8" disk drive questions...

[Fred Cisin]

Put a piece of opaque tape over one of the holes.
Make sure that it is solidly attached.
I used to use write protect tabs.
But aged write protect tabs rarely still stick well.
And, it is a hassle to dig out ones that have fallen off inside the drive. 
I ran most of my 8" drives without cases, so it wasn't such a big deal.


Covering the index hole of the diskette was one crude work-around ("the 
band-aid") for reading certain WD formatted 5.25" disks using an NEC 
controller, where the NEC went "flash-blind" after the index, and then 
wasn't quite ready to read before the first sector of the WD disk (with 
short index gap) came around.  A better solution, for a non-temporary 
setup (for 5.25" index) was to make a special cable that interrupted that 
wire with a switch.


There are presumably jumpers on that drive, perhaps wire to those jumpers 
with an external switch?

Having both sets of holes on the disk lets the disk be formatted and used 
as either single sided or double sided.
Having both sets of sensors in the drive lets it be a single sided or 
double sided drive.

Neither were especially common, so the combination didn't happen often for 
most people.

--
Grumpy Ol' Fred     		cisin at xenosoft.com
XenoSoft                        http://www.xenosoft.com


On Sun, 31 Oct 2021, geneb via cctalk wrote:

>
> I'm working with the developer of the Applesauce disk imaging tool in order 
> to iron out some issues with 8" disk support.
>
> I'm using a Qumetrak 842 disk drive that's got support for both double and 
> single-sided media.  This means that it's equipped with two index hole 
> sensors, slightly offset from one another.  It's my understanding that 
> single-sided media has the index hole in one spot on the jacket, and 
> double-sided media has one in a slightly different location.
>
> The issue at hand is some NIB Dysan double-sided 8" media I have - the disks 
> have index holes in the jacket in both locations.  Is this typical, or do I 
> have some weird "special" disks on my hands?  The Applesauce author posits 
> that the combination of the dual-sensor drive and the dual-hole media 
> wouldn't typically find themselves together.  Is this accurate?  If it's not, 
> how would a system contemporary with the media have handled the two index 
> holes?
>
> Thanks!
>
> g.
>
> -- 
> Proud owner of F-15C 80-0007
> http://www.f15sim.com - The only one of its kind.
> http://www.diy-cockpits.org/coll - Go Collimated or Go Home.
> Some people collect things for a hobby.  Geeks collect hobbies.
>
> ScarletDME - The red hot Data Management Environment
> A Multi-Value database for the masses, not the classes.
> http://scarlet.deltasoft.com - Get it _today_!
>