This project was my first video bending attempt. I’ve been on the lookout for a visual/vid machine to work on and my luck was in when I found the SONY xv-t33f.
The xv-t33f was originally released in the early 90’s as a device to add custom titles to home videos. It has a touch tablet for drawing and various touch buttons for colour changing, brush thickness, circle and square drawing, type entry and a menu button which allows the user to select various pre-drawn and rather cheesy shapes (christmas trees and birthday cakes etc). To draw you press a plastic stylus on the tablet whilst holding down the ‘draw’ button. Once happy with your artistic efforts you can scroll them across the screen like film titles with a video input playing underneath.
After a quick doodle or two I unscrewed the case and started investigating the innards of the machine. Now for an important point. This device is not a battery operated toy, it is mains powered. Touching the wrong part of the internal circuit can result in a serious electric shock. Luckily for us, the mains power is converted inside the machine by a small transformer circuit as pictured below. Avoid going anywhere near this area.
Ok, back to the fun stuff. There are a number of IC’s inside but my attention was drawn to the three biggest. These are:
- Yamaha V9938
- Sony LH534HSY
- Zilog Z0840004PSC CPU
The sony is probably for video overlay (not all that much info on this one) and the yamaha chip is the heart of painting part of the machine, a ‘video display processor’. The zilog chip is the CPU. In my experience of bending, it’s generally advisable to avoid fiddling with CPU chips. Doing so nearly aways ends in crashing the machine or locking it up and indeed, this was the case with the zilog. So, my bending efforts were centred around the yamaha VDP or the sony chip.
After some probing around I found very little of interest on the sony chip whereas the yamaha was full of glitching and colour changing bend potenial. There were too many bends to be able to mount controls on the existing housing of the xv-t33f so i decided to make an external controller. The list below shows the bendable chip pins I have wired up along with the components I used to connect them. Most of the other pins would result in a reset or lockup. Sony were kind enough to mark the pin numbers on the circuit board so you should find this list easy to use.
The external controller contains the following components:
Six toggle switches connected to the following pins:
- pins 4 + 20 — a picture twisting horizontal hold mashup effect
- pins 8 + 23 — pink/orange colour change
- pins 10 + 23 — a black on orange silhouette effect
- pins 19 + 22 — neon green effect
- pins 19 + 23 — neon orange effect
- pins 20 + 22 — purple/red colour change
A 20 point patch bay using mini jack sockets connected to the following pins:
- 41 to 61 — glitching, noise, mirroring and crazy data mashups.
I connected the controller to the xv-t33f using a 37-way d-sub plug and socket. This is so the bending controller can be disconnected for ease of transport.
If attempting these bends I would suggest you unscrew the circuit board containing the yamaha v9938 chip and solder the wiring to the leg pins on the underside. there is plenty of room for the wires to sit when the board is reseated and the internal wiring looks a little neater when you reasemble the machine.
The xv-t33f is now a fantastic video glitch machine, ideal for live VJ’ing or animation creation. Here’s an example of some of the effects possible when using the new bend controller:
20/03/2007 at 9:44 pm Permalink
rather wonderful
26/05/2007 at 7:42 pm Permalink
crea bea