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Elite on the BBC Micro

Tube: PUTBACK [6502SP version, I/O processor]

Name: PUTBACK [Show more] Type: Subroutine Category: Tube Summary: Reset the OSWRCH vector in WRCHV to point to USOSWRCH Deep dive: 6502 Second Processor Tube communication
Context: See this subroutine in context in the source code References: This subroutine is called as follows: * ADDBYT calls PUTBACK * ADPARAMS calls PUTBACK * CLYNS calls PUTBACK * DOBULB calls PUTBACK * DOCATF calls PUTBACK * DOCOL calls PUTBACK * DODIALS calls PUTBACK * DOFE21 calls PUTBACK * DOHFX calls PUTBACK * DOSVN calls PUTBACK * DOVIAE calls PUTBACK * ECBLB calls PUTBACK * SETVDU19 calls PUTBACK * SETXC calls PUTBACK * SETYC calls PUTBACK * STARTUP calls PUTBACK * prilf calls PUTBACK * printer calls PUTBACK
.PUTBACK LDA #128 \ Set A = 128 to denote the first entry in JMPTAB, i.e. \ USOSWRCH \ Fall through into USOSWRCH to set WRCHV to the first \ entry in JMPTAB - in other words, put WRCHV back to \ its original value of USOSWRCH