Date: 2006-08-01 12:36:11
Hallo Anders, > The first few bytes are vectors to $B009 (start) and $B076 Ah, thanks! Hadn't seen that yet. > Maybe someone finds it interesting to compare the VIC-1112 > ROM dump.... In fact I started disassemble it to find out how it works, this because of the weird behavior of the C64 IEEE interfaces. (This evening I want to test the VIC-1112's with CBM-HD as well.) But I already found out (but not for 100% sure yet) that the used protocol doesn't look exactly what I expected: it doesn't handle both NRFD and NDAC as it should according the official IEEE timing diagrams. If this indeed is the case, then it seems that CBM-HD indeed is to blame because it is not flexible enough. Regarding the C64 IEEE intefaces: as engineer I would rather use the VIC-1112 as base then one of the original IEEE drives. A simplified protocol would explain my troubles. Only funny that the drives themself except it as well. > ... and see if they have anything in common. I found pieces of code with no reference at all. Not one or two, but about twenty! I first ruled out the obvious things like JMP and JSR. Next I checked the JMP (xxxx) construction: lda #$xy sta RAM lda #$Bz sta RAM+1 JMP (RAM) In this case I looked for #$B in my sources and of course I found one or two but not enough to cover the twenty I'm talking about. Another weird thing: the piece starting at $B273 is also interesting: it stores data at $9C01, the IO3 area. Another piece can be found at $B0DD. This piece calls a routine at $B59D which stores into and reads data from $9C01. $9C00 is used as well. My impression is that someone used an already existing cartridge as base to create this one. A very sloppy job IMHO. OK, but as already said, I haven't finished the disassembling yet so we stil can run into some suprises. -- ___ / __|__ / / |_/ Groetjes, Ruud \ \__|_\ \___| URL: Ruud.C64.org =====DISCLAIMER================================================================= De informatie in dit e-mailbericht is vertrouwelijk en uitsluitend bestemd voor de geadresseerde. Wanneer u dit bericht per abuis ontvangt, verzoeken wij u contact op te nemen met de afzender per kerende e-mail. Verder verzoeken wij u in dat geval dit e-mailbericht te vernietigen en de inhoud ervan aan niemand openbaar te maken. Wij aanvaarden geen aansprakelijkheid voor onjuiste, onvolledige dan wel ontijdige overbrenging van de inhoud van een verzonden e-mailbericht, noch voor daarbij overgebrachte virussen. The information contained in this e-mail is confidential and may be privileged. It may be read, copied and used only by the intended recipient. If you have received it in error, please contact the sender immediately by return e-mail; please delete in this case the e-mail and do not disclose its contents to any person. We don't accept liability for any errors, omissions, delays of receipt or viruses in the contents of this message which arise as a result of e-mail transmission. De Stichting Pensioenfonds ABP is gevestigd te Heerlen en ingeschreven bij de Kamer van Koophandel Zuid Limburg onder nummer 41074000 Message was sent through the cbm-hackers mailing list
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