ZX Spectrim 128 +3 composite video output and drive belt replacement

Did some work on ZX Spectrum 128 +3 I have. One thing was I wanted to make it work with small “TFT Color monitor” (for a car rear view). This monitor has a composite video input.

First I tried using CSYNK and GND signals for a composite video input. You get the video but it was terrible quality. It seems that “The 128 ZX Spectrums including the +3 (and +2A, +2B) have audio sound modulated onto the video, which reduces the clarity of the composite signal that is available at the modulator input.”(1).

Then I found this document – “Video fixes and video cables
for all ZX Spectrum 128K models”. There is a chapter on Creating composite video-out on a +2A / +2B / +3:

“Although the ZX Spectrum 128K heat sink model and the grey ZX Spectrum +2 have a composite video-out signal on pin 1 of the RGB connector, the ZX Spectrum +2A, +2B and +3 are missing this feature.
Instead of the composite video signal they have a dangerous 12V on pin 1 that will seriously damage your TV or monitor!
But you can add the composite video signal yourself, with the same fairly simple circuit as that is integrated on the heat sink model and +2.
The steps:
1. First remove the 12V from pin 1 by removing resistor R44 (should be the same for +2A, +2B and +3, and very close to the RGB connector).
2. Add this circuit:”

zx spectrum +3 composite video mod
zx spectrum +3 composite video mod

 

zx-spectrum-rgb-pinout
zx-spectrum-rgb-pinout
Perfect packaging :)
Perfect packaging 🙂

And here is the result:

zx spectrum +3 composite video mod
zx spectrum +3 composite video mod

 

 

Result
Result

 

 

Some notes from The Spectrum Show

Some notes I made watching The Spectrum Show.

New games:

Antiquity Jones 2012 Paul Jenksinson

More Tea Vicar 2012 Cronosoft

Future Looter 2011 Timmy

Alter Ego 2011 RetroSouls

Genesis: Dawn of a new day 2010 RetroWorks

Interesting old games:

Glug Glug 1984 CRL

Ninja Hamster 1987 CRL

Worth remembering:

Arcade Pac-Man emulator for ZX Spectrum

Arcade game designer 2008 Chronosoft

 

Recommended retro ZX Spectrum related Youtube channel

If you are interested in retro computing, especially Sinclair ZX Spectrum computing, I highly recommend Paul Jenkinson The Spectrum Show if you haven’t found it yet.

It is very well made series with a nice structure: news of that era, software comparison, game reviews, new software reviews etc. Highly recommend.