5 Jan
2026
5 Jan
'26
9:10 p.m.
I inherited a C. Itoh CIT-220 with no keyboard. Is the keyboard model-
or C. Itoh-specific or will other keyboards work with it?
alan
6 Jan
6 Jan
5:56 a.m.
good question. I have a CIT-101 which is the VT-101 clone. I never
tried swapping keyboards but it sure looks identical to any DEC
keyboard. If I was to bet based on what I have I'd say yes, any DEC
keyboard compatible with a vt-220 would work in the CIT. I think that
was their business model back then, I used to know a guy who bought
used DEC terminals and replaced them with new CIT's (I think it was
CIT), and then sold the used DEC terminals to companies in the used
DEC hardware market. Pretty slick business model IIRC.
My CIT-101 came from a Commodore employee, I live near there and one
of their engineers used this terminal, but no one "famous".
I don't have any other CIT terminals. Sark in the vcf forums would know.
Bill
On Tue, Jan 6, 2026 at 12:15 AM Alan Perry via cctalk
<cctalk(a)classiccmp.org> wrote:
I inherited a C. Itoh CIT-220 with no keyboard. Is the keyboard model-
or C. Itoh-specific or will other keyboards work with it?
alan
6:08 a.m.
Correction - I did have a CIT-220, and now I remember that the
keyboard is not a drop in replacement. So I take back my previous
statement. Here is a picture I found but I don't have a picture of
it attached to the DEC Workstation it came with.
https://www.vintagecomputer.net/pictures/2018/Snyder/CIT_220plus.JPG
Bill
On Tue, Jan 6, 2026 at 8:56 AM Bill Degnan <billdegnan(a)gmail.com> wrote:
good question. I have a CIT-101 which is the VT-101 clone. I never
tried swapping keyboards but it sure looks identical to any DEC
keyboard. If I was to bet based on what I have I'd say yes, any DEC
keyboard compatible with a vt-220 would work in the CIT. I think that
was their business model back then, I used to know a guy who bought
used DEC terminals and replaced them with new CIT's (I think it was
CIT), and then sold the used DEC terminals to companies in the used
DEC hardware market. Pretty slick business model IIRC.
My CIT-101 came from a Commodore employee, I live near there and one
of their engineers used this terminal, but no one "famous".
I don't have any other CIT terminals. Sark in the vcf forums would know.
Bill
On Tue, Jan 6, 2026 at 12:15 AM Alan Perry via cctalk
<cctalk(a)classiccmp.org> wrote:
>
>
> I inherited a C. Itoh CIT-220 with no keyboard. Is the keyboard model-
> or C. Itoh-specific or will other keyboards work with it?
>
> alan
>
>
11:46 a.m.
On Tue, Jan 6, 2026 at 8:57 AM Bill Degnan via cctalk
<cctalk(a)classiccmp.org> wrote:
good question. I have a CIT-101 which is the VT-101
clone. I never
tried swapping keyboards but it sure looks identical to any DEC
keyboard.
We had CIT-101 and CIT-101e terminals at work in the 80s/90s. They
use the same type of 1/4" connector as a VT100 but are not
cross-compatible. I still have a couple of CIT-101 terminals from
those days but I packed the box of keyboards away when we moved and
they haven't ever turned up (I do have a working CIT-101e w/keyboard
and have brought one to VCF East and Midwest). They do look the same
externally but don't generate any key events when tried. IIRC nothing
breaks from connecting the wrong keyboard, but you just don't get key
events.
I do not know anything about the CIT-220 but at least by the VT220
era, the physical connection was just a pretty plain async serial link
(not the bidirectional whatever the VT100 used). There are modern
microcontroller adapters for VT220s. Seems like they might make a good
starting point for a CIT-220 keyboard adapter.
-ethan
8:16 p.m.
On Tue, Jan 6, 2026 at 2:47 PM Ethan Dicks via cctalk
<cctalk(a)classiccmp.org> wrote:
IIRC nothing
breaks from connecting the wrong keyboard, but you just don't get key
events.
I can't remember if I went CIT keyboard -> VT100 or VT100 keyboard ->
CIT-101 but I do remember it literally blew up some small DIP in the
keyboard. Luckily I just had to replace the DIP, whatever it was, and
all was well.
Jim
8:51 p.m.
On Tue, Jan 6, 2026 at 11:16 PM Jim Carpenter via cctalk
<cctalk(a)classiccmp.org> wrote:
On Tue, Jan 6, 2026 at 2:47 PM Ethan Dicks via cctalk
<cctalk(a)classiccmp.org> wrote:
Ah. I don't remember which way I went either, and not crossing the
streams is obviously safer than mixing vendors like that.
-ethan
IIRC nothing
breaks from connecting the wrong keyboard, but you just don't get key
events.
I can't remember if I went CIT keyboard -> VT100 or VT100 keyboard ->
CIT-101 but I do remember it literally blew up some small DIP in the
keyboard. Luckily I just had to replace the DIP, whatever it was, and
all was well. 
7 Jan
7 Jan
9:47 a.m.
In article <ab1dea3f-947a-4813-8cad-b57057af2c7d(a)snowmoose.com> you write:
I inherited a C. Itoh CIT-220 with no keyboard. Is the
keyboard model-
or C. Itoh-specific or will other keyboards work with it?
By the time we get to the VT 220 and clones, it's likely that there's
a microcontroller inside the keyboard that is doing the communication
with the main unit. Typically the communication is 1200 baud serial
bit stream with unknown contents.
I would try an LK-201 keyboard, the keyboard used with the VT 220. I
am not aware of any service manual (or even a user manual!) for this
terminal.
If you're really paranoid about damaging either the keyboard or the
terminal, you should use a voltmeter to identify which pins on the
connector are power and ground and make sure that they both the keyboard
you're going to try and the terminal agree on which pins are used for
power and ground. The remaining pins are going to be the serial transmit
and receive, likely at TTL levels not RS-232 levels.
There's a possibility of damage if power and ground are misconnected
but little chance of damage if it's just the receive and transmit that
are misconnected.
Hope that helps. Everything I know about this terminal is here:
<https://terminals-wiki.org/wiki/index.php/C._Itoh_CIT-220>
--
"The Direct3D Graphics Pipeline" free book
<http://tinyurl.com/d3d-pipeline>
The Terminals Wiki <http://terminals-wiki.org>
The Computer Graphics Museum <http://computergraphicsmuseum.org>
Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>
11:03 a.m.
Repeating from my earlier response. The CIT220 keyboard is NOT
compatible with the VT220's. You'd have to wire up a patch adapter.
I don't remember who I sold my CIT220 to last year and I could not
find a picture to show that the keyboard adapters are different.
Bill
On Wed, Jan 7, 2026 at 1:55 PM Richard via cctalk <cctalk(a)classiccmp.org> wrote:
In article <ab1dea3f-947a-4813-8cad-b57057af2c7d(a)snowmoose.com> you write:
I inherited a C. Itoh CIT-220 with no keyboard. Is
the keyboard model-
or C. Itoh-specific or will other keyboards work with it?
By the time we get to the VT 220 and clones, it's likely that there's
a microcontroller inside the keyboard that is doing the communication
with the main unit. Typically the communication is 1200 baud serial
bit stream with unknown contents.
I would try an LK-201 keyboard, the keyboard used with the VT 220. I
am not aware of any service manual (or even a user manual!) for this
terminal.
If you're really paranoid about damaging either the keyboard or the
terminal, you should use a voltmeter to identify which pins on the
connector are power and ground and make sure that they both the keyboard
you're going to try and the terminal agree on which pins are used for
power and ground. The remaining pins are going to be the serial transmit
and receive, likely at TTL levels not RS-232 levels.
There's a possibility of damage if power and ground are misconnected
but little chance of damage if it's just the receive and transmit that
are misconnected.
Hope that helps. Everything I know about this terminal is here:
<https://terminals-wiki.org/wiki/index.php/C._Itoh_CIT-220>
--
"The Direct3D Graphics Pipeline" free book
<http://tinyurl.com/d3d-pipeline>
The Terminals Wiki <http://terminals-wiki.org>
The Computer Graphics Museum <http://computergraphicsmuseum.org>
Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>
1:12 p.m.
In article <CABGJBudDLosOXhYHtzj7oO4WqDJ93xw8AH=fLTXaqC5JXL83fw(a)mail.gmail.com> you
write:
Repeating from my earlier response. The CIT220
keyboard is NOT
compatible with the VT220's.
Noted on the C. Itoh CIT-220 terminals wiki page with a link to your
post in the cctalk archives :)
--
"The Direct3D Graphics Pipeline" free book
<http://tinyurl.com/d3d-pipeline>
The Terminals Wiki <http://terminals-wiki.org>
The Computer Graphics Museum <http://computergraphicsmuseum.org>
Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>
11:12 a.m.
On Jan 7, 2026, at 12:47 PM, Richard via cctalk
<cctalk(a)classiccmp.org> wrote:
In article <ab1dea3f-947a-4813-8cad-b57057af2c7d(a)snowmoose.com> you write:
The LK201 indeed has a microcontroller inside. It communicates via serial communication,
8 bit UART at 4800 baud, RS232 levels. The protocol is fully documented in the Pro 300
Technical Manual (on Bitsavers).
If the C.Itoh terminal uses that same interface, one option if you don't have or
don't want to use an LK201 is to use one of the two LK201 emulators I designed (one
for a PS-2 style keyboard, one for a USB keyboard). Both use small Arduino controllers;
the design is open (code, circuit, PCB) at https://github.com/pkoning2/lk201emu .
paul
I inherited a C. Itoh CIT-220 with no keyboard.
Is the keyboard model-
or C. Itoh-specific or will other keyboards work with it?
By the time we get to the VT 220 and clones, it's likely that there's
a microcontroller inside the keyboard that is doing the communication
with the main unit. Typically the communication is 1200 baud serial
bit stream with unknown contents.
I would try an LK-201 keyboard, the keyboard used with the VT 220. I
am not aware of any service manual (or even a user manual!) for this
terminal.
1:05 p.m.
In article <52D03E09-A6D5-46D4-9304-04C3C993F46E(a)comcast.net>et>,
Paul Koning <paulkoning(a)comcast.net> writes:
I designed (one for a PS-2 style keyboard, one for a
USB keyboard). Both
use small Arduino controllers; the design is open (code, circuit, PCB) at
https://github.com/pkoning2/lk201emu .
Hey, that's great! I've linked to it from the VT220 terminals wiki page.
<https://terminals-wiki.org/wiki/index.php/DEC_VT220>
--
"The Direct3D Graphics Pipeline" free book
<http://tinyurl.com/d3d-pipeline>
The Terminals Wiki <http://terminals-wiki.org>
The Computer Graphics Museum <http://ComputerGraphicsMuseum.org>
Legalize Adulthood! (my blog) <http://LegalizeAdulthood.wordpress.com>
11:20 a.m.
On Jan 7, 2026, at 12:47 PM, Richard via cctalk
<cctalk(a)classiccmp.org> wrote:
...
If you're really paranoid about damaging either the keyboard or the
terminal, you should use a voltmeter to identify which pins on the
connector are power and ground and make sure that they both the keyboard
you're going to try and the terminal agree on which pins are used for
power and ground. The remaining pins are going to be the serial transmit
and receive, likely at TTL levels not RS-232 levels.
I have no idea about non-DEC terminals, but the LK201 uses real RS232 levels. Those are
bipolar (plus or minus 5 volts or more) and if you connect that to a device with a TTL
input it may be unhappy. Typical TTL level logic devices object to negative input
voltages more than 1/2 volt or so.
You could look for the output pin on the keyboard connector of the terminal, ideally with
an oscilloscope at power up because it's likely to send some setup sequence. If you
see +/- 5 volt or so signaling, that would be RS232. If it swings between 0 and 4-ish
volts it's TTL and an LK201 would not work. You could use an RS232 transceiver chip
to convert the signal levels, that's easy. Or take my LK201 emulator with the RS232
transceiver omitted and replaced by a few jumper wires.
paul
9 Jan
9 Jan
2:39 p.m.
On 1/7/26 11:47, Richard via cctalk wrote:
In article
<ab1dea3f-947a-4813-8cad-b57057af2c7d(a)snowmoose.com> you write:
<snip>
C Itoh got into a huge fight with their printers which had copied the
method Printronix used for their shuttle mechanism balance that they
were very wary of doing anything that could be construed as infringement.
The corporate made up a batch of about 1000 clones to start the line and
it was internally called the ANT. The Japan engineering did everything
to their own ends and there wasn't much other than the use of the escape
codes adopted out of the box for the ANT. They wanted some sort of
"smart" protocol, and used the Vt100 and later Ansi codes.
The US division got about 200 of the original run and I got them
adapters for their RS232 ports. The run had used the wrong "sex" DB-25
and marketing thought they'd not sell w/o offering an adapter.
I bought 2000 of them for the guys and shipped them over (Irvine, CA).
When the division was shut down 4 years later they'd shipped 2 of them,
and I got them all back and sold them back to the Taiwan supplier I'd
originally bought them from.
fun stuff.
Later terminals had the right DB25 sex and didn't need the adapters.
Jim
I inherited a C. Itoh CIT-220 with no keyboard.
Is the keyboard model-
or C. Itoh-specific or will other keyboards work with it?
By the time we get to
the VT 220 and clones, it's likely that there's
a microcontroller inside the keyboard that is doing the communication
with the main unit. Typically the communication is 1200 baud serial
bit stream with unknown contents.
2
days inactive
5
days old
12 comments
7 participants
participants (7)
-
Alan Perry -
Bill Degnan -
Ethan Dicks -
Jim Carpenter -
jim stephens -
Paul Koning -
Richard