Tom, Looks like you will need to either build or buy a cable. My two cents is below but I'm sure others will chime in. There are several options out there.
Here is a description of what I do with all my Model-T units. I start with this DB25 to DB9 adapter which is just a regular DB9 to DB25 converter. I attach these with some 2.5mm (should be 2.6mm) screws to the Model-T so its always attached. https://www.sfcable.com/db9-female-to-db25-male-serial-mini-adapter.html Then I put one of these adapters in between the DB9 serial port and the 9-25 adapter which creates a null modem cable. https://www.sfcable.com/null-modem-adapter-db9-db25/db9-male-to-female-null-modem-mini-adapter.html For my T200 I have remove pin 1 from the null modem adapter to make it happy but that's a quick fix with needle nose pliers. Everybody has there preference on cable setup so eventually you will come up with a solution that works for you. Sounds like what you have is working for text transfers so that's a start. Kurt On Tue, Apr 9, 2019, at 5:59 PM, Thomas Morehouse wrote: > Thanks Kurt. > > Testing the DB9-DB25 adapter only - not the usb/serial cable - I have > continuity NOT from pin 4 of the DB9 to pin 6 of the DB25. I have continuity > from pin 4 of the DB9 to pin 20 of the DB25. That's using the numbers printed > at the pins themselves. > > Should I even bother testing the others you suggest? Sounds like the adapter > already fails the test. > > Tom M. > > > On Tue, Apr 9, 2019 at 8:48 PM Kurt McCullum <[email protected]> wrote: >> __ >> Ignore the USB to serial piece of the puzzle. As Brian said, it's just a >> serial port. Test the 9 to 25 adapter. One end will be female so it's easier >> to put something like the end of a paper clip into one hole at a time then >> put the probe on that. >> >> Kurt >> >> On Tue, Apr 9, 2019, at 5:22 PM, Thomas Morehouse wrote: >>> OK - looks like I wasn't clear. In Kurt's post, he writes: >>> >>> "Take one probe of the meter and put it on pin 4 of the DB9 and the other >>> on pin 6 of the DB25. It should beep or light up (however you meter >>> functions to indicate a connection). Then do the same for the DSR line on >>> pin 6 to pin 20. And finally the RTS and CTS pins 7->5 and 8-> 4. If they >>> are crossed in some manner, then you will not get a beep or a light." >>> >>> If the usb/serial cable is a single unit (usb at one end, DB9 at the >>> other), how do I put one probe of the meter on the DB9 and the other probe >>> of the meter on the DB25? There's no DB25 on the cable, unless I plug the >>> 9-25 adapter into the DB9 - but then I can't put a probe on the DB9. Jeez I >>> feel dense. >>> >>> I'm really sorry I can't follow this, but maybe I'm just overlooking >>> something really simple? >>> >>> Thanks. >>> Tom M. >>> >>> >>> On Tue, Apr 9, 2019 at 7:56 PM Brian K. White <[email protected]> wrote: >>>> You don't check continuity on the usb-serial adapter. That isn't just a >>>> cable, it's really a peripheral like a disk drive or a printer, it just >>>> happens to be a peripheral that all fits entirely inside the plug >>>> housing on one end of it. There is no simple direct wire mapping between >>>> the usb pins and the serial pins. Between the usb pins and the serial >>>> pins, there is circuit board with a chip and a few other components >>>> which is converting and translatine between two entirely different kinds >>>> of signals and protocols. >>>> >>>> You treat the usb-serial adapter as just a serial *port*, and ignore >>>> that it looks like a wire. Just pretend it's like a serial port built in >>>> to the back of an old desktop. >>>> >>>> You check the continuity of the serial cable, which IS "just a cable". >>>> Or, really, you check the continuity of the combined serial cable with >>>> any null-modem and gender-changer adapters, and treat that all together >>>> as one "cable". >>>> >>>> -- >>>> bkw >>>> >>>> On 4/9/19 6:56 PM, Thomas Morehouse wrote: >>>> > Thanks Kurt. I'm even denser than usual tonight I guess. >>>> > >>>> > From earlier posts, seems the problem (102 screen dimming) is likely >>>> > caused by the usb/serial cable. One end of the cable is a usb plug; >>>> > other end is the DB9. >>>> > >>>> > So I'm afraid I don't know how to test continuity on the cable. I can >>>> > find pin 4 of the DB9 - but where does the DB25 fit in the picture? >>>> > >>>> > Or, are you saying to test the cable with the DB9/DB25 adapter plugged >>>> > into the cable? >>>> > >>>> > Sorry to be the dolt again. >>>> > Tom M. >>>> > >>>> > >>>> > On Tue, Apr 9, 2019 at 10:57 AM Kurt McCullum <[email protected] >>>> > <mailto:[email protected]>> wrote: >>>> > >>>> > There are store bought cables that work well. Brian has done a >>>> > great job putting together a list of those cables. For my machines >>>> > I have a mixture of custom made cables or slim adapters. Both >>>> > methods work and give me the pinout below. When you get the cable >>>> > right, your M102 will be happy. >>>> > >>>> > But to the question at hand, don't tear apart your cable. Check >>>> > it. Right now you know that pins 2,3 and 5 are all going to the >>>> > right locations. You will need to check pins 4,6,7 and 8. Since >>>> > those are paired lines (4/6, 7/8) one or both pairs will be flipped. >>>> > >>>> > If you have a multi-meter which has a continuity check on it then >>>> > you test both ends of the wire. >>>> > >>>> > Here is what I have found to work on all my machines and I include >>>> > this in the mComm manual. >>>> > >>>> > 7 Wire Cable >>>> > PC >>>> > >>>> > Model-T >>>> > DCD >>>> > 1 >>>> > NC >>>> > >>>> > >>>> > RX >>>> > 2 >>>> > → >>>> > 2 >>>> > TX >>>> > TX >>>> > 3 >>>> > ← >>>> > 3 >>>> > RX >>>> > DTR >>>> > 4 >>>> > ← >>>> > 6 >>>> > DSR >>>> > GND >>>> > 5 >>>> > ↔ >>>> > 7 >>>> > GND >>>> > DSR >>>> > 6 >>>> > ← >>>> > 20 >>>> > DTR >>>> > RTS >>>> > 7 >>>> > → >>>> > 5 >>>> > CTS >>>> > CTS >>>> > 8 >>>> > ← >>>> > 4 >>>> > RTS >>>> > RI >>>> > 9 >>>> > NC >>>> > >>>> > >>>> > >>>> > >>>> > Take one probe of the meter and put it on pin 4 of the DB9 and the >>>> > other on pin 6 of the DB25. It should beep or light up (however >>>> > you meter functions to indicate a connection). Then do the same >>>> > for the DSR line on pin 6 to pin 20. And finally the RTS and CTS >>>> > pins 7->5 and 8-> 4. If they are crossed in some manner, then you >>>> > will not get a beep or a light. >>>> > >>>> > Hope that makes sense. >>>> > >>>> > Kurt >>>> > >>>> > >>>> > On Tue, Apr 9, 2019, at 7:38 AM, Thomas Morehouse wrote: >>>> >> Thanks for the comments gents. Learn something every day. >>>> >> >>>> >> Kurt, on the "crossed wires" issue, what is the procedure for >>>> >> fixing the problem? I sure don't want to pull something apart, >>>> >> or buy even *more* adapters! >>>> >> >>>> >> Thanks. >>>> >> Tom M. >>>> >> >>>> >> >>>> >> On Tue, Apr 9, 2019 at 10:03 AM Kurt McCullum <[email protected] >>>> >> <mailto:[email protected]>> wrote: >>>> >> >>>> >> >>>> >> What you are describing happens to me when the either the >>>> >> CTS/RTS or DTR/DSR wires in your cable are crossed. >>>> >> >>>> >> Example. The CTS pin listens (checks for voltage) to the RTS >>>> >> pin on the other end. If you have a cable where RTS goes >>>> >> straight to RTS and CTS going straight to CTS, then you have >>>> >> two ends of the cable both feeding voltage to the same wire. >>>> >> This causes the screen to go dim. the DTR/DSR pins can >>>> >> produce the same issue. >>>> >> >>>> >> Kurt >>>> >> >>>> >> On Tue, Apr 9, 2019, at 5:33 AM, Thomas Morehouse wrote: >>>> >>> Now that I've got my usb/serial link working (M102 to Dell >>>> >>> laptop), I notice the 102's screen get quite dim when the >>>> >>> cable is in the 102's 25 pin serial port. >>>> >>> >>>> >>> Doesn't need to be connected to the Dell. Just when you plug >>>> >>> the usb/serial cable into the 102. Unplug the cable, 102 >>>> >>> screen returns to normal visibility. >>>> >>> >>>> >>> Something to worry about? or just live with it? I wouldn't >>>> >>> have thought the usb/serial cable chip would put such a >>>> >>> drain on the system. Happens with battery power, or even >>>> >>> with external 6 volt poweer. >>>> >>> >>>> >>> Thanks. >>>> >>> Tom M. >>>> >>> >>>> >> >>>> > >>>> >>
