I've seen that, as well. Would you believe dirty phototransistors? I have one of the drives working well. The other worked for a bit, then stopped recognizing the index again. I need to get back into it and do some tweaking. When checking the index sensor against the maintenance manual, I was able to adjust for a good pulse width (section 4.7.2) with the phototransistor pot on both drives. But, on the index/sector adjustment (4.7.3), I was unable to see the pulse as described. My scope was set up exactly as in 4.7.3, but I couldn't see it on either drive. I'll dive back into the troublesome drive, tomorrow. http://bitsavers.org/pdf/shugart/SA8xx/50575-4_SA800_Maint_Feb78.pdf On Tue, 22 Mar 2022, Jonathan Chapman wrote:
That's usually a sign you're getting no index pulse, in my experience.
Thanks, Jonathan
------- Original Message -------
On Tuesday, March 22nd, 2022 at 02:10, Mike Loewen via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
I have a pair of Shugart SA800-2 8" drives, which are mounted in a
Micromation enclosure. Both drives have the factory jumper configuration,
except for the B: drive which has the termination jumpers (T3, T4, T5 and T6)
removed and DS2 installed.
I've connected them to my media system via an older FDADAP board. Using the
IMD program, I try and read a single-sided disk that has valid data. The drive
selects and the head-load solenoid activates. After several seconds, IMD
displays a "No interrupt from FDC" error. The same thing happens with both
drives. The Alignment function doesn't recognize anything from the disk.
I've successfully used this system with Tandon TM848-2 drives, and a
Siemens 120-8. Before I start chasing signals, are there any obvious pitfalls
to using a SA800-2 with a (relatively) modern PC?
Should the DC (Disk Change) jumper be installed? By default, it is not. I
noticed that on the Tandon drive, DC is installed.
I have the operating and maintenance manuals for the SA800/801 drives.
Mike Loewen mloewen@cpumagic.scol.pa.us
Old Technology http://q7.neurotica.com/Oldtech/
Mike Loewen mloewen@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/