HP Forum Archive 20

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Getting HEXEDIT to work on the HEPAX itself Message #1 Posted by Ángel Martin on 29 Jan 2012, 5:40 a.m. There recently was a thread about getting DISASM to work on the CL, and a related topic was overcoming built-in features in the HEPAX to avoid its own disassembly. here Monte´s instructions solved the riddle for DISASM, but there was still another location checking on the same protection which stopped HEXEDIT to work. To prevent this you need to patch bank'1 of the HEPAX ROM again, at location H´p474 (where p is the page number). Simply replace the current instruction with ¨10B¨ JNC +33d If you´re using YPOKE on the CL you´d of course do: "8xx474-010B" YPOKE where 8xx is the RAM location holding the HEPAX- bank1. Caveat emptor: as always, this is not thoroughly tested yet. Initial checks show it works without a glitch - pls. report if you find any issues. Cheers, 'AM

Re: Getting HEXEDIT to work on the HEPAX itself Message #2 Posted by Ángel Martin on 29 Jan 2012, 6:42 a.m., in response to message #1 by Ángel Martin Just occured to me that I should make a couple of additional remarks: 1. HEXEDIT on the HEPAX will only work while you stay on Bank'1, for obvious reasons 2. DISASM on the hepax will show the second bank code, as this is where the currently excecuting code resides. On the DISASM patch, there is a simpler alternative to Monte´s solution. The FOCAL program below does all three patches for you, assuming the HEPAX ROM is plugged on page A and also using the same CL sRAM addresses as in Monte´s document. 01 LBL "HPXPTCH" 02 "HEPX" 03 PLUG2L 04 "030>83F" 05 AVIEW 06 YMCPY 07 "83F08D-0000" - patches the DISASM glitch 08 YPOKE 09 "8040AC-883F" - maps the patched bank'4 to the MMU 10 YPOKE 11 "02D<83E" 12 AVIEW 13 YMCPY 14 "83E12F-0033" - patches the self-DISASM limitation 15 YPOKE 16 "83E474-010B" - patches the self-HEXEDIT limitation 17 YPOKE 18 "8040A0-883E" - maps the patched bank'1 to the MMU 19 YPOKE 20 "DONE" 21 AVIEW 22 END Enjoy, 'AM Edited: 29 Jan 2012, 6:54 a.m.

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