>
>Date: Mon, 07 Jan 2002 12:58:28
>To: John Robertson <jrr(a)flippers.com>
>From: "Fredric L. Rice" <frice(a)skeptictank.org>
>Subject: Re: 9010 compiler
>
>At 11:03 PM 04/01/2002 -0800, you wrote:
>
> >Thanks for releasing that, you'd be surprised how many
> >of us are still using or trying to figure out the use
> >of this great tool. We use ours for checking older video
> >and pinball game logic boards.
>
>That seems to be the industry that's got interest.
>I didn't know that anybody else was using the thing.
>
> >One trick I am trying to solve is how to generate
> >checksums instead of the weird (HP format) signature
> >that Fluke elected to use as their ROM check tool.
> >Have you any thoughts on this or, perhaps, a simple
> >solution.
>
>It's not so simple yet yes, there's a solution.
>You can locate the Z80 code inside of the F9010a
>that generates the CRC. If you locate the
>address of the entry point of the subroutine,
>you could then look for the jump table that
>exists in the machine which is used to vector
>to when CRCs are requested and you can install
>your own routine.
>
>The CRC code is in ROM so you couldn't use my
>compiler to insert a Z80 checksum subroutine on
>top of the Fluke's CRC routine but you _could_
>change the address in the Fluke's jump table to
>point to a _different_ routine that you could
>install into the box using my compiler.
>
>Finding the jump table entry would take time
>since you would need to locate the CRC subroutine,
>note the starting address, and then locate the
>jump table in RAM. Then you can use my compiler
>to create a Z80 checksum routine, then you can
>change the jump table entry to call that routine
>instead of the real CRC.
>
>It's tricky but it can be done.
>
> >I have only just started to read your documentation....
> >perhaps I should just read it closely and get back
> >to you later.
> >Thanks!
>
>No problem! Glad to help.
>
> >Oh, are you familiar with the other compiler for
> >the 9010A? It does some of what yours appears to
> >do, from within a single DOS based program, but the
> >documentation for it was essentially non-existent.
> >I can email you a copy of it if you are curious.
>
>I played with the compiler that Fluke sells and
>was annoyed that it was so simple. There's no
>real difference between what their compiler does
>and what's possible from the keyboard and the
>only real benefit of their compiler is the ability
>to have comments in the code. That's a _BIG_ plus
>since turn-around makes documenting source code
>so valuable.
>
>So I wrote my own and thought I might sell it to
>Fluke. I got back a note telling me that since it
>had no sales research, no product research, and
>wasn't created in house, there was no interest
>in it.
>
> >Ii have a small mail-list for technical tools,
> >that tends to be mostly about the 9010a, called
> >techtoolslist @flippers.com, if you want to join
> >(and be asked a few questions) it's
> >techtoolslist-request@... subject: Subscribe.
> >Again, thanks.
> >John Robertson :-#)#
>
>I'll subscribe, yes. I don't use the F9010a any
>more but if my compiler is going to make the
>rounds, that would be a good forum for answering
>questions and seeing if anybody has bug fixes or
>changes or features they might want.
>
>At the same time I also designed and built a
>TTL chip tester and wrote a library for the 74LS
>series TTL chips that worked with my compiler.
>My device was basically a board with a 40 pin
>socket for the Z80 pod to plug in to, a 4MHZ
>clock source, some bi-directional latches, and
>a zero-insertion-force socket for the TTL chip
>under test.
>
>My device routed the 16 address lines of the
>Z80 pod to every pin of the zero-insertion-force
>socket, isolated by some gates. It also routed
>the 8 data pins to al 16 pins of the zero-
>insertion-force socket. Using my compiler I
>could read and write addresses addresses which
>would drive the inputs to the TTL chip and read
>the outputs of the TTL chip. I wrote software
>that drove counters to count up then read the
>results to give a PASS/FAIL indication on the
>Fluke 9010a.
>
>I have those 74LS programs for my compiler yet I
>suspect I would be hard pressed to find the
>schematic to my TTL tester. If I can find it
>I'll enter it into an ORCAD schematic and I'll
>make it all available.
>
>If you want, you can dump this message into the
>mailing list.
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