Richard Erlacher
>
>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.
Actually I'm about to attempt to learn hwo to do just that, hand
solder qfp chips to a carrier board with DIP header endings. I have an
eZ80 that I want to brain transplant into a spare HCS II (uses a
Z180). I've checked out Don Lancasters page on how to build your own
smt hot air iron and may attempt it this winter. I'll start by working
on low cost parts and work up from there.
--
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 - 14:48:41 GMT