David Hansel VersaTerm Issue

[Gabriele Giani]

Hi,
I just built David Hansel's VersaTerm (https://github.com/dhansel/VersaTerm), congratulations David, an amazing project!
I plan to use it combined with my AltairDuino 8800 connected to a USB keyboard (compatible with PS2) and a VGA monitor.
The initial screen and configuration menus work very well. I turn on the Altair in USB mode with putty from a PC and pass the control to the RS232 connection (A6/A7) with the classic configuration parameters (9600 8N1), once I have accepted the switch to the VersaTerm (answering Yes to the question that appears on the VGA monitor), the system enters a loop, the Altair configuration screens appear in random sequence as if the terminal was transmitting random characters to the Altair. Obviously I tried to reset the VersaTerm but I get no improvement. Also the LED on the PICO flashes continuously (so something is passing on the serial BUS).
Can you help me? Do you have any suggestions?
Thank you all

[da...@hansels.net]

I guess the first step would be to diagnose whether the problem is on the VersaTerm side or the AD side.

If you connect the serial port of the AD to a PC running TeraTerm, do you get the same behavior of the AD?

If you connect the serial output of VersaTerm to a PC running TeraTerm, do you see any output in TeraTerm

(do characters you type on the VersaTerm keyboard appear in TeraTerm)?

David

[Gabriele Giani]

Hi David, unfortunately I don't have a PC with a serial port to do the tests you suggest, but I can tell you that I use the AD via serial connection with physical Terminals (eg VT220 and modified Minitel) and it works very well so the problem should be in the VersaTerm (?!?). I tried to upload the FW again on both the PICO and ArduinoDue but without success.
I forgot to tell you that instead of the DC-DC converter I put a simple 7805 with a heat sink, and I power everything with 9VDC, but I don't think it can affect the operation.
I was thinking of trying the version of VersaTerm with only the essential electronics, eliminating the superfluous. If I directly connected the PICO to the A6/A7 germinals and used only VGA and USB I can eliminate:
- RS3232 board
- Diodes and transistors
- buzzer
- a few resistors
In other words I could keep only the PICO, the USB and VGA connector and only the resistors for the VGA and the reset buttons (very useful). To do this I have to keep some of the PICO pins UP or at GND or is it not necessary?
Thanks a lot

Gabriele

[da...@hansels.net]

If the problem really is on the VersaTerm then I'd suspect either the RX/TX pins on the Pi to be at
fault or the level shifter (assuming you are using the RS232 connector on VersaTerm).

It's been a while since I worked on VersaTerm so my memory is a bit foggy but I'm fairly sure

you can pretty much disconnect whatever you want (save VCC) from the Pi and VersaTerm
should still work. You can connect the A6/A7 signals directly to the Pi or you could

connect them to the TTL serial connector on the VersaTerm PCB.

What about connecting VersaTerm to one of your physical terminals to see whether it

keeps outputting data? Also, does the cycling on the AD config screen continue if you

disconnect the keyboard from VersaTerm?

David