Vector 3/Teledisk

One approach to reading/writing hard sectored media would be to cook up a firmware set for, say, a UBICOM SX MCU that would be tasked to sample the signal coming from the drive and keep track of it with respect to the index/sector pulses, which, of course, could then be on the same line, since there'd be no FDC to get confused when they occur. The simple way would be to shuffle the sampled data into a RAM that's 9 bits wide, where the 9th bit would be the state of the index line. Software could beat on the resulting sample to format it into sensible and convenient form based on the vast oversampling done with the MCU. No hardware outside the MCU would be necessary, since the SX52, say, could mux the addresses to the 256Kb x 9 DRAM in firmware in plenty of time and would still have enough pins for the data and the disk I/O. The SX52 can drive an FDD cable without external buffers, by the way. All it would take is a bit of code and a 48 MHz oscillator. That happens to be a VERY convenient clock rate for this sort of task, too. Once a data massaging software set is whipped into line, the makers of TELEDISK couldn't complain about infringement, since there wouldn't be any, yet you could use the massaged data to rewrite the diskette image at a remote location once it was fiddled with enough to generate the appropriate write precomp, if needed. With an SX52 at a either 48 or 96 MHz, you could easily do this job, irrespective of whether the data is in manchester, GCR, FM, MFM, etc, since the analysis would be handled by the PC off-line. Meanwhile, the data just has to be transferred. These little MCU's cost about $8, IIRC. They're in a QFP with 0.65mm pin spacing but that's quite common. At least one British company, and several American ones, among others, make adapters to which they can be soldered and subsequently put in to a PGA socket. Moreover, if you don't mind drilling the holes, you can make such a thingie yourself. Dick ----- Original Message ----- From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com> To: <classiccmp(a)classiccmp.org> Sent: Sunday, September 09, 2001 7:28 PM Subject: Re: Vector 3/Teledisk