>> Can you explain why I need the synchronisation? I'm interested in >> understanding if I've missed something here. Do you mean things like raster >> coding, etc? >Raster effects are one aspect. But more importantly, the serial IEC >bus requires very strict timing, which I doubt is possible with the >approach described. Indeed, and JiffyDOS is even more strict tolerating an error of about 3-4us. That is why it is proposed these routines are run 100% on the real 6510. When a kernal call is made to an IEC routine on the virtual engine, it is trapped and control handed over to the 6510 as a JSR xxxx. Timing done at 1MHz and then RTS brings the virtual engine back into control. That protects for behaved programs which use the kernal ROM, but not for those that code their own routines. The SuperCPU as I understand it has the same problem and you have to flick the 1/20 switch before loads/saves if the program by-pass the Kernal. Through *training* non-kernal calls can also be added to the "1MHz exemption table". That way a database can be built up from user experiences. Any other situations? - Nick 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) 2000: Orbital Engine Company (Australia) PTY LTD and its affiliates Message was sent through the cbm-hackers mailing list
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