The era of the vintage television was a great one, and one of the transitional by-products was the Sony Watchman. It was a portable TV which Sony started selling in 1982, and the amazing thing about it was that it had an actual 4-inch cathode ray tube or CRT. [Sideburn] just posted a video in which he hijacks the internals of a Watchman to make it into a portable game of Pong.
The hack begins with removing the TV tuner module inside to make some room for the new residents. Next comes the M51364P which is VIF video decoder chip, and for which surprisingly there is not a lot of info on the web. They were able to find a part of the schematic, which though it was in Russian may still be useful for enthusiasts. Removing the VIF revealed the audio and video pins that needed the appropriate signals for the hack to be successful. In an age of multilayer boards it is amazing how a two-layer PCB makes life so easier for the tinkerer.
For the new brains an Arduino Nano clone was selected, and instead of adding modern buttons the existing volume and band select switches were convinced to be the paddle control and play/pause button. Getting everything to fit was easy with the absence of the tuner module, and voila! New(ish) hardware. For the firmware, [Sideburn] turns to Hackvision firmware which has a host of games such as Space Invaders, Asteroids, and even Tetris.
We covered Hackvision a few years ago as a hardware/firmware bundle, and if you are more into CRTs then check out the Arduino driven 6845 CRT controller.
10 thoughts on “Hijacking A Sony Watchman For Pong”
great now the price of watchman’s will go up in price on e-bay.
wow what was i thinking when i typed this…….great now the price of watchmans will go up on e-bay
Cool, I’m currently implanting a Pi Zero W into an old Nordmende TR101. Video signal injection works the same way: at the output of the VIF. Because I have the complete schematics, I was able to remove more than half of the original electronics (all of the receiving circuitry, and the complete FM radio board, which I intend to replace with a small digital FM board)
I was worried that I would need a sync separator, but the FBAS output of the Pi worked as it is.
Wasn’t the Sinclair portable CRT TV electrostatically deflected like an old oscilloscope? That would probably be better for those looking to make a vector display.
Gosh I’m working since few weeks on the same project be with a color display. Talk about being burned! Great implementation anyway!
You’re not burned! We’d like to see yours too. (firstname.lastname@example.org)
On the VIF chip, I kind of cheated I the video and article it’s an M51364P but I took that picture from a different model watchman. The chip in the fd-20a is a Sony chip and there is no info on it online that I could find so I just took a guess that it was the VIF chip and pulled it out and then probed around until I found the video and audio outputs.
Thanks for the article!
got a pinout? I am looking to do something similar.
I should get back onto my project of pulling a 5″ colour CRT from a ‘TV The Searcher’ boombox / TV combo from the 80’s.
I just need a slightly uncommon TI opamp to build a level shifter to lift the composite video signal by about half a volt or so, so there is no negative going pulses.
The video processor chip seems to dislike negative going waveforms, I think it is to help simplify design and cost by eliminating the need for a dual rail power supply.
Oh, then I need to stick it in an enclosure, maybe….
I bought one of these at a thrift store a couple of years ago meaning to do something cool with it, and it’s been sitting near the top of my junk pile ever since. Seeing this project finally gave me the motivation to cobble together some adapters to run an Atari video connection into the aux antenna port. Now I too can play Pong, albeit with a chunky controller and still plugged into the wall.
As a bonus, using a 2″ television as a display gives a new meaning to TRS-80 Micro Painter!
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