External 1.2MB 8″ floppy disk drive
Abstract:
I have a weird obsession with ancient storage media, so I bought a 8″ floppy disk drive built in 1983 and a pack of disks. I wanted the ability to read and write these ridiculous floppies but I wasn’t interested in buying a huge IBM Displaywriter to go with it.
This project is a low-level controller for the IBM 6360 with a USB interface.
Signal | Comments |
Data Bus Bit [0-7] | Typical 8-bit data bus. |
Address Bit [1-4, 8] | Each disk has 77 tracks. Each track has 26 sectors of 128 bytes each. 5 address bits can locate 32 indices – perhaps these are registers in the onboard disk controller? |
DMA [Request, Acknowledge, Request transmit, Request receive, Acknowledge transmit, Acknowledge receive] | Perhaps there are 3 stages: 1. A DMA write (transmit) or read (receive) is requested by the host. 2. The DMA action is acknowledged by the disk controller. 3. A data block is contiguously sent from either the host or the drive. 4. The DMA request line is deasserted. |
Interrupt [1, 4, 7] | WTF |
Diskette Select | |
Diskette Ready | |
I/O Read | |
I/O Write | |
Terminal Count | |
Select | Side select? |
Reset | Obvi. |
Resources:
- https://hackaday.com/2017/01/22/an-eight-inch-floppy-for-your-retrocomputer/
- http://www.smbaker.com/qume-842-8-floppy-drive-with-a-rc2014-z80-retrocomputer
- http://bitsavers.trailing-edge.com/pdf/ibm/6580_Displaywriter/
- https://www.youtube.com/watch?v=mlRQAzzwzPA
- https://www.digikey.com/short/pqrdcj
- https://github.com/roybaer/usb_floppy_adapter
- https://hackaday.com/tag/floppy/
- http://hxc2001.free.fr/floppy_drive_emulator/
- https://www.digikey.com/products/en/connectors-interconnects/d-sub-connectors/439?k=DB37&k=&pkeyword=DB37&sv=0&pv589=25&sf=1&FV=ffe001b7%2C1140050&quantity=&ColumnSort=1000011&page=1&stock=1&pageSize=25
Did you ever figure it out? I have the same fascination as you!