VT100 Terminal question

[John5528]

Hi all that reads,

I have bought an ANSI VT100 / VT52 RS232 Serial Terminal Project Kit , running with a Pi Pico. It seems to be happy to start, allow me to use VGA/keyboard to mess with it's settings etc. I have it wired directly to RS232-1, and have the on-board jumpers installed as per the documentation - config for baud rate matches on boot.conf (UART0=115200,cs8) and the VT100 Terminal device - yet I get exactly 0 output. I am making sure that the web page is not active, as I know that it doesn't like to share - I have changed between null modem and straight through (just in case the project board is hardwired Null-Modem.

Not a peep on the display. Any ideas? Or anything I can do to test?

[ronaldlw]

To be clear, this is some other vt100 serial terminal? not the VT132 or s-132 boards from the high nibble?

It would be good if you could post the actual jumper settings, preferably with pictures showing how they are set.

What kind of test equipment do you have, if any? I.e. multi-meter, oscilloscope, etc?

do you have a usb to rs-232 adapter that you can try to connect to your computer for testing?

[John5528]

Hi - thanks for the response.

No, not the VT132 or S-132 (although I am in the process of populating that board right now). This is a VT-100 terminal plugged in via serial cable.

I've enclosed the jumper settings picture, along with the terminal settings (screen pic). boot.conf is set:

UART configuration

UART0=9600,cs8
UART1=9600,cs8

I have a multimeter, but no oscilloscope. I may order a rs-232/usb adapter to test.

Again, thanks for your reply

[ronaldlw]

So jumpers look ok

I don't have the baud setting configured in my boot.conf, probably because I'm using 115200, cs8 on my VT132 console, which I believe is default setting for the IMSAI.

The boot.conf should also be where you add the UART0 to the SIO1 settings like this:
SIO1.portA.device=WEBTTY+,UART0

For me, this allows accessing the console from both the web interface and the serial port at the same time (the docs say this doesn't work, but it does for me)

Once you get this working, you might want to switch to UART1. The debug output all goes to UART0 and you can't disable it. For me this detracted from the illusion that I have a real IMSAI 8080 and a real VT100 terminal :)

[ronaldlw]

According to the docs the default should be
SI01.portA= WEBTTY UART0
But if i comment out SI01 my VT132 doesn't get any output, the same as what you are seeing. So I'm guessing either the default value is wrong (because what is reference elsewhere in the default boot.conf file show on the document page has the .device added to the parameter) or the default is actually different (i.e. just WEBTTY and not UART0)

Very confusing :)

[John5528]

We love confusion! :-)
I'll take a look at the settings again, I think it was as you said above, but now that I've built the S-132, I'm moving my confusion there for now. Seems that I have a terminal working....but the output is odd. Every day is a school day.

Thanks once more for helping, I'm picking things up I hadn't thought about - it's been really helpful.

[ronaldlw]

Awesome, just so you know, you should be able to hook up a monitor to the S-132 as well as a terminal to the IMSAI (like you've been trying to do). I have both and I'm able to use the webtty, the S-132 output and a VT-132 console all at the same time.

[John5528]

I may try that too - I read your post on it. Right now, I'd be glad to get either option working (see my new noob post for details!). ;-)