HP Forums

I have a "RACETRACK" module for the HP-41 that has left me with three questions.

Q1? It runs programs in the application ROM automatically as soon as the HP-41 is turned on, much like the AUTO/START DUPLICATION rom. How does it run automatically? The rom is marked "RACETRACK" on the end, and on the bottom 82500A-A24", "DR Z INV. INC", "ID 21 USA". The datecode is "8528". Starting sequentially with XROM 21,00 the functions and programs are: XROM'RECOVER, XROM'TWR, XROM'TRPYBK, XROM'WEALTH, XROM'AL, XROM'SHOW, XROM'SHOWD, GETKEY, PSIZE, PASN, XROM'PLACE, XROM'PLACEB

Q2? Running CAT 2 on my HP-41CX, the ROM does not show up in the catalog. Why?

Q3? How did they mix usercode programs like SHOW with machine code functions GETKEY, PASN, and PSIZE (these three functions seem idsentical in operation tho the EXTENDED FUNCTIONS functions by the same names)?

Q3 - in a ROM you can mix user code an m-code programs easily. The header for each says whether it is user or M code, and the calculator interprets it appropriatly.

Q2 - I have one like this. Good question

Q1 - One way is if it is on the autostart page (page 4) but I suspect that there are other ways

If you have access to a zenrom (or an ML Development tool, or....) you can dump the contents of this rom and see what it's up to.