10 rem Simple QSPI demo using 74HC595 with LED bargraph
  20 dim x as byte, y as byte
  30 dim toggle as pin pm0 for digital output
  40 let y = 100
  50 let toggle = 1
  60 while 1 do
  70   let x = 0x55
  80   qspi x
  90   gosub latch
 100   sleep y ms
 110   let x = 0xaa
 120   qspi x
 130   gosub latch
 140   sleep y ms
 150 endwhile
 160 sub latch
 170   let toggle = 0
 180   let toggle = 1
 190 endsub