How fast can a 6502 transfer memory?
This also misses loop unrolling, combined with an assembly language version of &quot;Duff&#x27;s device&quot; to be able to do an arbitrary number of transfers even if your loop is unrolled to, say, 8 transfers.<p>This stuff used to matter!  I had an NCR5380 chip on an Amiga, simple, memory mapped I&#x2F;O, no DMA or interrupts.  To get a tape drive to stream (remember that?) the byte transfer loop really had to be tweaked.  But once fully tweaked, &quot;whoooooooosh&quot; instead of &quot;chugga chugga chugga&quot;.<p>And truly heroic programming techniques had to be employed on the C64 to do X&#x2F;Y smooth scrolling games.  Often a static part of the screen, conveniently displaying scores etc, existed to make it work - there was just enough bandwidth to do 80% of the screen, say, so you find an excuse to keep the rest of it static.<p>I kinda miss those days, and I kinda don&#x27;t.  I guess it was good to have experienced them.