Some further obscure observations on screen dumps…
Looking over SCDUMP.100 in DL0, I see that a technique similar to the one
you describe is used for a moderately fast screen dump to the EPSON printer:
Each byte of graphics data is broken into two 4-bit nibbles and table of size
16 stored in a data statement is used to store each nibble's upside down image
in a one-byte variable, setting a pair bits for each original bit. No
concatenation is required since the image is printed double size so that the
two nibbles are on different LPRINT'ed lines.
Regards…
<<mike safonov>>
Fascinating, Mike! We have indeed become a nation of BASIC bit-twiddlers! Do
you imagine there's any hope that Microsoft BASIC will be outlawed in our
lifetimes? If the efforts required to EFFICIENTLY solve these trivial problems
weren't so ticklingly absurd, I'd be appalled. Then again, I DO make a good
side income from my radish crop…
winkingly y'rs – tim