Odd floppy drives (was: Orbis

[Tony Duell]

> > to be non-successful. After all, the IBM PC caught on, as did VHS (in the 
> > latter case, the Philips V2000 system was better designed and better built).
> 
>   If you're talking about VHS and Beta, I suspect that VHS won because the

Not at all. V2000 is not Beta. It was a Philips-designed system that used 
flip-over tapes and recorder up to 4 hours each side.

What makes it interesting IMHO is that the heads are not fixed firmly to 
the drum, but are on piezo actuators, fed by slip rings and brush 
contacts on top of the drum. The heads follow the recorded tracks on the 
tape, there's fairly complex servo system for this, whcih means you can 
get noise-free slow motion, fast motion, and freeze-frame (on other VCR 
systems, the heads can't perfectly follow the tracks under these conditions).

The Philips machines (but not the Grundig ones) were very simple 
mechanically. They had 5 motors, with direct drive to the capstan, both 
spools, and the head drum. The fifth motor operated the loading mechanism 
to bring the tape round the drum. The only rubber part was the pinch 
roller, no belts, no idlers. Not even a back-tension band, back tension 
was provided by passing a small, controlled, current through the supply 
spool motor.

Electronically, the machine was full of plug-in boards. I can't remember 
all the funtions, but there was an IF strip, luminance, audio, 
chromanance, about 5 servo boards, system controm PSU, etc The system 
control was based on a mask-porgrammed 8048-series microcontroller. There 
was a diagnostic tool, which I'd love to find, that cosnsited ofa box 
containg an EPROM and address latch linked to a DIL clip. You clipped it 
onto the system cotnrol processor, it changed the state of the EA pin, 
causing said processor to execute the code in the diagnostic tool, not 
its internal ROM.

I have one of these machiens for UK PAL complete with the service manual, 
and a similar one for (French) SECAM. I am not sure there ever was an 
NTSC version.

-tony