If you want to translate a schematic from the old TTL SSI/MSI devices to a
programmable device in a dense package, it's much more likely to happen easily
in a CPLD than an FPGA, though people keep telling me that FPGA's provide more
logic at lower cost. I agree that it's more difficult to make it happen in
FPGA, but for a circuit the size of a Multibus-1 or (somewhat smaller) S-100
board, a moderately priced CPLD should get the job done pretty well, though they
used enough one-shots to complicate the job considerably.
With device pin-pitch at 20-25 mils, (actually the metric equivalent) it's
unlikely one will hand wire anything with them. Therefore one's limited to
using PCB mounted parts. Since disposal of PCB-related materials is so costly
these days, it's unlikely one will want to do that at home. What this leaves is
a need for an adapter for some fairly standard-packaged-CPLD and/or FPGA, and
then simply work within the confines of what one can have made up by way of an
adapter from that package to something that one can hand-wire or wire-wrap.
Dick
----- Original Message -----
From: <dmc!njc_at_opal.tseinc.com>
To: <classiccmp_at_classiccmp.org>
Sent: Tuesday, November 20, 2001 11:44 AM
Subject: Re: Radio Shack abandons components
> Ben Franchuk
> >
> >Neil Cherry wrote:
> >> On the other note of piece meal components, I've found that with a lot of
> >> imagination one can take advantage of today's uControllers to build some
> >> of the coolest stuff. Processors cost ~$6, 3 pcbs (~2"x3") $50, add the
> >> components and a single hand built board can cost <$100. PLD's, FPGA, etc.
> >> etc.. Man do we live in interesting times (both good and bad).
> >
>
> >But one problem is that almost all real I/O is handled by hard to
> >find semi-custiom chips - PC motherboards come to mind. Many of the
> >older I/O devices are too slow to be of value. Ben Franchuk.
>
> This is, of course, too true. We can emulate them with the FPGA's but
> you have to understand how they work. I've been doing some creative
> work with alternate parts but I haven't had time to sit down with the
> really powerful chips. So little time so many projects.
>
> --
> Linux Home Automation Neil Cherry ncherry_at_home.net
> http://members.home.net/ncherry (Text only)
> http://linuxha.sourceforge.net/ (SourceForge)
> http://hcs.sourceforge.net/ (HCS II)
>
>
Received on Tue Nov 20 2001 - 13:59:15 GMT