On 5/3/2023 3:43 PM, groepaz_at_gmx.net wrote: > Am Donnerstag, 4. Mai 2023, 00:29:19 CEST schrieb Julian Perry: >> Hello Bo, >> >> Thursday, May 4, 2023, 8:22:31 AM, you wrote: >> >> Please could someone correct me if I'm wrong but I read somewhere that you >> can't use BASIC to do this. BASIC uses indirect indexed mode for peek and >> poke, and that performs a read of the byte after the instruction 1 cycle >> later - immediately unlatching the interrupt. >> >> But it was a long time ago.... > That issue exists indeed - i cant tell if it'd be a problem in this particular > case (i dont know the VIA good enough) - but it'd certainly be worth to try > doing the setup in asm too. > > -- My original program is indeed assembly, but much more complex. I thought a nice short BASIC program might reveal my problem more clearly. Here's the identical program in assembly -- with the exact same results. I have a multimeter sitting on the CA1 line, so I can see it go high->low, and also see the lack of activity. *=$1000lda#<NMIH sta$94lda#>NMIH sta$95lda#0sta$e84dlda#$82sta$ea4eNOSP jsr$ffe1bneNOSP rtsNMIH inc$8000rtiReceived on 2023-05-04 02:00:05
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