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Found these inside a non-working 71B
03-11-2018, 08:15 PM
Post: #30
RE: Found these inside a non-working 71B
(03-11-2018 07:53 PM)MikeSD Wrote:  I think i will test these chips in another 71b thats known working. Math, FORTH and 64K RAM would be a good find, in a calc i marked junk a few years when it didnt work when I turned it on, assuming they are working.

Keep in mind the FORTH ROM Module actually contained 2 ROMs; one is fixed address at 0xE0000 and the other is loadable anywhere, placed at the 'right' address by the OS' config routines.

Perhaps the board with the very different layout is a board that holds the 32KB ROM that is fixed at 0xE0000 ? Makes sense that it would have fewer leads, I think...

--Bob Prosperi
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RE: Found these inside a non-working 71B - rprosperi - 03-11-2018 08:15 PM
What's U10? - Dave Frederickson - 03-15-2018, 03:43 PM

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