Date: 2009-01-21 08:18:49
Hallo allemaal, As said I used the extra RAM trick to find out if the BAM sector was loaded. In this case, no. This meant that the original 1541 routines see the external RAM in one or another way. So I started to observe BUFTAB and BUFTAB+1, $99 and $100, very often used to read from/write to buffers in the form of (BUFTAB,X), ($99,X). My expectation was that BUFTAB+1 would point to buffer 8, the external RAM that I use for the BAM. During the copy process buffer 3 was used ($0600) but the very last moment it switched to buffer 1, $0400. Now the weird thing: buffer 1 was filled with the BAM. What routine filled this buffer ??? To manipulate the BAM I needed two zeropage address in able to perform "lda/sta (BamPtr),Y". I took two addresses normally used by the GCR routines, which I don't need anymore. Observing BamPtr+1 I noticed it changed from 11 (= buffer 8) to 0. OK, that is not the 4 I expected but I copy BamPtr+1 to my 7-segments LEDs somewhere in the copy routine. So it is very good possible that BamPtr+1 contained other values in between. What ever changed it, it was not any of my routines because I set it at only one point. I choosed another location for BamPtr and the same happened. Not having that much time anymore, I have a family too, I decided to embed my own routines between SEI and CLI. Bingo, all the copy commands I gave worked perfect and BamPtr didn't change anymore. The big question: what is the interrupt doing to my routines, or vica versa, that causes copy not to work? And why don't I have any problems with normally loading or saving files? Next step is to find out if I can isolate the routine that is the troubleshooter by discarding the inserted SEI/CLI combinations one by one. Until the next update.... -- ___ / __|__ / / |_/ Groetjes, Ruud \ \__|_\ \___| URL: Ruud.C64.org 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. APG Algemene Pensioen Groep NV is gevestigd te Heerlen en is ingeschreven in het handelsregister van de Kamer van Koophandel Limburg onder nummer 14099617 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 it's 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. APG Algemene Pensioen Groep NV is registered in the trade register of the Chamber of Commerce Limburg, The Netherlands, registration number: 14099617 Message was sent through the cbm-hackers mailing list
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