On 01/15/2014 02:20 AM, Gene Heskett wrote: > > In a sense it was. Its Achilles heel was that everything in and out of it > had to go thru acca or accb, then moved to/from the register it was > to/from. A full machine cycle was several microseconds. But despite that, > it did manage to get my job done, which was run a tape machine with tight > timing control, backwards and forwards, doing audio and video inserts to > lay a new digitally generated academy leader on a commercial, and lay the > cue tones on audio channel 2 to make it work with a Microtime Automatic > Station Break machine. All dead on the money frame accurate. > > Oh, wow! Years ago, my company (Pico Systems) started out making a low-cost controller for animation, using editing VCRs. We supported several 3/4" U-Matic machines and industrial 1/2 VCRs, as well as the M-series machines that had separate heads for chrominance and luminance. Those SURE looked good!
First, you had to format the tape, which laid down a timing track on the audio channel. We had a circuit to generate an 18-bit time code with CRC. Then, when coming up to the insert point, it would read the time track until very close, then count off sync pulses to the exact insert frame, in case the frame of the insert had an audio dropout. This was pretty hard on the VCRs as they would sit with the heads spinning and tape tensioned for hours, while rocking back and forth through a couple seconds of tape repeatedly. I did it with a Z-80, a UART and a little additional circuitry for the time code processing. Overall control was via serial cable from the computer that was feeding the images to a frame buffer. When I started, Lyon Lamb was the only game in town, for $14000. Shortly after I got on the market, they lowered their price to $7K. I sold about 25 of them at $2K, but the magazine advertising was eating all the profit. The, VideoMedia came out with the VideoLan, little $600 boxes that communicated over 75 Ohm coax. One box connected to your computer, one to the VCR. So, for $1200, you could control one VCR. For an additonal $600,, you could control TWO VCRs! Well, that was so much more flexible, no way would anybody buy my gizmo, so I quickly pulled the ads. Jon ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
