HP-41 Memory & Interfacing Message #1 Posted by Diego Diaz on 12 May 2003, 1:28 a.m.
I had previously posted that message on late April, anyhow it was the last in the thread, and probably remains unseen (or -simply- no-one was willing to answer...:-(
Ok, just kidding...
<<Hi everybody,
It seems that the customized EPROM modules issue still have a lot of interest in this forum (easy to understand when looking at e-Bay prices :-)...
Let me see if I've understood the previous message...
- Are there EPROM chips (those UV erasable) that fit into a standar HP-41 module case??
- If the answer is YES, are there any clue about which modules could carry this (almost magic) chip?
- AFAIK, ROM modules are 10bit/word and RAM modules are 8bit/word... Anyhow, some modules share machine-code and user code programs in the same device, Does someone knows how they overcome the word lenght difference?
- Is it possible to place a small Lithium battery inside a, said, Quad-Ram module to turn it into a pseudo ROM?
... Well, I'm abusing I know, but those questions have been prowling into my head for long, since I'm a "harware guy" (those with the soldering iron and tweezers), sometimes messing my brain up, and you seem to be the only good answers source.
Thanks in advance and best whishes from the Canary Islands.
P.S. Please forgive my grammar "crimes".>>
Some MLDL related threads have born since I wrote this, and superb Meindert's work seems to flood some ligth inside my smoogy neurons, anyhow the question of the 10bit/word EPROM chips and M-code/U-code sharing remains somewhat obscure.
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