Is this a clone VT100 Keyboard ?

[leaknoil]

I recently picked up this new VT100 keyboard but, I'm not sure what its from. Its doesn't say Digital anywhere on it and has a HOME/CLR key next to the arrow keys that doesn't seem to be on any vt100 pictures I found. Only marking is a sticker with a serial number on the bottom.

Anyone know what it might be from ?

 

[atod]

That looks like what I had on my VT100 before I sold it

 

[RSX11M+]

Yeah, it looks like it also has a REPT key on the lower right too.

I think it's from a CIT-101, a VT100 "class" clone made in Japan back in the day. There were a few such products because the genuine article was not cheap.

Not sure if it's close enough for the keyboard to be "electrically compatible" as a replacement for the original.

Hope that helps.

 

[Chuck(G)]

I liked the C. Itoh terminals more than the "real" DEC product. At least in the case of the VT-220 compatibles, there were many competitors, including Televideo, Tab, Wyse...

 

[leaknoil]

That looks like it. I wonder if its compatible or not.

Yeah, it looks like it also has a REPT key on the lower right too.

I think it's from a CIT-101, a VT100 "class" clone made in Japan back in the day. There were a few such products because the genuine article was not cheap.

Not sure if it's close enough for the keyboard to be "electrically compatible" as a replacement for the original.

Hope that helps.

 

[Tor]

I liked the C. Itoh terminals more than the "real" DEC product. At least in the case of the VT-220 compatibles, there were many competitors, including Televideo, Tab, Wyse...

One thing I found out about the VT220 clones is that they tend to be more restrictive about the quality of the RS-232 signals. I've had to replace a Wyse and another one (which name I can't recall at the moment) with real VT-220's because they wouldn't work as consoles on some computers where the RS-232 interface was apparently hacked together from 5v or something. VT220 worked fine, the clones didn't.

 

[RSX11M+]

One thing I found out about the VT220 clones is that they tend to be more restrictive about the quality of the RS-232 signals. I've had to replace a Wyse and another one (which name I can't recall at the moment) with real VT-220's because they wouldn't work as consoles on some computers where the RS-232 interface was apparently hacked together from 5v or something. VT220 worked fine, the clones didn't.

Gee Tor... I almost forgot about this issue. It's true that many modern implementations of EIA wouldn't meet the needs of devices that adhere to the "strict" standard.

Nowadays, anything lower than -2V or so will satisfy a modern RS-232 receiver as a valid low, but it's not actually correct. So today's, +5 and -5 [made from a charge pump] might not do for older equipments.

 

[RetroHacker_]

CIT keyboards are not compatible with the VT100. That sure looks like one. The CIT keyboard looks almost exactly the same as the VT100's, but it uses a different key switch mechanism. The VT100 uses the large square sliding key switch with the visable contacts. The CIT keyboard uses the more common "little plus" shaped key switch stalks and sealed keyswitches.

-Ian

 

[Chuck(G)]

One thing I found out about the VT220 clones is that they tend to be more restrictive about the quality of the RS-232 signals. I've had to replace a Wyse and another one (which name I can't recall at the moment) with real VT-220's because they wouldn't work as consoles on some computers where the RS-232 interface was apparently hacked together from 5v or something. VT220 worked fine, the clones didn't.

Well, to be perfectly fair, the original idea behind Wyse terminals was that they were cheaper than anything else. Remember the Wyse 50 and the strange way it treated attributes?