8" drive variations

[Jules Richardson]

Chuck Guzis wrote:
> On 13 Mar 2007 at 11:32, Jules Richardson wrote:
> 
>> As hinted at in another post a few days ago, I'd like to add an 8" drive (or 
>> possibly more than one if necessary) to my Imagedisk machine in order to be 
>> able to archive 8" media.
> ...
> 
> On many 8" drives, HS and SS operation is set by jumpers on the drive 
> electronics board. 

Generally-speaking I suppose I can just mess around with jumpers in the short 
term if there's anything I need to change between reads for different formats; 
maybe in the longer term there's a project to add parallel port control to 
ImageDisk and twiddle certain bits under software control, which can then be 
used to do various things :-)

(I assume by HS and SS you mean hard/soft sector? I always think of HS as 
"head select" and SS as "single step", but I can't imagine why you'd want to 
force-jumper either of those :-)

 > Some drives have an onboard FM data separator.

Indeed - I think I've come across that before. For drives that have it, can it 
typically be disabled?

> Seek rates and mechanisms can be all over the map.  Pinout need not 
> be the same (IIRC, Calcomp drives feed their power through the 44-pin 
> connector).  There is less of a standard form factor ((i.e. floppy 
> slots and latch positions are not usually the same from manufacturer 
> to manufacturer).  Power connectors can be significantly different.

Those are less of an issue I suppose; it's just cabling and mounting and power 
routing! I'm more worried about signal incompatibilities, I suppose.


> Forget about using a hard-sector drive with a 765-type controller.  
> It doesn't work that way.  Get a Catweasel if you want to do those.

Sure. I'm actually going to hunt out a decent Northstar Horizon when I'm back 
in the UK; I wonder how easy it would be to hook up an 8" drive to one of 
those (and whether anyone's already written any serial-port data transfer 
software to use one as a way of getting data off 8" disks onto modern media)?

cheers

Jules