On 2/8/20 12:25 PM, silverdr_at_wfmh.org.pl wrote: > Under the lower (and upper) border, the VICs data sequencer is stuck at the last byte of the selected video ram bank ($3fff for default bank 0). That's where the bitmap data comes from. Does anyone know/remember where its colour information comes from? Or is it always $x0 as "unconnected"? > The color of a pixel is determined by either the value of some color register (any of $d020-$d02e) or some selection from the 40x12bit cache. There are 40 word lines connected to the cache that get activated in sequence during normal display (see my previous ramblings about this in the archive). Outside of the display (in normal operation, between lines 251 and 51) the word lines are not activated, so the bit in the chip that reads the color bits from the cache reads all zeroes, i.e. black color. This is also the reason that the display becomes entirely black outside of the border if you turn on bit map mode (since then both foreground and background color are determined by the 40x12 cache.) Cheers MichielReceived on 2020-05-30 00:54:13
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