CT1024 with Cursor Control and KeyboardCT1024 with Cursor Control and Keyboard
I acquired a SWTPC CT-1024 TV Typewriter II that was in poor condition. The main board and the memory board were purchased as bare boards and were assembled with non-standard parts. For example 1/2 watt resistors were used instead of 1/4 watt. The IC sockets were in poor condition. The power transformer was rusted from years of sitting in a storage. The keyboard was an old Keytronics unit.
I had a spare SWTPC KB-5 and power supply so I decided to restore the unit from ground up.
The same week I got this CT-1024 my brother gave me a Metcal Soldering station with tips for unsoldering dip ICs. I stripped the main board of all parts and only lifted a few pads.
I wanted to make a case like those in the original photos so I got a large sheet of 1/16 inch thick aluminum and cut it up on my table saw. Here is the case with the power supply and back panel components.
It took about 6 months but I located a complete set of correct parts for the main board. The TIS58 JFETs were out of production but Art Harrison has a Theremin web site that has details on the SWTPC theremins and replacement transistors. The character generator is hard to find but the one that came with the board was OK. If you needed to make a 2513 character generator, Steve Loboyko has ROM images of the ADM-3 character generators.
Assembled
CT-1024 with Cursor Control Board (JPG 95K)
The serial interface had the wrong Molex connector for the I/O and baud rate switch. The manual says to use a "Molex connector housing that does not have the nylon insulation between the pins." This one had the nylon insulation. Since I have two units and want to be able to swap boards I had to redo the connector. I also had to update the junpers. I wired the RS-232 connector so the terminal look like a modem. You can uses a standard model cable to connect the CT-1024 to your computer.
One page of the display had some intermittent characters so I replaced the 2102 static RAM and fixed that problem.
Serial Interface and Panel
Wiring (84K JPG)
The keyboard had a bad encoder chip but I was able to find an exact replacement (the date codes were only 20 weeks apart.) I am going to make an acrylic plastic case so you can see the parts. The SWTPC original has metal brackets to hold up the keyboard. I used 3/4 inch thick clear plastic. I made a jig so I could safely cut the angled parts. I drilled and tapped the holes for 6-32 screws. I may redo these brackets with shorter holes.
Before I make the acrylic case I am making a wood model. The 3/4 inch thick acrylic for the sides cost about $20 a square foot so a want to use scrap wood first. The sides are 3/4 inch thick and the top is 1/4 inch.
Here is the acrylic case. This was my first project in acrylic and it came out OK. I have another CT-1024 that is restored just like this one so I will make another case or two.
Return to CT-1024 TV Typewriter Page
Michael Holley's SWTPC Collection Home Page
PCB
(JPG 145K)
Case
(JPG 66K)
Keyboard mounting (56K JPG)
Wood
Model for Case
Quarter View
Side View
