From: gary@bilbo.inmos.co.uk (Gary Morton)
Subject: Re: GAL Programming revisited
Reply-To: gary@inmos.co.uk (Gary Morton)
Organization: INMOS Limited, Bristol, UK.
Date: Wed, 12 Aug 1992 18:18:43 GMT

In article <1992Aug10.203557.15175@cc.gatech.edu> byron@cc.gatech.edu writes:
>Armed with the April and May issues of Elector Electronics, I am poised to
>build a GAL programmer. However before I start I wanted to get some more
>info. I believe that the answers to these questions may benefit other
>folk so posting is best.
>
>1. Has anyone built the Elector programmer? Did it work?

Yes. I sent an order away to Elektor to buy the PCB and software.
Most of the parts were bought from the local Maplin shop, with the 
exception of the PCB mounted transformer, which I bought by mail order
from Cirkit (like Maplin their mail order magazine is available in
most W.H.Smith newsagents).

Some time ago I had taken up a special offer from National, to buy
their PAL/GAL databook and a small selection of sample PALs and GALs
for about 25 quid.

I first tested the circuit out using a set of batteries (as the transformer
hadn't arrived by then). I was most impressed when the software told me
that I had plugged in a 'National' GAL (and quite delighted that 2 of the
sample parts sent by National were the right type of parts which were 
programmable by the programmer).

As with most of my projects, it awaits being fitted into a box :-) .

>2. Does anyone have FTP'able software that will convert equations to
>   JEDEC files? If not I guess I'll fork over the $20 to get the
>   software that drives the Elector board.

It is well worth buying the Elektor software - it isn't that expensive. Part 
of the software is the interface between the PC and the programmer via the
parallel port, and is very well presented. The other part of the software
is from National (I believe) and has a logic simulator package, and other
useful utilities (one appears to allow you to squeeze a quart into a
pint pot - or rather a small GAL).

>For those of you who are interested I don't plan on using the design as
>given in Elector as given. I have the following changes:
>
>1. Convert the interface from parallel to serial. By doing so I can use the
>programmer on other platforms.
>
>2. I'm going to use a 68HC705k1 as the brains. It'll set the row, shift the
>data, control the programming voltages, and do the serial communications.
>Pretty nifty for a $4 16 pin controller.
>

My advice is to spend your time using the uP to convert from you desired
serial format, into a parallel format the off the shelf Elektor board
expects. While it might be great fun to roll your own programmer, it is
also a lot of effort, and you might well run into difficulties obtaining
all the information you require. Given that someone else has already done
all the hard work, I suggest buying the Elektor design and software. The
time you save will probably cost less than the effort and expense of your
own design. I speak from frustrated experiences of my own :-) .

BTW, I have being meaning to post a review of the Elektor GAL programmer
to the net, once I had got it in its box. There appears to be some
interest in GALs in this newsgroup, so I will do this as soon as I have
a little time to give everything a run through.

--Gary
+---------------------------( Gary Morton )-----------------------------+
|Disclaimer: The opinions above are my own personal views etc.          |
|Inmos Ltd, 1000 Aztec West, Bristol, UK         Email : gary@inmos.com |
+-----------------------( +44 454 616616 X526 )-------------------------+

+---------------------------( Gary Morton )-----------------------------+
|Disclaimer: The opinions above are my own personal views etc.          |
|Inmos Ltd, 1000 Aztec West, Bristol, UK         Email : gary@inmos.com |
+-----------------------( +44 454 616616 X526 )-------------------------+
Newsgroups: sci.electronics