Also, if you want to prevent the lockups, you could loop back DTR to DSR as described earlier in this thread.
—b9 On Thu, Dec 22, 2022 at 10:10 AM B 9 <[email protected]> wrote: > Thanks for doing that direct test from your Tandy 200 to 102. That > confirms that the Tandy 200's TELCOM program (and possibly anything that > calls the ROM to read the serial port) is different. I hadn't known that > before. I think it must be a bug because even a program that uses DSR to > find out whether another device is connected shouldn't hang and require > Shift-Break. > > Are there any ROM experts here who know what the difference is? Maybe > it'll be possible to patch the Tandy 200's ROM. > > By the way, XON/XOFF is pretty much required. As Jim said, TELCOM does not > support hardware handshaking. > > —b9 > > > > On Thu, Dec 22, 2022 at 1:14 AM Cedric Amand <[email protected]> wrote: > >> I'm super interested in those serial problems, but I can't fully grasp >> John's phrase below, would you please clarify and elaborate a bit ? >> >> > 3 wire is all the model 100 / 200 actually uses unless you're using >> HTERM >> > or you like the godlike simplicity of the cable check lockup, or you >> cannot disable the cable check in software. >> >> I often have lockups on my M200, I'm also under the impression (but I'm >> no expert yet) that in some way it's serial (in this case null modem) >> implementation niside TERM differs from the one of the M102. If I do a >> direct null modem (full cable) between a M102 and a M200, with TERM, the >> M200 will systematically lockup when the M102 hangs up ( EXIT/F8 ) whereas >> the reverse is not true. >> This with both ends using (or supposed to use) hardware handshake (and >> xon/xoff disabled) >> This is pure observation and might be specific to my setup, of course. >> >> However if you could please elaborate a bit about how the M10x/M200 uses >> the serial lines, that would be much appreciated >> >> I "think" from my hours of fiddling that null modem serial on the >> M10x/M200 only works reliably with xon/xoff and the hardware only handshake >> (at least in TERM) is flaky on the receiving end. I have yet to try HTERM. >> (It's for sure on my todo) >> >> >
