Path: utzoo!utgpu!watserv1!watmath!att!att!linac!uwm.edu!ogicse!intelhf!agora!billsey
From: billsey@agora.uucp (Bill Seymour)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Developer boards
Message-ID: <1990Nov28.211252.23606@agora.uucp>
Date: 28 Nov 90 21:12:52 GMT
References: <2218@lpami.wimsey.bc.ca> <11738@hubcap.clemson.edu>
Organization: Open Communications Forum
Lines: 48

In article <11738@hubcap.clemson.edu> dawill@hubcap.clemson.edu (david williams) writes:
:In article <2218@lpami.wimsey.bc.ca>, lphillips@lpami.wimsey.bc.ca (Larry Phillips) writes:
:: In <45608@eerie.acsu.Buffalo.EDU>, v089pfrb@ubvmsb.cc.buffalo.edu (Jeffrey C Murphy) writes:
:: >Does any know where I might find some empty circuit boards that will 
:: >fit into the A2000's 100 pin slot and also some that will fit into the
:: >CPU slot? If so what is the cost per board?
:: 
:: I got one from NES in Oregon (Bill Seymour should be able to give you the
:: address.. I can't find it). It is a Zorro board with connectors for the IBM
:: slots as well. It cost me about $50.
:: 
:: -larry
:
:    Does anyone manufacture one of these with built-in autoconfig and 
:decode logic?  I used to have one of these (on an older computer) that 
:made prototyping a breeze - just use the existing decode and interface
:logic, and plug in your new stuff.  

	There was a company that made one with one type of autoconfig
design on the board, but I don't know if they're still available or not.

:    On the other hand, how do you build an autoconfig block?  I've read
:the A2000/A500 technical reference manual discussion on this, but I
:don't have a PAL burner.  They give equations for these suckers, which
:leaves me out in the cold.  I suppose I could look at the equations and
:figure out just what is going on, but I don't have that much time.

	You can always substitute a PROM for the PAL. Autoconfig is just
a set of address reads followed by a write. You still have to do the
521/374 thing, but the bulk of the PAL stuff could be put in a small
EPROM easily enough. A PAL is just cheaper... And on our designs, we've
tended to put pretty much the whole thing into a bigger PAL. That's the
main problem I've had with doing a board with autoconfig hardwired in,
you still have to burn a PAL or PROM, and you're much more limited on
what else you can do with that part. I hate to waste any PAL functionality
just because I needed part of it for the autoconfig. :-)

:    Ideas, comments?
:
:     Dave Williams
:        dawill@hubcap.cmemson.edu
:           "Huh?  What?  Could you repeat the question?"

-- 
     -Bill Seymour                                            billsey@agora
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