Re: Help with 41CV - memory problem ?
Message #7 Posted by Eric Smith on 7 Sept 2011, 8:55 p.m.,
in response to message #6 by timw
You are correct that 1LE701 contains the first 64 "user" memory registers. The "000 REG 46" is the correct display after entry to PRGM mode from MEMORY LOST, because the partition between registers registers and program space is fixed somewhere in the middle of the 1LE701 chip.
With all RAM chips installed, you should be able to access (STO and RCL) registers 00 though 272, but you have to use indirect addressing to get at registers above 99. For instance, you could do something like:
272 STO 00
1.23456789E41 STO IND 00
CLx
RCL IND 00
and you should bet the stored number back. (Press the gold shift key for IND.)
The other ways to look at the memory size are:
XEQ alpha SIZE alpha 000 -- configures for NO user data registers
PRGM - tells you how many program registers are available, e.g.,
00 REG 63, 00 REG 127, 00 REG 191, 00 REG 255, or 00 REG 319
Or, with the Extended Function/Memory module:
XEQ alpha SIZE? alpha
Failing during PACKING suggests that there is another failure. Most likely this would be either a ROM, the 1LA701 RAM, or the processor chip (1LA5-0001, 1LE3-0002, or 1LF5-0002). It is obvious that the ROMs, 1LA701, and processor are at least partially working, which makes this difficult to pin down.
The official service procedures would tell you to replace a series of chips until the calculator works correctly. This is obviously not practical for you, since there is no source of replacement parts aside from other calculators. At this point it sounds to me like your 41CV is only useful as a possible parts donor.
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