Hallo Nick, > it definitely involves some mechanical noises. Just before ending the routine it checks if the disk has to be initialised. Could be a try to read the BAM. > Do you know what comes after the check for 1 or 0. It first steps to 2 MHz by setting PA5 and then does some LDA's and STA's on some places for redirecting some IRQ-vectors, changing some flags and chinging the timer in the $1C00-6522. Not those things that could cause the effect you described. > It needs to step-up to > 2MHz, could the circuit associated with this be the cause? No. Check the SCH yourself at FUNET. PA5 just steers a 175 that divides the clock by two or not. Remark: the above is all _AFAIK_. So I could have missed things that could cause the behaviour you observed. ___ / __|__ / / |_/ Groetjes, Ruud \ \__|_\ \___| http://Ruud.C64.org Message was sent through the cbm-hackers mailing list
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