On Thu, 29 Jan 1998 11:41:38 -0600 John Payson writes: >> Is anyone interested in backing up data to a standard videorecorder >> using a PC parallel port and a special designed interface with >PIC16c84 > >Such a concept would have been useful a few years ago. The idea is probably about a week newer than the personal computer and the VCR. Over the years, there have been several devices marketed to do this, but none very successful. Juno sent me something a few months ago advertising one. Nowadays, >however, >reasonably-priced tape drives can back up data faster and more >reliably >than a consumer-grade VCR. Especially with advances in recordable optical disks, the use of tape in general is no longer very viable. Even a primitive CDR disk, though it can only be recorded once, costs little and is much more reliable than any form of tape. While there may be some merit in the low >media >cost, VCR backup solutions are a pain in the tusch to use. If you >want to >make the thing work at all reasonably, you'll need to have a fair >amount >of RAM on your encoder/decoder board for buffering [e.g. 1MB] and have >it >incorporate enough intelligence to read/write large amounts of data >unatt- >ended. The seemingly high speed of VCR tape needs to be considered in light of by the poor quality of the media. An agressive error-control strategy involving interleaved Reed-Solomon recording as well as possibly even recording the same data twice at different places on the tape should be used. Even a very cheap backup system needs to be highly reliable. This can very quickly require a lot of RAM, though it may be possible to make the PC do all of the coding and buffering. A "dumb" interface may be the only way to go since it needs to be very inexpensive to have much appeal at all. It will likely never work except as a dedicated DOS application since if the processor is away for even a few ms all will be lost. So a lot of compatibility and user-interface problems arise. The Videobackup may be an interesting project, but don't expect to make any money with it. Many others have tried. > _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866]