🇺🇸 Texas Instruments TI 99/4A: Part 2 (Peripherals & NTSC Composite Video Output) [TCE #0534]
27Continuing on from Part 1 [TCE #0533], let's look at the peripherals for the 99/4A and make up an NTSC composite A/V cable. Unfortunately I followed the wrong pin numbering so ended up with no audio - will make another, correct, cable tomorrow.
Part 1:
• 🇺🇸 Texas Instruments TI 99/4A: Part 1...
00:00 ... Bit more about the power supplies (confirming @JVHShack Part 1 comment)
03:25 ... Checking the available peripheral ports
04:05 ... Dual cassette interface (CS1 & CS2)
06:58 ... Dual joysticks
08:40 ... Dismantling a joystick
12:00 ... Atari joystick adaptor
12:40 ... WICO Command Control trackball
13:40 ... Super Sketch
15:20 ... Machine internals
21:30 ... Oh, I've been in here before
24:10 ... Making up a composite video cable
28:01 ... Testing the disassembled machine - NOK
28:25 ... Testing another machine - OK
29:00 ... Congo Bongo (no audio, sorry 🙉 )
30:58 ... Trying the Super Sketch peripheral
32:33 ... Channel outro/thanks
This is where I got the incorrect pin numbering from - the photos of the actual built cable are correct though:
hhttps://www.instructables.com/DIY-TI-994a-Composite-Video-Cable/
NTSC composite video cable pin out (5-pin DIN):
Pin 1 = n/c (12V)
Pin 2 = ground
Pin 3 = audio (mono)
Pin 4 = composite video
Pin 5 = n/c
Alternate power supplies (from Part 1 video):
[1] A replacement power supply that generates the DC voltages directly and has the correct plug. You will need to modify the internal power board to bypass itself totally:
hhttps://www.keelog.com/power-supply/#ti99
[2] Replace the internal power board with something like this that only requires a regulated 12VDC power supply. You can either replace the power socket with a 2.1mm socket or cannibalise the original plug:
hhttps://github.com/dabonetn/ti99psu-replacement
[3] Use a Mean Well GP25A13A-R1B as the power supply and remove the internal PSU board, wiring a 5-pin DIN socket to the internal cabling.
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