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Full Version: Which HP48 to buy for ROM upload
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I want to use Christoph Giesselink's Emu42 program but I need to extract the ROM image from the 42s. Apparently I need an HP48 and the serial PC cable to do this.

As I never used the 48 before I would like to know the least expensive one to buy for this specific task. I see some 48S for as little as $50 and the GX going for over $200 sometimes. So what model should I buy?

I understand that the 48 is a very powerful machine and probably limiting its use to ROM upload may be seeing as a waste by many (and I apologize for that) but I'm a 41/42 lover and have used those machines daily for almost 30 years... I don't think that will change now :-)


48g+ for upload or free42

Edited: 20 Jan 2009, 12:11 a.m.

Like the Pioneer document describes you need ~70KB of free RAM for a HP42S ROM Upload.

Calculator which are fulfill this are

  • HP48G+
  • HP48GX
  • HP48SX with merged 128KB RAM card

The problem is that the HP48G+ is quite rare so it's often cost more or the same as the HP48GX. IMHO early HP48GX manufactured in Singapore with ROM rev. R are worth to buy. Some people swear on the latest ones with the black display from the HP49G. But I think most agree with me that the one manufactured in Indonesia are the worst one.

When you aren't a fan like me, buying a HP48 from the S series isn't such a good idea. Most software written in SystemRPL in the last years don't work on a HP48S(X) any more. Because I use an emulated HP48SX for my daily work, I take care that I write software working on the S and G series, but that's definitely an exception.

But back to your problem, some like you had the same problem only having a HP48 calculator with 32KB RAM. Two years ago I decided to publish a modified Clamshel.txt file describing also uploading a HP28 ROM image in parts to a HP48.

For the Pioneers it's much more difficult, but nevertheless, I wrote such a document describing a Pioneer ROM image upload in parts in January last year. But I wanted to avoid any questions to this complex process, so I decided not to publish this document. I you still want to try it, download the latest version of the CPROMUPL.ZIP package and drop me a mail over MoHPC for request the latest Pioneer upload document.



Thank you all for the great input!!