You can have the COM port open for both input and output at the same time. I did a TPDD-ish experiment a while ago and wrote some BASIC programs to work with it.
Example: https://github.com/rlauzon54/rdos/blob/master/Clients/RLIST.BA -- Weblog: http://ronsapartment.blogspot.com/ TRS-80 Pocket Computer 2 - TRS-80 Pocket Computer 4 - TRS-80 Model 100/102 - Tandy 1100FD - Tandy 1400LT - Commodore 64 - TRS-80 Model 4P RC2014 (Mini and Pro) - Altair-Duino with TI Silent 700 - VT320 terminal/Raspberry Pi 0 Some people like to work on old cars. But old computers are cheaper and don't require a big garage. Aug 5, 2020, 09:57 by [email protected]: > > Hello Everybody, > > > I have a quick question about serial IO. I have a serial plotter > connected to my 200 and have been sending commands to it, but I haven't > been able to read responses back. I posed it here (only sending > commands): > > https://pay.reddit.com/r/retrobattlestations/comments/i3ol8w/we_dont_get_enough_working_pen_plotters_here_so/> > if you want to see it working. > > > This is the code for sending commands to the plotter: > > > > 5 F$ = "COM:88N1ENN" > 10 OPEN F$ FOR OUTPUT AS 1 > 20 PRINT #1, "IN" > 30 PRINT #1, "SV1" > 40 PRINT #1, "EC" > 50 PRINT #1, "AS4" > 60 PRINT #1, "LB+0000+1050HELLO REDDIT" > 70 PRINT #1, "LB+0000+0900/U/BiggRanger" > 80 PRINT #1, "LB+0000+0750> August4,2020> " > > > > > > > I want to read responses back, I've tried closing the port and then > opening as "FOR INPUT", but that isn't working. I think it may be > clearing the input buffer when opening the port. > > > I want to create a subroutine the sends a command to check the status of > the plotter, receive the string back and parse it to see if the plotter > is busy and keep looping until it's not busy, or there is an error. I > just can't figuer out sending and receiving over serial with the 200. > > > > > > Darren Clark > > > > >
