Quote:
Originally Posted by Mark1960
Does the video circuit of the pet drive the buffered address bus, or is there a separate interface to video ram?
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On first glance the video RAM address bus (SA....) is separated from the buffered address lines (BA....) by 3 * 74LS157 ICs, circuit sheets 7/8 here. The inputs to the 157s are on the BA... lines (so if your question is can the video circuitry drive the BA... lines - it doesn't seem so). And only BA0 to BA9 are involved, BA10 upwards don't go there.
http://www.zimmers.net/anonftp/pub/c...N/320349-7.gif
http://www.zimmers.net/anonftp/pub/c...N/320349-8.gif