Date: 2003-12-05 08:26:20
Hello Ruud, With 64HDD I have found you need to have support for 16channels (secondary addresses) for each device number, and keep track of all. You can handle the situation you mention by "holding-off" the C64 until you complete any internal operations. On the serial bus this is done by holding the DATA line active (low) and the C64 won't be able to send any new instructions until the internal operation is done, and the line freed (at least that's how I remember doing it...). The parallel IEC bus would have a similar "hold-off" method, just not sure which signal line is used.... - Nick -----Original Message----- From: Baltissen, GJPAA (Ruud) [mailto:firstname.lastname@example.org] Sent: Friday, 5 December 2003 2:52 PM To: 'email@example.com' Subject: Multi disk emulator Hallo allemaal, I want to expand my 4040-emulator so one PC can emulate more then one drive. So I need an unique thing to handle requests coming from the CBM. My question: is device and channel unique enough? When giving the command OPEN 1,8,15,"V" you cannot use file 1 again because the C= will reject it with FILE IS OPEN error. (or something like it. I'm not at home, so I cannot check it) So I thought "Eureka!" but then I wondered what would happen if you gave the command OPEN 3,8,15,"I" while the floppy still was validating the disk. Last evening I tried the above in al little BASIC program on my C64: 10 open 1,8,15,"v0" 20 print "aaaaa" 30 open 3,8,15,"i0" 40 print "bbbbb" 50 close 1 : close 3 This worked so far that the "aaaaa" was displayed and the C64 had to wait until the validate was finished. In other words, the drive refused to accept any other command until its present task is finished. Hmmm, just popped in my mind: I could also have said '30 print#1,"i0"' which IMHO would have ended in the same behaviour. The consequence of running more then one device/drive on a PC is that as long as the PC is busy with something, it is blocked for further commands. There is only one thing I worry about. I'm reasonably sure there a way to make two drives exchange data with each other directly. Thus no 'load"xxxx",8' and 'save"xxxx",9' where the CBM serves as a buffer but a direct data exchange. I'm afraid that that is out of the question for the moment. Thanks for any info/comment. -- ___ / __|__ / / |_/ Groetjes, Ruud \ \__|_\ \___| http://Ruud.C64.org <http://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. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Your Engineering Solutions Provider http://www.orbeng.com.au/orbital/engineeringServices/engServices.htm - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - PLEASE TAKE NOTE: The contents of this email (including any attachments) may be privileged and confidential. Any unauthorised use of the contents is expressly prohibited. If you have received this email in error, please advise us immediately (you can contact us by telephone on +61 8 9441 2311 by reverse charge) and then permanently delete this email together with any attachments. We appreciate your co-operation. Whilst Orbital endeavours to take reasonable care to ensure that this email and any attachments are free from viruses or other defects, Orbital does not represent or warrant that such is explicitly the case (C) 2003: Orbital Engine Company (Australia) PTY LTD and its affiliates Message was sent through the cbm-hackers mailing list
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