ZX81/TS1000/TS1500 composite video board - assembled & tested - FREE ship Canada

Description

This ZX81 video mod board will output a composite video signal with a proper “back porch” so that the output can be viewed on a modern television.  Modern TVs will not display a proper picture using the RF modulator output, and thus require a composite video input.
The board is a modified version of the zx.zigg.net circuit, and can also be used on the Timex Sinclair 1000 and 1500. Can be installed either inside or outside of the RF modulator case (see pictures) - no need to unsolder the RF modulator or disassemble everything!  Just pop off the RF modulator lid, clip a few wires, solder four wires and you’re done.
Minimal soldering skills are required.
Don’t bother building it yourself!  Ready to install, fully assembled and tested.
Detailed installation instructions (PDF) and technical support are included.
These boards are tiny, measuring only 19mm x 28mm, so they fit easily inside the RF modulator box.
Works on UK (PAL) or North American (NTSC) models.  Works for ZX81 Issue 1 or Issue 3 models, and all TS1000 and TS1500.
The video mod circuit is needed for two reasons:
1. The ZX81, TS1000 and TS1500 as designed output an
analog
RF signal (UHF or VHF), which can only be displayed on older TVs, or newer TVs that can accept analog signals.  Most newer TVs only accept
digital
RF signals.
2. Even if your modern TV accepts
analog
RF signals, the signal generated by most ZX81 and TS1000/TS1500 computers do not have a “back porch” included in the signal, so your TV will not be able to set the black level properly.  What results is a picture that is washed out, or has very poor contrast, even with the brightness turned all the way up.  You might see a murky “K” cursor by adjusting brightness and contrast, but it will be far from usable.  Some TVs can’t even display a usable picture with this signal.
The video mod circuit generates a composite video signal which can be fed to the video input of just about every modern TV.  This is the yellow center jack on the back of the TV.
How to tell if your computer has a “back porch”
This board works on computers with or without a back porch signal.  Most ZX81 and TS1000 computers do not generate a back porch.  All TS1500 models generate a back porch.
You can easily tell if your ZX81 or TS1000 generates a back porch by opening it up and reading the part number of the ULA chip.  ULA2C184E is the older, original ULA that does
not
have a back porch, while ULA2C210E is the newer ULA that generates a back porch.  It can be used for either model as detailed in the instructions.
Please indicate in your order comments if you’d like wires attached.  Otherwise, just the board will be shipped, and you can use your own wires.
Canadian orders will ship Canada Post Letterpost, typically 5 business days, no tracking.
US orders will ship Canada Post Small Packets, typically 5-11 business days, no tracking.
Overseas (UK, EU, Australia, Asia) please message me for shipping cost, or place order and I'll invoice you.
If you're in the EU, UK, or Australia and interested in a distributorship, please contact me.  Significant quantity discounts are available.
Thanks for looking!