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
