Maybe the research and wiki articles I did for HTERM. http://bitchin100.com/wiki/index.php?title=Special%3ASearch&search=Serial+port&fulltext=Search
Scroll down the page there are articles on the model 100 and 200 serial port programming. -- John. On Sun, Oct 6, 2019, 9:41 AM Russell Davis <[email protected]> wrote: > I recall seeing recently an asm listing on how to twiddle with the rs232 > on the m100/102/200 but I can't recall where I saw it or find it in my > browser history. Does anyone know what i'm talking about and know where to > find it? > > -Russell > On 10/6/2019 11:40 AM, Russell Davis wrote: > > Thanks for doing that. > > while trying to workout what was going on I stumbled across > https://www.web8201.net/files/LIBRARY_web8201/M100SIG/Lib-10-Tandy200/NULMDM.200 > which said tie the RTS/CTS together for the T200 which seems to be what you > worked out. > > -Russell > > > On 10/6/2019 10:47 AM, Kurt McCullum wrote: > > Guys, I did some testing on my T200 to figure out the whole serial port > wiring issue. > > Test 1: > 1. Write a test application to open the serial port on the PC with > DTR/DSR and CTS/RTS disabled > 2. Go to TELCOM on the T200 > 3. STAT 98N1ENN > 4. TERM > 5. Press any key on the T200 and it freezes. > > Test 1: > 1. Write a test application to open the serial port on the PC with > CTS/RTS disabled but DTR/DSR enabled > 2. Go to TELCOM on the T200 > 3. STAT 98N1ENN > 4. TERM > 5. Press any key on the T200 and it freezes. > > Test 3: > 1. Write a test application to open the serial port on the PC with > CTS/RTS enabled but DTR/DSR disabled > 2. Go to TELCOM on the T200 > 3. STAT 98N1ENN > 4. TERM > 5. Press any key on the T200 and all data is sent to the PC and sent > back to the T200. Works perfectly. > > I Then tested to see if TELCOM is actually using RST/CTS. For this I wrote > a small application to send a large file to the T200 with Xon/Xoff turned > off. I then put a bit of code in place to see if the RTS/CTS flags were > ever changed by the T200 to tell the PC to stop sending. What I found was > that the T200 never sent a flag to the PC signaling to pause sending data > due to the buffer being full. This caused garbage on the screen. > > So, what I can conclude from all of this is that the T200 serial port > hardware MUST have the RTS/CTS active or it will freeze the hardware. But > the TELCOM application does not use those signals to halt data transfer > when the buffer is full. Instead it relies on Xon/Xoff. Hope that clears > things up a bit on the mystery of the T200 serial port. > > Kurt > >
