|Re: HP41 navigation module question|
Message #13 Posted by Dan Grelinger on 9 July 2008, 11:27 p.m.,
in response to message #1 by Muhammad Ahmad
I got out my module and here is what I can share:
The part number on my module is HP 00041 - 14028. Made in Singapore. "Navigation" is printed on the end. The serial number is 8726 (26th week of 1987). When I do a CAT 2, the header function is "NAVIG 1B". There are 61 entries in the catalog (besides the header) consisting of all user code programs, no machine code functions.
Flag 21 should have no effect on this problem, having it set versus clear will not normally cause a "NONEXISTENT" error.
Insufficient register allocation could, but if you have at least a size of 54, there is not a problem there. (By the way Randy, if you do a "SIZE 054", and then "STO 54", you will get a 'NONEXISTENT' error. The correct test is "STO 53". You forgot about register 00. ;-) )
In my module, there is a "JD" program, but there is no "JT" program, and I don't see one mentioned in the manual. If your module shows a "JT" program, that is definitely a problem.
There is a "*SRT" program in the module (or there is in mine, and it is supposed to be there in every module).
There is also an "SRT" program. An interesting thing that you can look at is; the Label "SRT" is line 001 of the program that it is in. Label "*SRT" is in line 017 of that same program. And line 10 of that program (where you have "10 T Jc?" is supposed to be "10 THc=" or more appropriately "'Hc=", where the T or the ' is the small text symbol that is elevated, and signifies a text entry line for the HP-41.
And in answer to your question about how the ROM data is transferred to the HP-41: The HP-41 ROM 'byte', or more appropriately 'word', is 10 bits long, not 8. And yes, a look at the connector count between the calculator and the module would indicate that the data is clocked out serially from tne module to the processor of the calculator. User code program instructions are limited to 8 bits, the extra two go essentially unused. But the HP-41 processor uses a 10 bit instruction set, and uses all 10 bits of the ROM word to store M-Code (micro-code) which is the progamming language used for the calculator functions.
Bottom line: unless your HP-41 has a serious problem (I would not rule that out without testing the Navigation module in a second HP-41) your Navigation module is hosed; irreversibly. I hope that you did not just buy this from someone else.
Edited: 9 July 2008, 11:30 p.m.