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HP Forum Archive 15

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Diagnostic ROM for 71B
Message #1 Posted by kim on 18 May 2005, 4:41 a.m.

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

1234

      
Re: Diagnostic ROM for 71B
Message #2 Posted by Gordon Dyer on 20 May 2005, 5:07 p.m.,
in response to message #1 by kim

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

            
Re: Diagnostic ROM for 71B
Message #3 Posted by kim on 20 May 2005, 6:03 p.m.,
in response to message #2 by Gordon Dyer

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

                  
Re: Diagnostic ROM for 71B
Message #4 Posted by Jan Buitenhuis on 31 May 2005, 7:52 p.m.,
in response to message #3 by kim

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

                        
Re: Diagnostic ROM for 71B
Message #5 Posted by Eric Smith on 1 June 2005, 12:12 a.m.,
in response to message #4 by Jan Buitenhuis

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

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.

                              
Re: Diagnostic ROM for 71B
Message #6 Posted by Jan Buitenhuis on 1 June 2005, 7:00 a.m.,
in response to message #5 by Eric Smith

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

                                    
Re: Diagnostic ROM for 71B
Message #7 Posted by J-F Garnier on 2 June 2005, 3:45 p.m.,
in response to message #6 by Jan Buitenhuis

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.

                                          
Re: Diagnostic ROM for 71B
Message #8 Posted by Jan Buitenhuis on 2 June 2005, 5:42 p.m.,
in response to message #7 by J-F Garnier

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

                                          
Re: Diagnostic ROM for 71B
Message #9 Posted by Eric Smith on 3 June 2005, 10:20 p.m.,
in response to message #7 by J-F Garnier

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

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

Quote:
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,

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.

Quote:
and you may not sure that all addresses are fetched.

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

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

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.


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