Serial terminal emulation help, please? (again...) Answered


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Before you read below, read this:

I've finally gotten around to setting up PuTTY to work with the serial line. Communication is fine, I'm pretty sure I have the baud rate and everything set up correctly, but I still have one problem.

The POS program has a login phase, which works perfectly. However, right after the program itself starts and finishes spitting out its splash screen, copyright information, etc., problems start emerging.

Putty doesn't seem to be rendering formatting correctly, or maybe not at all. Whenever text needs to be highlighted, or there need to be shape characters like ┌, or ┤, all I see in the window is garble like this: ae&ae&ae&ae&. Also, no line breaks are given.

How should I fix this? Should I change a specific setting in PuTTY? Should I be using a different program?

***More information about the original terminal, more specific examples and screen-shots willsupplied shortly.***

Kind-of update: Wait, what? So apparently, those two characters above give the same garble on html as on the terminal. They are supposed to be ASCII characters 218 and 195. Note that these are part of the extended ASCII codes (I just realized that). Does PuTTY have an option support ASCII characters 128 to 255? In the character encoding pane of PuTTY setup, I've tried every encoding available. Do I need to type in a name of an encoding manually?


Is there a part number on the old terminals? PuTTY really only emulates an xterm terminal type, and I'd never heard of a serial character terminal acting like an xterm.

It really sounds like the remote system is expecting a different terminal type, which is similar to, but certainly not identical to an xterm. Could be expecting a DEC VT100, a Wyse something, an IBM something, etc. Is the remote system running a UNIX-like operating system?

1.I'll get the part number shortly.

2.The server the server is super-dumbed-down, so all I can say is that it's running Red Hat Linux Valhalla, Xterm, and iceWM. When accessing the server directly, I see iceWM. When i start up a session from a serial terminal, it says that I'm using Red Hat.

3.Yeah, the terminal is made by IBM. I guess I can't use PuTTY, right?

I happen to have a picture of the front of one of the terminals. It says, "IBM 3151." The login screen reads, "Red Hat Linux releas 7.1 (Valhalla)"

I've put a picture up.


Oh, wow, I can't believe I didn't ever search that on google! I only tried searching numbers found on the back!

Anyway, I learned it emulates these older terminals:
Lear Siegler ADM-3A, ADM-5, ADDS Viewpoint A2, Hazeltine 1500, Televideo TVI-910/910+, TVI-912, TVI-920, TVI-925, TVI-925E, and IBM 3101

I also learned you can get into the setup window by typing ctr+setup

I need to get back to one of those terminals...

I'll post another comment when I find out what the terminal's settings are. Oh, one more thing. HOW DID I NOT EVER GOOGLE THAT!?!?!


I think we've all learned a valuable lesson here today.

Google Is Your Friend


lol, yes, that's that's very true.

:-) On a more serious note, I really hope you're doing notes and pictures as all of this goes along. This is going to make a great "how I did it" Instructable.

Oh, of course! I've already begun writing it, actually. It *does* seem like a nice first 'ible.

Speed: 19200
Bits: 8
Stop Bits: 1
Parity: None
Flow Control: None
Emulating: IBM 3151

I did some research and discovered AlphaCom, which I'm guessing is pretty well known to you guys. works perfectly, and is CHEAP! 25 bucks per license? That's great! In fact, we can sell the terminals for *more money* than we're spending on software. Were actually *profiting* from this!

...Instructable coming soon...


...I still need to set up 5 more terminals, though...

Should be the same. You've done very well. Kudos from a pro.

Xterm and IceWM are irrelevant for the serial terminals, but you're on the right track with seeing how the original terminals are set up.

You might find a software emulator for that exact terminal, or you might find the server-side software can work with more than just IBM terminals.

Or, it may simply be that there's a login file on the account the terminals use that hard-codes the terminal type to the IBM one, and the software would work fine with PuTTY's xterm emulation if the terminal type was set properly. The original authors either hard-coded IBM terminal control characters into their software, or they use termcap and terminfo to ask what the terminal capabilities are, and what characters to send for particular functions. If it's the latter, you have a chance at making it work with PuTTY. If the former, you'll have to find a different emulator that's closer to how the original terminals behave.

Ok, thanks!

I'll put you up as "best answer" after two days of inactivity on this question.