After buying a replacement Apple //e earlier this year, I wanted to find and Apple Disk II Controller Card and at least one Disk II 5.25″ floppy drive.
It took me a while to find a reasonably priced used Apple Disk II controller card and Disk II floppy drive on eBay. The card and drive needed a good cleaning before I tried to use them. While there was dust in the floppy drive, the read/write head was still remarkably clean. The card had a bent pin 1 on the drive 1 connector. I carefully bent it back into position. I used 70% Isopropyl Alcohol to clean the card and some DeoxIT D5 in the Apple //e’s expansion slot to ensure a good contact between the card and the computer.
One thing that I did learn was that I was unable to have both a Disk II controller card and the newer Apple I/O controller card, for use with the Apple DuoDrive, in the same machine. To get my Apple //e to boot from the Disk II controller card, I had to remove the Apple I/O controller card before the computer would boot properly. While you apparently can’t mix and match these two types of 5.25″ Apple controller cards, you can have two Disk II or two Apple I/O controller cards installed at the same time. Just not one of each. In my experience using the //e back in the mid-1980s, you either had two Disk II drives or a single DuoDisk drive. You never mixed the two systems.
Disk II History
The Disk II system for the Apple II, II+ and the //e offered users improved data transfer rates over cassette tape-based storage systems and allowed for the direct access of a file by name, according to the 1982 version of the Disk II Installation manual.
According to the Disk II article posted on Apple2History.og, Apple CEO Mike Markkula wanted a faster way to load programs on his Apple II. Steve Wozniak set out on the task of creating a custom disk drive controller board. Steve Jobs brokered a deal with Shugart Associates to sell Apple stripped down versions of the SA-400 disk mechanism.
The Disk II Floppy Disk System, consisting of a Disk II controller card and a Disk II floppy drive, was made available for pre-order at a cost of $495 in June of 1978. Once Apple started shipping the Disk II, the price increased to $595.
A single Disk II controller card was able to drive up to two floppy drives. The drives received power from the controller card which is plugged into an expansion slot on an Apple II-series motherboard.
Early versions of the Disk II system were able to store up to 113.75 KB when using Apple DOS 3.2.1 and earlier. With Apple DOS 3.3, the version of DOS that I use with my Apple //e computers, Disk II was able to write 140 KB disks. Apple provided a 13 to 16-sector conversion utility to upgrade disks for use with newer versions of Apple DOS.