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HP-71 Lockup. Help! - Printable Version

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HP-71 Lockup. Help! - Howard Owen - 04-17-2006

Hello all 71B gurus.

Please forgive the long preamble. The bottom line is I have a corrupted LEX chain due to a ROM image in an IRAM and I don't know how to clear it.

I've been writing a LIF library in Perl. It's been going swimmingly, but I can't copy the 9122 images I create onto floppies with the setup I have. (I can't do that with any 9122 image using Tony's tools, but that's another story.) However, EMU41 likes them just fine, so I've been hosting them with that, and copying the contents file-by-file to a real 9114 using my HP-IL connected 71B. I have (had) a lex loaded that supplies the HP-85 file types I'm currently interested in. (I can copy the HP-85 9121 images just fine. I'm doing this as an exercise in writing LIF) I ran into the peculiarity that the 71 considers "-" in a file name to be an error, thus preventing my copying those files. I was mulling over the fact that at last I had a real reason to write some Saturn assembler, when it occured to me that the JPCROM might offer a solution. I then recalled that I wanted to try loading the ROM image into the RAM of my real 71B. I naively copied the file from JF's site into main RAM. Uh-oh. No keywords work now! I surmised that the lex chain was blown away by the ROM image. I pulled all three of my 4K memory cards and the machine reset. Well, I have backups, of course. But I'm stubborn. (I did a "FREE PORT(5.01)" to pull out 32K of my 64K CMT module as an IRAM. I then copied the JPC ROM image into that.

Corrupted lex chain again. Only this time, pulling modules doesn't help. The data are in an IRAM which survives pulling and replacing the CMT card reader port module. As I wrote this, it occured to me that I could pull the CMT module and two 4K modules, copy a bunch of stuff into the remaining (merged) 4K module, plug everything back in, and pull the 4K module to get a reset. However, that seems like a rather violent and risky procedure. Can anyone suggest a better approach? Is it just capacitive charge keeping the CMT module alive when its pulled, or is there a battery involved?

Thanks for any advice you can offer.


Edited: 17 Apr 2006, 6:13 p.m.

Re: HP-71 Lockup. Help! - Howard Owen - 04-17-2006

Is it just capacitive charge keeping the CMT module alive when its pulled, or is there a battery involved?

There's a battery. 8)

Getting the machine to reset didn't work because the IRAM wasn't effected by MEMORY LOST. The above procedure did the trick, though.