[vcf-midatlantic] VCF East 2021: The World of IBM

Ethan O'Toole telmnstr at 757.org
Fri Aug 27 14:35:03 UTC 2021

> My neighbor back in the 80s worked a route for the local convenience store
> chain when they were also doing the video rental business in store. They
> used a custom shaped metal computer box that was mostly rectangular in
> shape, but with a wedged front, containing an embedded 80x20 (or 40x20)
> character LCD screen.

Not too long ago I picked up a 35mm movie projector (like from a theater.) 
After looking into all the things I need to make it go, I started digging 
into the audio hardware.

There are three digital standards of encoding digital audio on motion 
pictures. One is Dolbu Digital, which optically reads what looks like a QR 
oode printed between sprocket holes. Another is Sony SDDS which reads 
optical digital data left of the sprocket holes and on the right of the 

Finally there is DTS. DTS just has a time code dot pattern and serial 
number. From what I read, the decoder box uses CDs or DVDs that contain 
the audio. From what I have read the discs are just MS-DOS boot CDs that 
contain the executable that checks the serial number when it goes by and 
then chases the time code dot pattern with the however many channel 
digital sound. I guess these were used up until 2012.

I don't have any DTS stuff yet. Can't get the Dolby Digital stuff I have 
working yet.

Was surprised to hear it was MS-DOS and existed in the market that late.

 		- Ethan

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