfortunately, the ROM reads all zeros in a 6540 socket and the
characters "displayed" are blank or all-on (normal vs reverse-video),
but that's to be expected since reverse-video is done in hardware on

> and
> in fact one of the problems with that PET was with the CG ROM, so we had to
> recreate it.

Yes.  The recreation does seem to match the keyboards I've seen, but
I'd love to see some software that depends on the precise character
arrangement.  The only Japanese software I've seen for the PET used
block graphics to draw Kanji and/or Katakana characters ("MUGYU!" was
one, IIRC).

> AFAIK the Exxx editor ROM was the standard one though.

Yes.  The other ROMs were entirely ordinary (and already on

> I'll post some pics when I get back home; I think Ethan hangs out here,
> maybe he can add some info.

I do hang out here, but I've been on holiday for most of the past
couple of weeks.  I just got back tonight.


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Received on 2010-08-16 03:00:09

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