Diagnostic ROM for 71B

[Kim]

Hello all fellow 71 enthusiasts

I have found myself a decent photocopy of the manual for the 71B Diagnostic ROM and I was wondering if anyone have a image of the ROM itself.

KimH

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[Gordon Dyer]

Hi, I don't have the ROM but I would like a copy of the manual if you can get it scanned.

[Kim]

I am planning to run it through my PDF scanner at work in the next couple of weeks and upload it to Dave's site-CD-DVD

I'll send you a copy (remind me if I forget)

Kim

[Jan Buitenhuis]

Hallo Kim,
I do have the HP Diagnostic Rom for the HP-71B, however I don't think you can make an image of it. The module most be inserted in port 1 and it autostarts the HP-71B and takes over the machine. It does internal checks and then you can manually check several features of the machine (like keyboard, roms, etc). If anyone can tell me how to make a image of this ROM I will gladly distributed them (provided HP is not killing me).
Regards Jan Buitenhuis

[Eric Smith]

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If anyone can tell me how to make a image of this ROM I will gladly distributed them (provided HP is not killing me).

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AFAIK, the easiest way to dump it is to hook up a logic
analyzer to the Saturn bus (possibly via the card reader
connector, which is easy to clip probes onto), and
capture all the bus cycles that occur when the diagnostic
ROM tests itself.

I have the equipment to do this, and I have a 71B, but I don't have a diagnostic ROM to dump.

[Jan Buitenhuis]

Hallo Eric,
I don't have the equipment and/or knowledge to do this so the only possibility to "dump" the diagnostic rom would be to send you my module. However I definately want it back afterwards. Can you email me so that we can make arrangements?
Regards Jan Buitenhuis

[J-F Garnier]

Hi Jan and Eric,

The Diagnostic ROM may be a true take-over ROM, as the port 1 includes the OD signal to disable the internal ROMs.

Using a logic analyzer to the Saturn bus will not be so easy, because you will have to disassemble the bus commands to decode address and so on, and you may not sure that all addresses are fetched.

An other way would be to use a small assembly language routine running in RAM to copy the content into a 32k independant RAM.

J-F

P.S. added: Finally I don't think that this ROM uses the OD feature, because it would be usable to check the internal ROM...

Edited: 2 June 2005, 4:09 p.m.

[Jan Buitenhuis]

Hallo Jean-Francois,
After I get the diagnostic ROM back from Eric I can send it to you so you can have a go at it, if Eric does not succeed.
Or if he can make an image I can try to burn it in an CMT EPROM for you. Keep in touch,
Regards Jan

[Eric Smith]

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The Diagnostic ROM may be a true take-over ROM, as the port 1 includes the OD signal to disable the internal ROMs.

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The HP-71B Service Manual states that the diagnostic ROM must be used in port 1.

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Using a logic analyzer to the Saturn bus will not be so easy, because you will have to disassemble the bus commands to decode address and so on,

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Not a problem. I've written program to decode logic analyzer traces from other HP calculators, as well as from many other things. I also recently needed to be able to use a waveform viewer for logic analyzer dumps. There's a standard digital waveform file format, VCD ("Value Change Dump"), so I wrote la2vcd to convert the files from my HP 16500B.

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and you may not sure that all addresses are fetched.

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If it's like other HP diagnostic ROMs, it will have the
ability to check itself, by computing a checksum.

Quote:

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An other way would be to use a small assembly language routine running in RAM to copy the content into a 32k independant RAM.

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That's been suggested. But if I'm not mistaken, as soon as you try to plug in the diagnostic module, you'll get a non-maskable "module pulled" interrupt, and the vector is in the ROM.