Smartport Virtual Hard Drive
An external USB solution for the Apple II
3 History and News
8 Floppy Drives
9 Thanks !
8.Floppy drives familly
The floppy disk connector on the Apple 2 familly has evolved over time. Each new generation of floppy drive was compatible with the existing ones. We can distinguish three generations of devices:
- 1st generation - 5"1/2 floppy drive, the computer is commanding the drive directly at the electrical level
- 2nd generation - Intelligent 3"1/2 floppy drive, the drive has its own processor, and both the computer and the drive are exchanging messages. The dedicated processor of the drive was required as the data flow from the media was to high to be managed by the 1MHz processor of the Apple 2.
- 3th generation - Dumb 3"1/2 floppy drive, the computer has to be quicker and is commanding again the drive directly at the electrical level. With faster processor of the IIgs and the //c+, the computer was able to manage the data flow from 3"1/2 media, allowing to reduce the cost of the drives and achieve higher troughput than previous drives.
The SmartPortVHD device falls in the 2nd generation, like the Unidisk 3.5. This means the device has its own processor, so the computer doesn't manage motors and switches of the device. Instead, the computer sends a message and the dedicated processor inside the drive does all the required tasks itself to respond to the computer. In the SmartPortVHD device, a modern still 8 bits processor is replacing both the old 6502 and the dedicated controller (integrated woz machine). The dialog between the computer and the devices was greatly structured, and most of the possibilities were not used at the time, because of the higher cost and complexity of integrating a processor into a device. Today, the technology allows us to fully exploit this treasure.