Ted Green, now an official MAMEdev, did some more work on the IT Eagle driver. He’s kinda good…

Many of you probably saw this Tweet recently:

There are a lot of people on the MESS (not JSMESS) development group who are doing this work, and they're sweating over it, and I thank them

— Jason Scott (@textfiles) March 31, 2015

There’s one serious issue. MESS has a timing problem in our from-schematics reproduction of the Wozniak floppy controller. It conveniently manifests in a common regular .DSK (Sherwood Forest) but it’s also causing trouble for booting .EDDs which are more timing-sensitive than normal DOS 3.3 and ProDOS stuff. For instance, the protected original .EDD of Mark Turmell’s “Sneakers” loads all the way in but fails to read correct data for part of the boot because of this.

You can read a discussion of the issue on the MESS forum starting at this original report. Olivier Galibert, who wrote the floppy emulation, believes he counted all the cycles correctly and real hardware should reject Sherwood Forest. This is unfortunately rebuffed by real hardware, which boots the disk reliably. Apple II copy protection expert Peter Ferrie is also on the job and has been unable to figure anything out.

So this is where the call for help comes in: anyone out there who understands the Disk II controller well, we’d love to hear from you. The sooner this gets fixed, the sooner the awesome dream in Jason’s Tweets gets realized.

Contact methods: reply on the MESS forum linked above (if registering a new account, please follow the directions – the procedure is not identical to other forums!), submit a pull request on GitHub, or buzz me at messdrivers at gmail dot com.