26 Jan
2014
26 Jan
'14
9:31 p.m.
Wow, I was just asking!
no need to bite my head off :)
I wonder about some of these "alignment" programs though.
You have to figure a few of them are just junk.
There was one that was only good for testing the speed of the drive,
you could adjust with a screwdriver. But that's all it did.
These things are becoming harder and harder to get ahold of.
The thread has been about the azimuth adjustment, getting head
replacements is now impossible.
1581 drives are next to impossible to find now.
How long before the current supply is gone?
Or how long before the caps on the boards go?
Eventually the c64 will be totally gone, left just to emulation.
DEC Vax systems are pretty close to the same state.
Amigas are starting to be hard to find.
I used to be able to take apart and replace chips in c64s,
you could read the code and understand it.
with only 38k of ram usable (aprox) it wasn't hard to understand the whole system.
nowadays, forget it.
Raspberry pi seems to have potential in this regard.
sorry for ranting, I just feel like great swaths of computing history is being lost.
And present technology has lost a certain special "magic" it used to have.
C64 was fun, a PC is a toaster, it's boring.
Dan.
Date: Sun, 26 Jan 2014 11:22:47 -0800
From: cisin at xenosoft.com
To: cctalk at classiccmp.org
Subject: RE: 1541 Alignment disk
I think I asked years ago about duplicating
these,
but is there a practical way to do that with just a 1541?
NO!
NO!
NO!
What you can get PRODUCED by a normal drive, is a NORMAL disk.
What you can get PRODUCED by a normal drive, is a NORMAL disk.
What you can get PRODUCED by a normal drive, is a NORMAL disk.
You CAN NOT produce an alignment disk using a normal drive with a normal
controller.
You CAN NOT produce an alignment disk using a normal drive with a normal
controller.
You CAN NOT produce an alignment disk using a normal drive with a normal
controller.
I mean, if you align a drive using a scope with
the disk,
then duplicate it, how reliable is that copy for alignment of other drives?
WORTHLESS.
What you create with the normal controller with normal drive is a NORMAL
disk. IT IS ABSOLUTELY NOT AN ALIGNMENT DISK!
A "digital alignment disk" is a disk produced using a special drive, that
DELIBERATELY has sectors written OUT OF ALIGNMENT, in order to see which
sectors (HOW FAR OUT OF ALIGNMENT, AND IN WHICH DIRECTION) can be read by
the drive. Doing so provides a "reasonable" level of measurement of how
far out of alignment the drive is, and which direction. A disk written
with a NORMAL drive is aligned for that drive, and can NOT check anything
except whether a given drive is close enbough to alignment with the drive
that created that disk to be able to reade it. People who think that
THAT is "correct alignment" really don't give a shit whether the drive is
accurately aligned, or where within the range that succeeds in reading
THAT disk it might be. It is "close enough" to be able to read/recover
disks written by that drive; it is NOT acceptable for writing disks,
particularly for distribution, or even exchanging with other people who
have been doing the same, and have drives ELSEWHERE in the range that
reads THEIR "known good" disk.
It is a BAD, STUPID IDEA!
If you take a yardstick, and use it to make marks on a stick, and then use
that stick to make marks on another stick, and continue to use each stick
to make the marks on the next stick, HOW MANY sticks can you make that you
would claim are accurate?
Disunirregardless of the alignment of the drive, ANY disks created by that
drive are aligned to that drive - they are ABSOLUTELY NOT a graduated
and calibrated series of misalignments - they are ALL aligned to that
drive. Yes, "piracy" programs (blow it out your ass if that offends you),
can make a "copy" of the disk. But THAT "copy" is aligned to that
drive,
it is NOT an alignment disk, and is absolutely totally useless for
checking alignment of anything.
An "analog" alignment disk can not be created with a "normal"
controller/drive combination. Instead of "normal" digital data/sectors,
it has SPECIAL tracks written by special hardware. They are analog tracks,
containing signals for testing drives, and a normal drive/controller can
read them, but can NOT write them.
So, anybody who claims to "duplicate" an alignment disk with stock
hardware, disunirregardless of what software is used, is an ignorant
asshole.