Author: Steve (gate2-sandiego.nmci.navy.mil)
Date: 12-12-2005 17:24
The drive speed MOD for the 810 was a modification the gave the 810 Happy drive the ability to physically slow the actual speed of the drive motor WAAAAY down from the standard 288RPM all the way to @170RPM during an actual Happy backup of the EOA 34 Sector/track protection schemes.
Its ironic that the old Happy 810s could make a 1-1 copy of the 34 sector schemes.
During the copy the old Happy software would actual instruct you to remove the top cover of the 810 drive and turn down the RPM motor speed control. when it go to the right place, it would signal the user to stop! It would then write the 34 sector track correctly! the software then instructed the user to increase the speed back to 288 and the copy would then complete.
The auto-speed mod consisted of only a trim-pot and a few resistors. It added a second "lower gear" for the drive motor that Happy could toggle automatically if installed.
I don't believe that this ability was copied on the 1050 Happy, The Happy company caved-into pressure/threats from the industry. This is THE reason Happy HAD to create the PDB system! They MADE Happy alter the copy so that anything needing a PDB file would only run on a Happy drive.
Its ironic, that as far as making 1-1 working copies of the most heavily protected disk that would run on ANY drive the ultimate Happy rig was the 810 with auto speed mod and old v 5.6 software.
I used to have a pair of the the VERY rare 810 Happys that had the v7.x firmware update and COULD RUN run the v7.x software.
I should have kept them but traded them plus some other gear for a 1090XL expansion box...
Also you might be right about the Tamdon-MPI Power supply boards not being the same, the the daughter board is.
