Vintage Apple IIe A9M0104 5.25" Unidisk Floppy Drive Pair Drive 1 and 2 - $138 - (Springfield, MO)
This listing is for a Vintage Apple IIe Peripherals Unidesk 5.25" Model No. A9M0104. This item is a personal item that belongs to the shop owner. It worked last time it was used several years ago. This unit is yellowing with age, it does come with the original cables, we do not have the original box this unit came in. You will receive both drives, 1 and 2 that came with the original Apple IIe System. If you have any question please feel free to let us know. Below is some supplemental information from Wikipedia.Apple did not originally offer a disk drive for the Apple II, which used data cassette storage like other microcomputers of the time. Apple executive Mike Markkula asked cofounder Steve Wozniak to design a drive system for the computer after finding that a checkbook-balancing program Markkula had written took too long to load from tape.[1] Wozniak knew nothing about disk controllers, but while at Hewlett-Packard had designed a simple, five-chip circuit to operate a Shugart Associates drive. Wozniak began studying existing floppy controllers, including North Star and IBM models. Standard floppy controller boards were large devices that used dozens of TTL chips. In addition to being expensive, they were also much too big to fit into the Apple II's small case. Initially, Wozniak attempted to develop an FM-type controller with a smaller chip count and by making improvements to the FM encoding scheme, he was able to squeeze out 10 sector per track storage. However, he soon decided he could do even better and switched to another, completely different "5 and 3 encoding" method known as "GCR" (Group Coded Recording) which was a modified version of recording schemes used on tape storage. This allowed still more storage, up to 13 sectors per track. Wozniak called the resultant Disk II system "my most incredible experience at Apple and the finest job I did", and credited it and VisiCalc with the Apple II's success.[2]Along with the UniDisk 3.5", Apple introduced the U…
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From ebay.com - 1 month ago