Re: 3174 disks
| Newsgroups | gmane.comp.emulators.hercules390.general |
|---|---|
| Message-ID | <[email protected]> |
On 7/8/19 11:57 PM, Al Kossow [email protected] [hercules-390] wrote: >>> 1. What format are the 3174 disks? I know they're 2.4MB drives, but >>> are the floppies actually 2.4MB? >>> >> They probably have a non disclosed format, but the block sizes are >> probably pretty standard (512 Bytes/block). They are double sided 5.25 >> soft sectored HD (1.2MB per side). Cloning a diskette should be pretty >> easy. > > I was able to sort of read a 2.4MB disk in a 2.4MB drive with a flux-level > reader to determine they have twice the number of sectors/track as a 1.2MB > disk. > > Getting the IBM drive to switch into 2.4MB vertical record mode is the mystery. Knowing the technology of the day, it's probably done with a line on the interface. One possibly obvious way to make that determination is to look at the lines when a drive in a 3174 is accessing a 1.2MB disk, then a 2.4MB disk, and see what's different. -Dave -- Dave McGuire, AK4HZ New Kensington, PA ------------------------------------ ------------------------------------