Message from discussion semi-ot: motorola 6847
Received: by 10.68.234.38 with SMTP id ub6mr8447219pbc.2.1338740746072;
Sun, 03 Jun 2012 09:25:46 -0700 (PDT)
From: glen herrmannsfeldt <g...@ugcs.caltech.edu>
Subject: Re: semi-ot: motorola 6847
Date: Sun, 3 Jun 2012 16:25:41 +0000 (UTC)
Organization: Aioe.org NNTP Server
References: <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org>
User-Agent: tin/1.9.6-20100522 ("Lochruan") (UNIX) (Linux/2.6.32-5-amd64 (x86_64))
X-Notice: Filtered by postfilter v. 0.8.2
Roger Ivie <ri...@ridgenet.net> wrote:
> On 2012-06-03, glen herrmannsfeldt <g...@ugcs.caltech.edu> wrote:
>> The 6847 was the basis for the TRS-80 color computer.
> The color computer and similar Dragon machines were pretty much
> right out of a Motorola app note for the 6883. I used to have
> a copy of the app note; not sure how easy it is to find these days.
I think I still have the CC service manual. I will have to
dig it out.
>> That, and the 6883 along with the 6809 were pretty much used
>> as designed by Motorola. I believe the 6847 works without the
>> 6883, but I am not completely sure about that.
> IIRC, the 6847 is close enough to pin-compatible with the 6845
> that people used it as a drop-in replacement.
When I first got my CC, I ordered the data sheets for the chips,
plus the 6845. I didn't remember them as being that close, but maybe.
The 6845 is more general purpose, though. All the timing is
programmable, where the 6847 has specific video modes.