So far I have found these hardcoded jumps to the edit rom that do not go through the jump table: Pasting from my disassembly... ;-------------- Output to Screen (Called from CHROUT in KERNAL) ; ***** THIS ENTRY POINT MUST NOT MOVE!!! ***** *=$E202 ;-------------- Main IRQ Entry Point (Called from KERNAL vector at $FFFE !!!!) ; ***** THIS ENTRY POINT MUST NOT MOVE!!! ***** *=$E442 Steve >________________________________ > From: Rhialto <firstname.lastname@example.org> >To: email@example.com >Sent: Monday, April 15, 2013 7:20:12 PM >Subject: Re: My ColourPET Project > > >On Mon 15 Apr 2013 at 11:25:35 -0700, Steve Gray wrote: >> I am currently disassembling and commenting both 40 and 80 column >> roms, but I don't have a lot of experience with the DIN roms. I think >> there is extra code in there. >> Which ROM did you try to modify? >> >> It seems the following are issues to watch out for: >> >> - CRTC vs NON-CRTC (not much of an issue now) >> - 9" vs 12" Monitor Size- Screen standard (NTSC / PAL / Custom) > >9" would all be without CRTC, I think. Unless somebody swapped a new >board into an old case. > >> > First PET had NTSC, rest seem to have custom (ie: 20kHz) >> - 40 / 80 column: >> > screen line linking >> > screen line address table >> > default character set (text / graphics) >> - Keyboard Tables (N / B / DIN / Custom) > >Somebody already mentioned that there are different rules about which >keys may be shifted with the Business keyboard (in general, the Normal >keyboard allows shifting on all keys and adds 128). > >Some versions of the Editor ROM don't have the jump table at the start. >IIRC these would be the pre-basic-4 ones, and the basic 4 upgrade for >non-CRTC machines. My notes say (I happened across them recently) that >despite the lack of a jump table, many routines actually start in the >same location (as what? that it didn't say) so that *not* using the jump >table would actually be more compatible across versions. > >-Olaf. >-- >___ Olaf 'Rhialto' Seibert -- The Doctor: No, 'eureka' is Greek for >\X/ rhialto/at/xs4all.nl -- 'this bath is too hot.' > > > Message was sent through the cbm-hackers mailing list > > > Message was sent through the cbm-hackers mailing listReceived on 2013-04-16 01:00:27
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