TI Silent 700 (Model 703): Part 1
26This little thermal "typewriter" is actually a Data Terminal with an RS232 serial interface.
13:00 ... I finally find the screws!
16:10 ... finally get the top case off
24:30 ... thermal printing mechanism removed
27:55 ... control board removed
29:50 ... main board removed
33:30 ... finally found the rectifier
They were first introduced by Texas Instruments in the 1970s. Other models had built-in acoustic couplers or socket for direct connection to the phone line. This model would've required connecting to a modem.
The reason I got this is because it's specifically mentioned in the manual for the VIC-1011A, the RS232 interface for the Commodore VIC-20 (see p14).
https://archive.org/details/VIC-1011ARS-232CManual/page/n13/mode/2up
I thought it would be an interesting test - planning to connect them directly via a null modem cable ... a Data Terminal Cable (TI part 9932939-0001).
The first issue is that it has a weird power requirement ... a three horizontal pin plug supplying 20VAC. I found some pictures online: the original US power supply included an earth pin. However it looks like its rectified quite early so I should be able to get away with the equivalent as straight DC (i.e. via my bench power supply).
Although ... now that I've read through the maintenance manual ... maybe I do need an AC supply ... ? Of course, RS232 uses ±12V levels ...
The second issue will be obtaining a PET ASCII (aka PETSCII) character set ROM - I believe that is what the cartridge socket is for ... User Interface Module (UIM).
The third issue will be paper ... hopefully just plain fax paper?
Model 703/707 maintenance manual:
https://studylib.net/doc/25629962/2310453-0001-model-703-707-data-terminals-maintenance-man...
Other Videos By The Clueless Engineer
| 2023-02-17 | Правец 8Д (Pravetz 8D): Part 2 (Oric PETSCII Robots) |
| 2023-02-15 | Dragon 32: Part 3 (testing the CoCoSDC) |
| 2023-02-14 | Dragon 32: Part 2 |
| 2023-02-13 | Dragon 32: Part 1 |
| 2023-02-12 | Sony Walkmans: Part 1 |
| 2023-02-11 | TS100 & IronOS |
| 2023-02-10 | Commodore VIC-20: Refurbishing NTSC Serial No. P386173 (Part 3) |
| 2023-02-09 | Электроника Б3-36 (Elektronika B3-36) Calculator |
| 2023-02-08 | Atari 800: Part 4 |
| 2023-02-07 | Quick Look: Sharp PC-1245 Pocket Computer |
| 2023-02-07 | TI Silent 700 (Model 703): Part 1 |
| 2023-02-07 | Atari 800: Part 3 |
| 2023-02-06 | Atari 800: Part 2 |
| 2023-02-05 | Atari 800: Part 1 |
| 2023-02-05 | Tandy CoCo 2: US To AUS Conversion (Part 1) |
| 2023-02-04 | Work in Progress: Getting an 8" Floppy Drive |
| 2023-02-03 | Nokia: N-Gage QD (Part 2) |
| 2023-02-02 | Invicta Supersonic Electronic Master Mind (Part 1) |
| 2023-02-02 | Galaxy Invader 1000 - Making a USB power cable |
| 2023-02-01 | Casio PB-770 & FA-11 Portable Computer (Part 2) |
| 2023-01-31 | Casio PB-770 & FA-11 Portable Computer (Part 1) |