$F04D/61517:   Input From RS232

Jump from $F227:

F04D: 85 99     STA $99       ; Default Input Device (0)
F04F: AD 94 02  LDA $0294     ; RS232 Pseudo 6551 command Register Image
F052: 4A        LSR
F053: 90 28     BCC $F07D
F055: 29 08     AND #$08
F057: F0 24     BEQ $F07D
F059: A9 02     LDA #$02
F05B: 2C 01 DD  BIT $DD01     ; CIA2: Data Port B (User Port, RS232)
F05E: 10 AD     BPL $F00D     ; No DSR (Data Set Ready) Error
F060: F0 22     BEQ $F084

Jump from $F066:

F062: AD A1 02  LDA $02A1     ; RS232 Enables
F065: 4A        LSR
F066: B0 FA     BCS $F062
F068: AD 01 DD  LDA $DD01     ; CIA2: Data Port B (User Port, RS232)
F06B: 29 FD     AND #$FD
F06D: 8D 01 DD  STA $DD01     ; CIA2: Data Port B (User Port, RS232)

Jump from $F075:

F070: AD 01 DD  LDA $DD01     ; CIA2: Data Port B (User Port, RS232)
F073: 29 04     AND #$04
F075: F0 F9     BEQ $F070

Jump from $F082:

F077: A9 90     LDA #$90
F079: 18        CLC
F07A: 4C 3B EF  JMP $EF3B     ; Disable Timer

Jump from $F053, $F057:

F07D: AD A1 02  LDA $02A1     ; RS232 Enables
F080: 29 12     AND #$12
F082: F0 F3     BEQ $F077

Jump from $F060:

F084: 18        CLC
F085: 60        RTS

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