How to install Extended Memory System on
the calculator, that is missing here - usefull for fx7700
GE/GH
Requirements :
-
calculator supporting send/ reveive backup of RAM and array support (A[3]
must work)
-
cable
-
RS232 - Jack 2.5 mm interface (or other CASIO<->PC interface)
-
Software allowing you to send & receive backup of RAM in .cas or .cat
format
How to do it:
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Reset your calculator
-
Send backup to PC and save it as backup1
-
Execute Defm 1
-
Send backup to PC and save it as backup2
-
Skip to 9. if you have backups in .cat format
-
Compare the both backups - somewhere in the beginning of the file should
be difference - backup1 should contain bytes 00 00 where backup2 contains
01 00 (or 00 01, I am not sure which endian is used). Rewrite these bytes
(in backup1.cas) to FF FF (use hex editor, for example Volkov commander build-in
editor)
-
Recompute the checksum - add 2 (modulo 256) to the last byte of
backup1.cas
-
Skip to 10.
-
Compare the both backups - somewhere in the beginning of the file should
be difference - backup1 should contain string " 00 00 " where backup2 contains
" 00 01 " ( or "01 00" , I am not sure which endian is used). Rewrite
this string (in backup1.cat) to" FF FF "(use notepad or other text editor
without formatting)
-
Rename backup1 to EMS and send it to your calculator, if happens error somewhere
(receive error or memories are not accessible (A[-9999] .. Z[9999] should
work)) try it once more. If you cannot do it successfully after a few tries,
contact me, but it's possible, that this heuristic method is not applyable
in your case.
I didn't test this method, but it should work on fx7700 GE/GH, fx 9700 GE/GH,
cfx 9800 G, but on the 9xxx calculators is the EMS unusable, because the
variables are complex, so the length varies (10 or 20 bytes)
You can theoretically use it on fx7700GB too, but you must use special lx387
Transmission to send / receive RAM backup; to do it you must have EMS installed
:-)))