Hi Jonathan, My whole setup is a total kludge / hack that I never expected to use long term. I was just doing a POC and built the whole thing in about 10 minutes with stuff I had laying around but here we are almost five years later... One day I'll get off my butt and make a proper 3d printed case etc.
I'll provide some amazon links to similar stuff I used but shop around I'm sure you'll find better prices. I was building contact tracing devices during Covid so had a surplus of Pi Zero's and these cases: https://www.amazon.com/Vilros-Raspberry-Zero-Compatible-Transparent/dp/B08ZDPNM4H I cut a hole in it with a file, drilled two holes for the screw mounts. I used a standard bulk-head mount DB-25 Pin male connector, cut all the pins off the backside so they were flush, used some small gage wire to connect to a Mini RS232 to TTL MAX232 Convert board like these: https://www.amazon.com/KOOBOOK-MAX3232-Converter-Adaptor-Transfer/dp/B07VNLVJ57 Wired up TX/RX to the RIN1 and ROUT1 of the converter board, then wired the DIN1 / DOUT1 to the proper GPIO ports on the PI soldering directly to the pads. Grabbed 3V off the Rpi to power the converter. (3V ran cooler than trying to run off 5V. 5V got super hot.) Here are some photos of the unit including a bonus photo of me on the bus being all cyber-punk with my M102 and my heads up display. It was pandemic times so forgive the mask. https://niedobry.com/mod100/tanpi/ On Wed, Dec 13, 2023 at 7:06 AM [email protected] < [email protected]> wrote: > Hello, > > I know it is starting to be off-topic, but some details about how you did > the pi (I assume a zero-w) and the case with the level-shifter would be > nice. I've done this with other components, but I've never gotten anything > nearly so small. I have a pi-hat with a level shifter, and it basically > doubled the size of pi zero. Something this small and that would plug > right into the serial port of the m100 would be great. > > Jonathan > > >----Original Message---- > >From : [email protected] > >Date : 2023-12-13 - 02:11 (CEST) > >To : [email protected] > >Subject : Re: [M100] 19.2Kbps on the Tandy 102 > > > >Wow Brian! > > > >This setup with the Pi attached to the back looks amazing. It's attached > >so cleanly as well. I appreciate you doing the `stty' at the end, > >hopefully mirroring your setup will help me get things working better on > >my end. > > > >I do wonder if the fact that you are using the Pi's GPIO pins to do > >serial instead of a USB adapter is part of why your system is working so > >well. If you have a USB adapter floating around, I'd be really curious > >if you got the same results with that connected to the PI instead of > >connecting it directly. > > > >Thanks again for sharing your experience getting this working. > > > >On Tue, Dec 12, 2023 at 05:42:28PM -0500, Brian Brindle wrote: > >> This has come up in discussion a few times so I wanted to show that > >> 19.2Kbps on the Tandy 100 is possible with only software flow > control. > >> > >> Here is a video of me creating a 500 line 40 col file that is 20KB, > >> transferring it to the M102 and back again using the 19.2Kbps serial > >> connection. It gets slowed down due to the screen being so slow > making > >> it absolutely of no value to be running at those speeds but does > >> demonstrate that flow control can be used on a Linux device in this > >> situation. > >> > >> Hardware flow control would work best and is what I would recommend > but > >> I wanted a device that would work on a stock M100/102 and on a M200 > >> where the flow control lines do not work properly. > >> > >> It's apparently really hard to film, type and remember what to say > so I > >> apologize for that.. > >> > >> [1]https://youtu.be/BGxx__Zr1O4 > >> > >> Brian > >> > >> References > >> > >> 1. https://youtu.be/BGxx__Zr1O4 > > >
