Priviledged - BCL Molecular 18

BCL Molecular 18
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Privileged Instructions
These instructions (NOOP excepted) should be used only by the Operating System. The designation "privileged" is purely symbolic; there is no hardware protection to prevent their use by any application.

000000NOOPNo operation
000001HALT(requires manual resumption from Control Panel)
000002MASKNever used (Hangover from Mk 2?)
000003Acknowledge InterruptLoads B-Register with highest priority interrupting Device Code
000004Interrupt ONEnables interrupts after completion of the immediately following instruction
000005Interrupt OFFDisables interrupts
000006Skip if Interrupt ONTests interrupt state
000007Skip if Interrupt OFFTests interrupt state
000010Skip if MAINS OFFTests and clears Mains Off interrupt
000011Skip if MAINS ONTests and clears Mains On interrupt
000012Skip if PARITYTests and clears Parity interrupt
000013Skip if PROTECTIONNever used
000014Skip if BOUNDARYNever used
000015Skip if MA=SWTests and clears MA=SW interrupt
000016Skip if CONTINUOUS INTERRUPTTests and clear Continuous Interrupt
000017Input/Output RESET(allow 1 second for devices to react)
(C) 2022 Kevin Murrell & The National Museum of Computing
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