On Thu, Sep 24, 2015 at 05:34:53PM -0700, Terry Raymond wrote: >but one keyboard the restore key barely responds This is normal, I think. On the C64 there is a heavy debouncing circuit on the RESTORE key, which has a dedicated line, not part of the keyboard matrix. >This NTSC Vic when powered up takes a little longer to display the Rom >greeting This is also normal. I suspect that it is holding the RESET line low longer than the C64 does. Because of this super-long delay, my Vic Flash Plugin firmware skips the RAM check, to get the start-up time somewhat at par with the C64. >I will see how the Vic-20 acts this time so will mention the results. On the Vic-20, the RESTORE key is not debounced at all. If you carefully half-press or shake it, it can generate enough NMIs so that the computer will hang or crash due to stack overflow. (Pressing RESTORE alone should have no visible effect; the NMI handler will check if STOP was pressed as well. But when you half-press, you can get the stack overflow.) Marko Message was sent through the cbm-hackers mailing listReceived on 2015-09-25 11:00:08
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