HP Forum Archive 10

[ Return to Index | Top of Index ]

Downloading ROM functions Message #1 Posted by Steve on 3 Feb 2003, 9:32 p.m. Is there any way to download (copy) a ROM function or an entire catalog (not a program) into memory? The COPY command only works for programs. My reason for doing this is to be able to copy programs from one 41cx to another 41cx. I have 2 HP/ILs but only one Extended IO ROM (I can't afford 2!). I figured if I could make a copy of the X IO in memory (INP, OUTP) then I could make it work. Is there any other way? Thanks, Steve

Re: Downloading ROM functions Message #2 Posted by Vieira, Luiz C. (Brazil) on 3 Feb 2003, 10:04 p.m., in response to message #1 by Steve Hi; there is a way to generate ROM images from existing ROM modules, but it needs specific hardware (other ROM modules) that allow it to be done. These ROM modules (if I am not wrong the CCD and the PPC ROM's allow this sort of procedure) are somewhat hard to find. Even so, if you have the ROM image, I cannot figure a way out to use it internally unless you build a ROM module with that image, say, you will even need the external HW to accomodate the ROM data you have already downloaded. There is no available hardware inside the HP41CX to hold this data, and I believe the 2233 bytes will not be enough to hold all of the I/O programs. Even if you do it, there will be no room for anything else, right? If you store the ROM image in the X-Memory there it will be necessary to find a way to use the X-Memory contents directly. I know that some synthetic maneuvers allow a program stored in X-Memory to be ran without copying it to RAM. I tried it once and it worked fine, but the XEQ instructions generated NONEXISTENT error, so I simply did not try again. But this works with programs, I do not even know how to store a ROM image in the X-Memory space. All of this is based in some experiences of mine and some posts in here. But I am almost sure it cannot be done witn the unique HP41CX available hardware. Hope you have other, better news. Success.

Re: Downloading ROM functions Message #3 Posted by Håkan Thörngren on 4 Feb 2003, 2:32 a.m., in response to message #1 by Steve If I interpret this correctly, you want to save a ROM image into RAM and then transfer it to another HP41? I do not understand why you want to do this? I mean, why transfer it via HP-IL, isn't it much easier to just plug the module into the other HP41 and COPY the programs you want to have in memory? To do something meaningful with (even extract) a raw ROM image requires an MLDL (special hardware).

Re: Downloading ROM functions Message #4 Posted by Vieira, Luiz C. (Brazil) on 4 Feb 2003, 4:17 a.m., in response to message #3 by Håkan Thörngren Hi; it seems to me Steve wants a working copy of a ROM with functions, not programs. He mentions the X-I/O module. At least, that's what I understood. Cheers.

Re: Downloading ROM functions Message #5 Posted by Daniel Diggelmann on 4 Feb 2003, 6:06 a.m., in response to message #4 by Vieira, Luiz C. (Brazil) A download of machine code written ROM functions into USER RAM isn't possible as USER RAM is 8 bits wide whereas ROM modules are 10 bits (quite special isn't it?) wide. Only USER CODE programs can be transferred from ROM into USER RAM. You would require a RAMBOX (W&W / ERAMCO ...) to do this. Another idea is to do it by using the new EMU41 and a HPIL PC card which emulates exactly a HP41. I find this an interesting way to experiment with HP41 stuff.

Re: Downloading ROM functions Message #6 Posted by Steve on 4 Feb 2003, 9:16 a.m., in response to message #1 by Steve My goal is to transfer programs (user written) from one 41cx to another 41cx over HP/IL. That's why I need 2 X-IO ROMs (which I don't have, and can't afford since they are about $200 on eBay). Maybe there is a better way to transfer programs between 2 41cx's? I know I can do it indirectly by using the rs-232 interface and using a PC. This is the most logical approach since I will want a PC copy of the program anyway for safe keeping. This is great unless I just need to copy from cx to cx quickly. Thanks, Steve

Re: Downloading ROM functions Message #7 Posted by Johnny Billquist on 4 Feb 2003, 9:23 a.m., in response to message #6 by Steve Well. The most common way, back in the old days, was to use magnetic cards. Another option is to store the programs/data on tape, using HPIL.

[ Return to Index | Top of Index ]

Go back to the main exhibit hall