Aucbvax.1610
fa.info-cpm
utzoo!duke!mhtsa!eagle!ucbvax!fylstra.tsca@Sri-Unix
Wed Jun 10 19:57:28 1981
suggested enhancement to MODEM206
The following may sound a little over-accomodating, but here goes...

The most recent version of MODEM2 (on [mc]cpm;modem 206asm) assumes
that, in the external coupler case, the transmit and receive data ports
are identical, and that the TBE and RDA status bits occur on the same
port.  I would suggest that the most general case would be

       MODDATR EQU     01H     ;receive data port
       MODDATW EQU     02H     ;transmit data port
       MODCTLR EQU     03H     ;RDA status port
       MODCLTW EQU     04H     ;TBE status port

Then the few occurances of 'OUT MODDATP' would be changed to 'OUT MODDATW'.
While interfacing MODEM206.ASM to a friend's Dynabyte system, I discovered
that the transmit and receive data ports were actually different!  Fortunately
the TBE and RDA bits occur on the same port.  It is unusual, but it does
happen...

Dave Fylstra




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