Reading FM single density encoding on Apple II disk controller

[Oldcoder]

I read that there was an early version of the P6 statemachine PROM for FM encoding.

Is anyone aware of the PROM contents and the driver software to implement a standard 80k FM 1SSD drive support?

Issues are: 1) P6' Statemachine PROM,
2) Changing the P5 driver code to step 40T and not just 35.

Any OS changes to support 80k vers 140K GCR disks.

This could be to modify an 2nd disk controller card.


Peter

 

[Chuck(G)]

Have you consulted Jim Sather's "Understanding the Apple IIe" book? He lays out in exquisite detail, the contents of the PROM and how it works. It was good enough for me to design an Apple II disk controller for the IBM PC back then.

 

[Oldcoder]

Have you consulted Jim Sather's "Understanding the Apple IIe" book? He lays out in exquisite detail, the contents of the PROM and how it works. It was good enough for me to design an Apple II disk controller for the IBM PC back then.[/QUOTE

Chuck is that significantly different to chapter 9 in his 'Understanding the Apple II' book? I have looked at the Apple ][ version as I have a ][ Europlus but not the IIe version.

Peter

 

[Chuck(G)]

I'm not sure--does the II book contain information on RWTS 3.3 encoding?