🚀 go-pugleaf

As one of those animation wannabes who doesn't have much money,
I have been trying to get my povray animations onto video tape.

To this end, I have been trying to 'trick' my sony slv696 vhs vcr
into doing 'single frame' recording.  I have had some success, so
I thought I would post my methods of madness in case anybody wants
to try this.

I currently have a 386 clone, a sony slv-696 vcr, some home brew
control-S circuitry and code, an old soundblaster with the midi
option and a cheap MIDI timecode generator/reader I bought used
for $40.

What I do is to record video black (from my trusty commodore64) and
time code onto a blank vhs tape.  I use an old shareware midi sequencer
program to generate the midi clocks that go into the timecode box.
I have found that it is best to record about 10sec of silence, then
turn on the timecode box to get about 10sec of 'carrier' tone, then
I start the sequencer running to put the actual timecode on the tape.

Next I swap around the connections so the audio track of the vcr is
fed into the timecode box.  The midi out of the timecode box goes into
the soundblaster.

Now I startup my handy-dandy borland c hack that commands the vcr to
rewind (via the serial control-s jack).  After a 10sec time delay to
let the tape rewind, the deck is put into play mode.  Now the software
sits and polls the soundblaster until the first timecode byte comes in,
then sends a pause command to the vcr.  Next, frame advance commands are
sent to the deck to get to the desired frame.  Now the deck is put into
record mode, the desired video picture is fed into the VCR and the deck is
unpaused.  About a second of video is recorded, then the process repeats.
I manage to get about 2 1/2 seconds of video recorded per hour (90 frames).

This seems to work pretty well, although it is not always right on the money.
For every second of video (30 frames), usually there are one or two places
where two frames get recorded instead of one.  I'm not sure how this affects
the final video, because I don't have a VGA->NTSC converter yet and hav only
recorded test frames.  Hopefully this will have a minimal impact on the
final video.

If anybody wants to try this, email me and I will give you the details of
the pieces and parts and where to get stuff.

Martan