HP-71 Forth/Assembler ROM fix

[rprosperi]

(12-02-2015 05:58 PM)Dave Frederickson Wrote:  I patched HRDFORTH.BIN prior to loading it into Emu71. Seems to work, no slight-of-FRAM magic necessary. Am I missing something?

Dave

For a real 71B w/FRAM71, you need to do this:

Load the HC ROM image into first F_Block
Change jumpers to move this to E0000
Use the POKE statements JFG provided, or maybe easier with the RAM editor
Issue FRAM71 config to reconfigure E0000 as ROM

Voila...

I found a file from John Baker from around 1986 with 5 patches to the FORTH Assembler that fix these fundamental code-generation bugs, plus some other bugs in how the assembler works (e.g. with more than 100 symbols, the assembler listing will not be generated properly if not in DECIMAL mode, and other similarly obscure stuff). I can post it if anyone is interested.

Back then, patching the assembler was done by adding complex RAM-based patches to the FORTHRAM file, but now that we can patch the HC ROM image, it may be feasible to generate simple patches like these for all 5 issues.