I wonder if Kryoflux or Greaseweasle can accurately replicate Datalife Disk Drive Analyzer media?
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Alignment disks (analog or digital) cannot be written by any commercially available drives, regardless of the controller used.
cannot be written, but can it be read in entirety?
Why would you want to? Reading isn't really a thing with alignment disks there is literally no data to "read". Sure you can spin the disk and read the bits, but why?
Disk drives are really digital devices in that they read/write one of two possible states representing either a 0 or 1.
The alignment disks, as mentioned earlier, are different. These are created using an ANALOG signal. This is kinda like all the "space" between 0:1 in the digital domain. While we can get into deep discussion over symantecs regarding what the difference is, let's just understand they are different.
AFAIK at the current time there is no way to duplicate. But... there's also like zero demand too! The Disk II drives are tanks and unless you do something to require an calibration/alignment you really shouldn't ever need one! You really should understand... these disks are something 99.9999% of the people using Apple II computers today will have no use for. The number of folks that know how to use the disks is low, and there' s also the need for additional test hardware . Even though the world's population has increased significantly since the 80's you'll find there are far less people today that actually know how to use these disks and can use them effectively.
There were both digital and analog alignment disks, which were written with subtly different patterns and designed to be used in different ways. Analog alignment disks (AADs) have non-concentric tracks that make a characteristic "cat's eye" pattern when the head amplifier is probed using an oscilloscope. The track is actually not circular but elliptical, so there is no way that it can be written on any normal drive even if it was modified in some way. Digital alignment disks (DADs) have circular tracks, but they are spaced in a way that must be extremely precise, which—again—no normal drive can accomplish without some serious modifications.
"Capturing" the pattern of data is useless, because it has no meaning without the physical disk media in the physical drive, hooked up to the physical oscilloscope. Unlike a normal diskette where the data should be the same when read on different drives, the entire point of an alignment disk is that the data read is different when the drive is adjusted in the slightest way—that's how you know the drive is aligned!
The Datalife Disk Drive Analyzer wasn't very good.
And it's alignment "test" consisted of whether or not it could read a passage on the diskette.
It told you that the drive was "aligned" or "not aligned". It didn't have any method of guiding the user on how to align a disk drive, and probably for a good reason - because a little knowledge is dangerous, and most people would completely EFF up their drive monkeying around with it.
It also was NOT an alignment diskette - it disn't have flux data on it that could be read by an oscilloscope to find the right head alignment.
There is only one consumer method that could help align a disk drive and do it in a fairly effective manner with reasonable precision, and that was the Call A.P.P.L.E. title called APTEST. It had a reasonable method of actually performing an alignment with decent repeatability.
It required a few known-good diskettes, preferrably commercially produced diskettes that had a good chance of being written by machinery that was properly aligned to begin with and it used "going-to" and "coming-from" tracks and half-track movements to determine whether the data was being read properly. A very good tool that yielded good results.
The Datalife Disk Drive Analyzer was just a toy in comparison.
p.s. There was one other field-alignment method that I used to use to do coarse alignments on drives that people screwed up.
I'd write a small BASIC program that looked something like this:
10 ONERR GOTO 20
20 PRINT CHR$(4)"CATALOG,D2"
30 GOTO 20
And then stick a DOS 3.3 formatted (from a known-good disk drive which was D1) diskette in the suspect drive (D2) and run the program.
The drive would grind and grind on track 0 not able to find the catalog. I'd then loosen the stepper motor mounts and rotate the stepper motor back and forth a little at a time until the drive read the catalog properly. It was crude but it worked.