On 09/03/2018 10:14 AM, André Fachat wrote: > Hi Bo, > > Am 3. September 2018 09:52:20 schrieb Bo Zimmerman <bo@zimmers.net>: > >> Hello all, >> >> After check both(!) books on Plus/4 programming, and the 6551 schematic, >> and doing experimenting... I have a question. Does anyone know the >> kosher way to change the user port RTS signal so that the modem knows to >> stop transmitting data while a program catches up? I'm initializing the >> Command Register to 5 (RTS low/enabled, DTR enabled, IRQ, no party, no >> echo). But bad things seem to happen when I attempt to touch it again >> to change RTS to high/disabled. Does anyone have any knowledge or >> experience with this? > > In my experience the rts/cts/dtr lines are completely broken in the ACIA. > > They switch off rx and/or tx at inconvenient times and in the middle of > transactions. > > So no, I don't know a good wayof using them, sorry I only know about CTS being broken, it will turn off the transmitter in the middle of a byte and that's why the CTS line of the 6551 in the Plus/4 is connected to GND. RTS is an output and tells the other side that you are ready to receive data. GerritReceived on 2018-09-03 17:00:05
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