ISO: Diablo 30 heads

[jim stephens]

On 5/11/2020 9:15 PM, Josh Dersch via cctalk wrote:
> Hi all --
>
> I'm restoring a Xerox Alto and I started going over the system's Diablo 30
> drive.  The heads are in bad shape; the bottom one is actually missing both
> parts of the erase poles (so the black portion of the head no longer makes
> a "t", it's just a black line).  This means the head (in addition to not
> being able to erase) also won't float due to the head having small cavities
> in them.  The upper head looks a little better but I'd love to find a set
> of upper and lower heads if anyone has spares.
This guy has had several of many of the types of heads you need. This is 
for a Microdata or Western Dynex of either the 2.5m / platter or 5m / 
platter variety.  Might bug him

MICRODATA-PN-20012187-3-NSN-1560-00-121-8703-DISK-HEAD-NEW-ORIG-BX-selectvintage/
https://www.ebay.com/itm/192169612454

Here's the list of stuff he has with all the heads.  There may be 
equivalents in there, don't know.

https://www.ebay.com/sch/Computers-Tablets-Networking/58058/m.html?item=192169612454&hash=item2cbe3394a6%3Ag%3AmvIAAOSwmCVZAP-S&_ssn=selectvintage&_sac=1

selectvintage is vendor.


>
> Then I get to learn how to align these things.
I've got one that would fit an RL02 and possibly an RL01, does work with 
Dynex or Microdata.

you might have to find an exerciser, and option the drive to the # of 
sectors.

You can get it playing with a recorded but expendable pack.  That is 
with a Microdata drive.  Maybe someone can also record some ones and 
zeros for the amp calibrations.  I don't know if they are doing the 
embedded servo thing or not, or the drive might choke on something.

I've gotten them going by setting up the basic drive function w/o 
alignment, so it can pass a formatting tests (again, not with embedded 
servo) on a blank pack.

Then you use the tester and the alignment and analog section with a data 
pack (not necessarily alignment) that has good data on it.  You can get 
by w/o an alignment pack that way.

thanks
jim
>
> Thanks!
> - Josh
>