Series II RevD video swap driver

dave
Site Admin
Posts: 560
Joined: Tue Sep 09, 2008 5:24 am

Re: Series II RevD video swap driver

Post by dave » Tue Apr 30, 2019 2:33 am

I picked up a cassette recorder on Ebay, and finally received it today. After twiddling the volume knob a bit, I managed to get get a couple of close reads of the video swap driver, close enough to compare and reconstruct the file to the point where it makes sense. Here it is. I've stripped out all the NULLs and CR (^M) characters, so you may want to add those back in if you're going to try to load this via cassette. The cassette image also included a "RUN" command after the program listing. Let me know if I need to make some corrections.

Code: Select all

 10 FORI=1TO24:PRINT:NEXT:POKE515,0
 100 SI=183:M=PEEK(133)+256*PEEK(134)
 200 M=M-SI:MH=INT(M/256):ML=M-MH*256
 300 POKE133,ML:POKE134,MH
 400 POKE538,ML:POKE539,MH
 500 FORJ=1TOSI:READY
 600 POKEM,Y:M=M+1:NEXT
 700 X=FRE(X):POKE251,0:POKE252,75:POKE255,32
 800 PRINTML+MH*256-772"BYTES FREE.
 900 NEW:END
 1000 DATA133,254,72,165,251,48,11,141,0,216,41,1,133,250,169,255
 1010 DATA133,251,165,250,208,4,104,76,105,255,138,72,152,72,165
 1020 DATA254,164,255,166,253,41,127,201,13,240,90,201,8,240,72
 1030 DATA201,12,240,75,201,10,240,90,201,32,48,26,201,123,16,22
 1040 DATA157,0,211,232,224,123,240,70,208,33,188,0,211,132,255
 1050 DATA169,161,157,0,211,134,253,104,168,104,170,104,76,108,255
 1060 DATA138,41,63,201,10,208,229,138,233,16,170,208,223,138,41
 1070 DATA63,201,59,208,216,138,105,15,170,208,210,152,157,0,211
 1080 DATA202,176,223,152,157,0,211,232,176,229,152,157,0,211,162
 1090 DATA75,208,188,162,75,208,4,152,157,0,211,134,252,169,64,133
 1100 DATA248,160,0,132,246,162,207,232,134,249,134,247,177,248
 1110 DATA145,246,200,240,244,16,247,224,211,208,243,166,252,208
 1120 DATA190,51
Cheers,

Dave

dave
Site Admin
Posts: 560
Joined: Tue Sep 09, 2008 5:24 am

Re: Series II RevD video swap driver

Post by dave » Mon May 20, 2019 12:53 am

Also, see the article in Peek 65 Vol 3 no. 2 (June 1982) on some issues with the driver and how to deal with them.

Post Reply