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Thread: CIT-101 terminal

  1. #21

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    Incoming pictures and ROM dump!

    http://binarydinosaurs.co.uk/C.Itoh-CT101keyboard-1.jpg
    http://binarydinosaurs.co.uk/C.Itoh-CT101keyboard-2.jpg
    http://binarydinosaurs.co.uk/C.Itoh-CT101keyboard-3.jpg
    http://binarydinosaurs.co.uk/C.Itoh-CT101keyboard-4.jpg
    http://binarydinosaurs.co.uk/C.Itoh-CT101keyboard-5.jpg

    http://binarydinosaurs.co.uk/cItoh-CT101keyboard.bin

    Mike, I priced up shipping a small keyboard to Seattle yesterday in a 42x18x18 box and it was going to cost around $30 in shipping alone so a box big enough for one or both of these keyboards would be at least double that, but it's easy to have things picked up from work if I can find a box big enough. No idea what they're worth or even if they work!
    www.binarydinosaurs.co.uk - UK home computer history
    Where RIFA capacitors come to die
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  2. #22
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    I sent you a PM. Mike

  3. #23
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    I've been busy working at my daughters new home. Time has been spent sloshing paint, swinging a hammer, ripping up and laying down carpet and many other exercises that I have not done for a while. All resulting in my muscles letting me know I'm not a young as I once was. My daughters home is more than an hour from my house and this has prevented me from much work on the CIT terminal. Yet I have found that the CIT-101 monitor seems to communicate with the keyboard, via 5 volt signals. The VT-100 manuals describe a 6 volt piggy back signal (12 volt) communications format. I removed the circuit board from the monitor and attempted to trace the keyboard plug wires onto the CB. Looks like the signal wire is connected to 5 volt chips, with no 12 volt supply near. The CB is rather high density and the traces jump from front to back sides many times. This makes tracing out the circuit a little difficult. It would be great to have a schematic. Using the Arduino I captured the data the monitor was sending to the keyboard. The monitor is sending a repeating sequence of two data bytes. The first I am guessing is the status byte, then an end of scan byte. These bytes appear correct. The status byte appears to have a start scan bit set and all the LED signals are set. The end of scan byte, according to the VT-100 documentation is 7Fh, yet the byte sent by the CIT monitor is 5Fh. This is a little confusing. Thanks Mike

  4. #24
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    I'm still putting in time at my daughters new house. AND she has not moved yet. More to come. I've been communicating with Witchy regarding these keyboards. He has tried the CIT keyboards with a VT100 monitor and found that they do not work. So.... either both keyboards are bad or the CIT keyboard will not work with a VT100 monitor. I'm currently leaning toward the later. Anyway, we have made a deal on the keyboards and they are in the post making their way from England to the States. Maybe next week they could be here. Hopefully one will work and I can get a better understanding of how the CIT communication between the keyboard and monitor works. I'd still like to fashion an Arduino into a keyboard substitute. Mike

  5. #25
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    Last month, Witchy and I made a deal on his keyboards. After some discussion regarding shipping etal., the keyboard package was posted and started out on a circuitous path from the UK to my house. The shipper provided tracking. I anxiously watched this most every day until the keyboards arrived. I found it very interesting how and where the package was and how long it stayed there.

    13/04/2019 - 14:55 Package delivered to destination Location: New Berlin, WI
    13/04/2019 - 08:40 USPS out for delivery Location: New Berlin, WI
    13/04/2019 - 08:30 Enroute Arrived Location: New Berlin, WI
    12/04/2019 - 16:51 Arrival at Delivery Unit Location: New Berlin, WI
    12/04/2019 - 15:36 Arrival at Delivery Unit Location: New Berlin, WI
    11/04/2019 - 22:36 Departing Facility Location: Carol Stream, IL
    10/04/2019 - 20:33 Arrived at Facility Location: Carol Stream, IL
    10/04/2019 - 13:37 Departing Facility Location: Greenwood, IN
    10/04/2019 - 12:30 Enroute Arrived Location: Greenwood, IN
    09/04/2019 - 16:30 Departing Facility Location: Elizabeth, NJ
    09/04/2019 - 14:00 Enroute Arrived Location: Elizabeth, NJ
    09/04/2019 - 10:30 Enroute Arrived Location: Elizabeth, NJ
    09/04/2019 - 07:22 Inducted into Network Location: Elizabeth, NJ
    08/04/2019 - 23:52 Accepted in-country hub Location: NEW YORK
    08/04/2019 - 15:23 Parcel Cleared US Customs Location: World Container JFK CFS
    03/04/2019 - 03:46 Data manifested/received Location: Inwood, NY
    03/04/2019 - 02:35 Parcel scanned at UK inbound facility Location: London
    02/04/2019 - 00:42 Crossing border and in transit to carrier hub Location: Heston, MIDDX
    02/04/2019 - 00:40 Transmitted customs information Location: Heston, MIDDX
    02/04/2019 - 00:28 Grouped when pallet scanned to crossing (WNS JFK 4) Location: Heston, MIDDX
    01/04/2019 - 17:37 Scanned at Landmark crossdock facility Location: Heston, MIDDX
    01/04/2019 - 15:45 Processed Location: Heston, MIDDX
    27/03/2019 - 08:50 Shipment Data Uploaded Location: Heston, MIDDX

    All in all 18 days pasted while this package sat in one dept. or other. Anyway, it is here and I'll be opening it up soon to see what I actually obtained. Thanks, Mike

  6. #26

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    Glad to see they arrived safely! I'm looking forward to seeing them mated to their correct terminal
    www.binarydinosaurs.co.uk - UK home computer history
    Where RIFA capacitors come to die
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  7. #27
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    You did a great job of packaging up these keyboards. There was no signs of trauma on the box or internally at all. And the keyboards appear just as in your pictures. Hope to get to these little gems soon. Thanks Mike

  8. #28
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    Well..... today I found some time to look at the two keyboards I have just received. Both look the same, although one has had it's coiled cord replaced at one time. There is no corporate logo on either case any where on the outside. I did find a shadow of some writing, University of York Pysch Dept. On the bottom of each case there is a paper tag with what could be a serial number. The case is split into an upper half and lower half by four small screws. Inside there is also no corporate logo or information. I did find on the back of the circuit board C-ITOH and some numbers. One keyboard is missing 5 key caps and three of those switches have the actuating post broken off. I wonder if these keycap and switches are similar to the DEC VT-100? I popped all the keycaps off with no trouble and cleaned them. I also cleaned the upper and lower halves of the cases and cleaned the circuit board and key plate. Quite a lot of dust, hair and dirt. Actually it all cleaned up quite well. Looking at the circuitry, both seem exactly the same. There are only 10 IC's

    IC1 74LS244
    IC2 74LS374
    IC3 74LS373
    IC4 2716
    IC5 8048
    IC6 7407
    IC7 7407
    IC8 NE555
    IC9 75452
    IC10 7805

    Looks like a 8048 CPU and 2716 external memory and a bunch of buffers. Later, I'll try to trace out some the circuit. I figure I'll fire up one of the keyboards tomorrow. I'll pull out the chips in sockets and use a variable power supply to build up the 12 volt supply. Hopefully I will not let any smoke out the wiring.

    IMG_0016.jpg
    Dirty
    IMG_0021.jpg
    Keycap off. Here you can see the chips
    IMG_0019.jpg
    Corporate Logo C-ITOH on CB
    IMG_0015.jpg
    Cleaned up pretty good!

  9. #29

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    Thanks re: packing, I always anticipate Bad Things happening to parcels so pack accordingly. I'm SO looking forward to seeing these working!
    www.binarydinosaurs.co.uk - UK home computer history
    Where RIFA capacitors come to die
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  10. #30
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    Today, again, I only found a little time to spend on the keyboards, but progress was made. The actions I'm about to mention I applied to each keyboard. First I lifted the 7805 regulator and replaced the thermo grease under them. The CPU and external memory 2716 chips were popped out. I then applied a variable DC to the +12 jack pins. I watched the input current and the output voltage of the 7805 as the voltage was increased to 12 volts. No problem with either keyboard. Next the CPU and 2716 were replaced and the voltage was applied again, no problems. Now the keyboards were connected to the Monitor. When the monitor was turned on, the keyboard beeped and the off line LED lit. Then about 3 seconds later, the keyboard beeped again and the on line LED was lit. So far so good. I connected the Tx to the Rx of the RS232 D connector. Then typing the letters and number produced text on the screen. I found that there is 8 switches that do not work, but each function does work. I proved this by shorting the back of the CB for these switches. I may try some contact cleaner, after I see whether or not there is a place for it to be applied. There are three other switches that are questionable. Sometimes they work and sometimes not. One switch must have loose parts in it. I can hear a rattle and once in a while that key will start to repeat it's letter as if the key was held down. The Set UP key also works and some of the function of Set Up. I have to reread the User's Manual to re-familiarize myself with how these functions work. So far I can not tell if the key switches have any ID markings on them. I suppose I'll have to use switches from one keyboard to make one good one. I first want to determine which keyboard is the better one. I want to connect this Monitor up to my ASR33 to see if the RS232 interface will drive it. Maybe tomorrow or this week end. Now I have some User Manual reading to catch up on. Mike

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