/ ac-mq-blinker.pal - Rapidly modify AC and MQ
/
/ This program twiddles AC and MQ rapidly, with a small amount of delay
/ between each update so the lights aren't just a solid blur.
/
/ While this program runs at full speed, only AC and MQ appear to a
/ human to really change. PC also changes, of course, but since the
/ program spends so much of its time in the delay loop at the top, it
/ appears to be stuck at PC=1.
/
/ It also modifies MB rapidly, but the pattern we use means it looks
/ like the lamps aren't changing, but are all on, dimmed by varying
/ amounts.
/
/ From: http://dustyoldcomputers.com/pdp8/pdp8i/testprogs/acmqblinker.html
/
/ SIMH: SET THROTTLE 333k
PAGE 0
loop, ISZ delay / create a delay
JMP loop
CLA / clear AC so we can load it
TAD value / get value
MQL / stash AC into MQ
TAD value / fetch value again
CMA / complement AC
ISZ value / get to next value
NOP / ignore possible "skip" from ISZ
JMP loop / and do it all again
*20 / skip over the autoincrement registers
delay, 0
value, 0
$