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Sharp PC-1251 memory upgrade
06-14-2014, 10:12 PM
Post: #1
Sharp PC-1251 memory upgrade
Hi, is there anybody who did the memory upgrade of the Sharp PC-1251?
I own the gadget and recently found an article
http://edgar-pue.tripod.com/sharp/pc1251.html
where Adam describes how he extended the ram from 3.5kB to ~18kB. The 3.5kB is a fair amount, but 18kB would be great to have. HW-wise it is not difficult, but I would be happy to hear about a success from more sources, before I start to mess with internals of my lovely calculator Smile
Thanks.
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06-15-2014, 08:57 AM
Post: #2
RE: Sharp PC-1251 memory upgrade
(06-14-2014 10:12 PM)pito Wrote:  Hi, is there anybody who did the memory upgrade of the Sharp PC-1251?
I own the gadget and recently found an article
http://edgar-pue.tripod.com/sharp/pc1251.html
where Adam describes how he extended the ram from 3.5kB to ~18kB. The 3.5kB is a fair amount, but 18kB would be great to have. HW-wise it is not difficult, but I would be happy to hear about a success from more sources, before I start to mess with internals of my lovely calculator Smile
Thanks.
I don't see a problem if you just properly replace the second RAM chip with a 32K SRAM and trim the plastic as is described in the latest mail on the page. I haven't tested the mod myself, though.

Marcus von Cube
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06-15-2014, 01:27 PM (This post was last modified: 06-15-2014 01:38 PM by pito.)
Post: #3
RE: Sharp PC-1251 memory upgrade
(06-15-2014 08:57 AM)Marcus von Cube Wrote:  I haven't tested the mod myself, though.
I cannot find the Service manual for 1251 (or for TRS-80 PC-3, 1250, 1255, maybe 1260/61).. The Adam's description may work, but a double check would be fine to make..
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