0572   72C6             ;
0573   72C6             ;  WRITE SERIAL OUTPUT
0574   72C6             ;  A = CHAR TO BE OUTPUT
0575   72C6             ;
0576   72C6 20 1D 73    WRT    JSR DLY2
0577   72C9 A2 09              LDX #9
0578   72CB             WROC   =WRT
0579   72CB 49 FF              EOR #$FF          ; COMPLEMENT A
0580   72CD 38                 SEC
0581   72CE             ;
0582   72CE 20 DA 72    WRT1   JSR OUT
0583   72D1 20 1D 73           JSR DLY2
0584   72D4 4A                 LSR A
0585   72D5 CA                 DEX
0586   72D6 D0 F6              BNE WRT1
0587   72D8 F0 3F              BEQ RDT5
0588   72DA                                      ; *USE BNE?
0589   72DA             ;
0590   72DA 48          OUT    PHA               ; SAVE A
0591   72DB AD 02 6E           LDA MPB           ; OUTPUT BIT FROM CY
0592   72DE 29 FD              AND #%11111101
0593   72E0 90 02              BCC OUT1
0594   72E2 09 02              ORA #%00000010
0595   72E4 8D 02 6E    OUT1   STA MPB
0596   72E7 68                 PLA               ; RESTORE A
0597   72E8 60                 RTS
0598   72E9             ;
0599   72E9             ;  OUTPUT  RETURNS CHAR IN A
0600   72E9             ;
0601   72E9 A5 E7       RDT    LDA HSPTR         ; TEST HS PTR OPTION
0602   72EB 4A                 LSR A
0603   72EC B0 4F              BCS RDHSR
0604   72EE             RDOC   =RDT
0605   72EE A2 08              LDX #8
0606   72F0             ;
0607   72F0 AD 02 6E    RDT1   LDA MPB
0608   72F3 4A                 LSR A             ; WAIT FOR START BIT
0609   72F4 90 FA              BCC RDT1
0610   72F6             ;
0611   72F6 20 20 73           JSR DLY1
0612   72F9 20 DA 72           JSR OUT           ; ECHO START BIT
0613   72FC             ;
0614   72FC 20 1D 73    RDT2   JSR DLY2
0615   72FF AD 02 6E           LDA MPB           ; CY = NEXT BIT
0616   7302 4A                 LSR A
0617   7303 20 DA 72           JSR OUT           ; ECHO
0618   7306             ;
0619   7306 08                 PHP               ; SAVE BIT
0620   7307 98                 TYA               ; Y CONTAINS CHAR BEING FORMED
0621   7308 4A                 LSR A
0622   7309 28                 PLP               ; RECALL BIT
0623   730A 90 02              BCC RDT4
0624   730C 09 80              ORA #$80          ; ADD IN NEXT BIT
0625   730E A8          RDT4   TAY
0626   730F CA                 DEX
0627   7310 D0 EA              BNE RDT2          ; LOOP FOR 8 BITS
0628   7312 49 FF              EOR #$FF          ; COMPLEMENT DATA
0629   7314 29 7F              AND #$7F          ; CLEAR PARITY
0630   7316             ;
0631   7316 20 1D 73           JSR DLY2
0632   7319 18          RDT5   CLC
0633   731A 20 DA 72           JSR OUT           ;AND DELAY 2 HALF-BIT-TIMES
0634   731D             ;
0635   731D 20 20 73    DLY2   JSR DLY1
0636   7320 48          DLY1   PHA               ; SAVE FLAGS AND A
0637   7321 08                 PHP
0638   7322 8A                 TXA               ; SAVE X
0639   7323 48                 PHA
0640   7324 A6 EA              LDX MAJORT
0641   7326 A5 EB              LDA MINORT
0642   7328             ;
0643   7328 8D 04 6E    DL2    STA MCLKIT
0644   732B             ;
0645   732B AD 05 6E    DL3    LDA MCLKIF
0646   732E 10 FB              BPL DL3
0647   7330 CA                 DEX
0648   7331 08                 PHP
0649   7332 AD 04 6E           LDA MCLKRD        ; RESET TIMER INT FLAG
0650   7335 28                 PLP
0651   7336 10 F3              BPL DL3
0652   7338             ;
0653   7338 68                 PLA               ; RESTORE REGS
0654   7339 AA                 TAX
0655   733A 28                 PLP
0656   733B 68                 PLA
0657   733C 60          DLX    RTS