Disassembling 12k ROM on HP-41


How would I check if a module that I have is a 12k module and how would I go about disassembling it. If I put my module into slot #4 with NoVRAM in #1 I could DISASM E000-EFFF and F000-FFFF but what about the third 4k bank. I suspect that it is 12k module since in the listing of the first bank I have seen several ENBAK 3 commands.

I am using TRANS41 to capture the listing.




the ENBANK3 opcodes don't automatically mean there's a third page, they could simply be data, or part of an instruction.

Regarding disassembling bank switched ROMs, I think the HEPAX manual talks about this topic.

Which ROM are you talking about?

Maybe a query of Matthias' module list (at www.hp-collection.org) could answer some questions .



You have to find a way to enable that second bank _before_ disassembling it. IIRC the secondary banks may be enabled/disabled idependently, as such you may *not* call the switch routine of the HP-41CX in page 5 to switch the secondary page of the Advantage Module for example. You have to find the switch routine of your module. Be careful, as Raymond remarked, the ENBANK 3 in your disassembly may be wrong interpreted by your disassembler.



A common mistake is FOCAL programs being "disassembled", generating lots of ENBK3 mnemonics but obviously not being such.

The HEPAX function "HEXEDIT" (included in your NoVRAM) can switch between banks, just press the "+" and "-" keys as requested. The appropriate flag indicator (1-4) will also come up to let you know which bank it's looking at.(Unfortunately this function is "disabled" for itself, so you wan't see the HEPAX ROM contents).

A couple of examples are the IR_Printer module, and of course the Advantage.

You can also use the nice MCODE program posted in T.O.S.



Thanks for your answers. You were all right that ENBANK3 was actually not enabling the third (nonexistent bank). The module in question is INFOH1 module made by Flopetrol Schlumberger (my former employer) and was intended for surface flow measurements calculations of oil wells with some unit conversions etc.

I got the module as a loaner from a colleague from UK (after several months of trying) and was downloading its content. I finally succeeded late last nite and as Angel guessed the module is just a bunch of FOCAL code in 8k module. I disassembled the first page and I saw several ENBANKS there so I figured I better ask. After that NoVram-IL-TARNS41 was giving me some trouble so the disassembly was not smooth (I had to reburn NoVRAM few times) but finally succeeded and the images run on Clonix, EMU41 and V41. Now the problem will be to convince Schlumbeger to allow publishing it.


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