Payton Byrd wrote:
<aiiadict@gmail.com> wrote in message 9be4b88f-8d42-4fc7-bd77-a2ca60c3a27b@d27g2000prf.googlegroups.com">news:9be4b88f-8d42-4fc7-bd77-a2ca60c3a27b@d27g2000prf.googlegroups.com...On Nov 20, 1:18 pm, Linards Ticmanis <ticma...@gmx.de> wrote:Michael J. Mahon wrote: > Does the C64 allow real-time fractional track stepping while reading? If you can fit it into the drive's own limited RAM, it should. The 1541drive is a basically a (user programmable) 6502-based computer of its own.In the last 10 years, many C64 guys have suggested the 1541 as a reader/writer/copier of MSDOS and copy protected disks for the AppleII... I have one in the attic. Maybe I'll try playing with it some day. RichI wasn't advocating using the 1541 (though I have in the past), but simply mentioning that raw GCR storage and interpretation on the PC has been done before. Given the more bare-metal control one has over the Disk-II I would suspect that someone here has the skill to design a USB device to control the Disk-II which streaming the raw GCR back to the PC over USB.
The problem is that on the Apple II, the reading process is directly controlled by data read from the disk in real time, meaning that the position and interpretation of the data depends on interpreting 6502 code in an RWTS that may be quite non-standard. This is hard to do without at least emulating a 6502. If you don't do this, then you have to guess at what magnetic transitions on the disk, at possibly fractional track positions, are meaningful, and in what way--a hard problem involving a *lot* of "data". -michael NadaPong: Network game demo for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."