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Before this thread wanders COMPLETELY off-topic, I'll throw in my
favorite company name: PMMI.  They made 110 baud modem cards for S-100
computers (the pre-cursor to the PC).  PMMI stood for "Potomac Micro
Magic Incorporated."  And back then, it really was magic... that's how I
hooked up to Ward and Randy's CBBS.

Joe

I did a little digging, and found Ward's original MODEM program.  Here
is the read loop, with the timeout set to 100ms.  Note that 100ms was
just 1250 loops (2500 for a FAST processor).

;THIS SUBROUTINE WILL LOOP UNTIL THE MODEM RECEIVES A CHARACTER
;OR 100 MILLISECONDS. IF A CHARACTER IS RECEIVED, A FLAG IS SET
;TO STORE THE CHARACTER. A MAXIMUM OF TWO CHARACTERS ARE STORED,
;BUT MORE MAY BE STORED IF DESIRED (SEE COMMENT IN "INTDSKSV"
;ABOVE).

INMODEM: LDA    FASTCLK
        ORA     A
        JZ      SLOW
        LXI     B,2500
        JMP     TIMERL

SLOW:   LXI     B,1250
TIMERL: CALL    IN$MODlsr
        CALL    ANI$MODRCVB
        CALL    CPI$MODRCVR
        JZ      GETBYTE
        DCX     B
        MOV     A,B
        ORA     C
        JNZ     TIMERL
        RET


> From: James H H Lampert
> 
> Incidentally, my old Tandy 1000SL had an EMS card made by a company
called
> "Micro-Mainframe."


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