M9301

Switch bank: S1-1 low ROM enable, OFF = disable lower 256 word 765000-765777 In my YD version that is some of the boot devices, some tests S1-2 ON=POWER UP REBOOT ENABLE, OFF=no boot on power up parallel to TP1; if OFF, only TP2 low (TP3=GND) will boot S1-3 to S1-10 word address offset, boot address = 173000 + (S)<<1 normally OFF Boot process: perform some tests, infinite loop when fail print some register contents (console) prompt for command (console) enter console emulator command (L adr, D data, E[xamine], S[tart]) or boot device code (PR paper tape, DK RK05, ... ) if boot device: further tests, then boot from device My doc is up to YD version only; the difference is different supported devices, I believe. John G. Zabolitzky