Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!van-bc!
From: lphillips@lpami.wimsey.bc.ca (Larry Phillips)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Developer boards
Message-ID: <2251@lpami.wimsey.bc.ca>
Date: 19 Nov 90 19:32:48 GMT
Lines: 49
Return-Path: <lpami!lphillips>
To: van-bc!rnews

In <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.  

IVS had a prototyping board that included autoconfig logic, but I don't know if
they still do or not. I didn't get one because they would not release any
information about their circuit or PAL equations. This made it (to me) totally
worthless, since modifications to fit whatever I wanted to do would have taken
a fair bit of time with a logic analyzer to figure out. Oh well.

>    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.

I'm afraid there isn't much else to do but to figure it all out. Basically, the
PALs provide two necessary things, one being timing signals for the Zorro bus,
and the other being actual config information. If you don't have a PAL burner,
you can generate timing signals in the traditional manner (gates, flipflops,
etc.), and put the autoconfig information in a ROM. It takes a little figuring,
but it isn't all that difficult.

The other alternative, of course, is to have PALs burned for you, with your
modifications included, if appropriate.

-larry

--
The only things to survive a nuclear war will be cockroaches and IBM PCs.
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|   //   Larry Phillips                                                 |
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