[Coco] high density floppy controller mods

Mike Pepe lamune at doki-doki.net
Thu Aug 3 23:13:50 EDT 2006



Roger Merchberger wrote:

> 
> Well, if you're going to add that qualification, I doubt James was 
> referring to a magnetic-based optical drive! Altho they do exist - I 
> have an MO (magneto-optical) drive on my desk at work. AFAIK, the media 
> isn't magnetic, but it requires a strong magnetic field to change the 
> phase (i.e. write) the data to the media.
> 
> Also - if the optical medium was magnetic, it's quite possible that said 
> medium would be analog instead of digital; If I understand his 
> "definition" correctly, CD-RW's would be analog (phase changes on the 
> disk that refract the laser beam slightly) instead of digital (pits in 
> the medium which either reflect the laser or don't).
> 
> Paper tape is digital - either there's a hole, or there isn't. (I'm 
> *not* counting Floridian voting ballots!!! ;-)
> 
> That said - I guess you've never been around during the time of the 
> Texas Instruments TI-59 either, then....
> 
> "Good" Paper tape is actually Mylar - and there were small mylar "tape 
> strips" with magnetic medium on one side that was used for program 
> storage for the afore-mentioned programmable TI calc.
> 
> There - Magnetic Paper Tape. ;-)
> 
> Laterz,
> Roger "Merch" Merchberger
> 
> -- 
> Roger "Merch" Merchberger   | Anarchy doesn't scale well. -- Me
> zmerch at 30below.com.         |
> SysAdmin, Iceberg Computers
> 
> 

Yep, you're right about that. That reminds me of the old NJ Turnpike 
tickets which were IBM punch-cards but also had a magnetic strip on the 
back. The new ones still have the magnetic strip, although they are a 
lot smaller.

(However I'd bet the magnetic encoding is some analog signal)

-Mike



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