Re: Lobo floppy drives
- Bill Degnan:
> >I agree. When you flip over the drives, check the PC boards for a PC board number. Then you'll know which set of schematics you'll need. They look like Shugart 800/801 to me but there will be more identification on them. I have organized my Shugart 800 docs based on PC board numbers:
> > Yup. Shugart 800 or 801s.
and there may be manuals specific to your drive versions on various PDF archive Web sites too. The 801 was simply an 800 with jumpers set to provide decoding of hard-sectored sector pulses. There's actually a 800/801 named jumper.
Lobo made products for TRS-80's and I think they had some kind of S-100 interface for another Z80 system in the era. But it doesn't matter: they simply wrapped a case around a manufacturer's drives. I imagine if you Google search their Infoworld magazine archive, you'll likely see some Lobo advertizing.
- On Sat, 15 Dec 2012, joshbensadon wrote:
> --- In email@example.com, Mike Loewen <mloewen@...> wrote:Here's the service manual for the Tandom TM-848, with the schematics in
>> The double-sided drives have a 2S signal on pin 10 of the interface
>> connector to indicate single or double-sided media. The outputs of the
>> respective pulse-shaping ciruitry for each sensor is essentially ORed to
>> form a single Index pulse output.
> Cool, so I can imagine the two sensor signals going to an RS flip flop
> to provide the 2S signal and as you said to an OR gate for the index.
Knock yourself out. :-)
> Hmm, thinking about why, I guess the design was to create a hardwareThe 5.25" drives only had a single index hole aperture.
> error if a user placed a DS disk into a SS drive. As Rich found, the
> lack of index pulses caused a drive not ready. Correct me if I'm wrong,
> but in later 5.25" drives, they did not change the index sensor
> location. Then I suppose the errors created would be software
> I vaguely remember hearing a discussion about how computers switchedI couldn't say. Certainly Woz did a lot in software for his Apple II
> from hardware solutions to software solutions, then back to hardware.
> I just don't know the dates, could this 8" to 5.25" be part of that
disk controller design. Another odd thing about the 8" drivers vs the
5-1/4" drives was that the 8" drives had a write-enable notch, while the
5-1/4: drives had a write-protect notch. Very confusing.
Mike Loewen mloewen@...
Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/