Search found 120 matches
- Thu Jan 06, 2011 10:37 pm
- Forum: Support
- Topic: Track 0 disable signal on pin 33 - how to trigger?
- Replies: 8
- Views: 3216
Re: Track 0 disable signal on pin 33 - how to trigger?
Bummer. I just spent most of the day fixing this drive, and now it works as well as it's supposed to... but won't be useful for dumping. Well, thanks for the info. Just to bug you with YET ANOTHER question: Do you maybe know if there are any manufacturer whose drives tend to be able to do -8 after m...
- Thu Jan 06, 2011 10:00 pm
- Forum: Support
- Topic: Please explain what DTC does on giving up
- Replies: 5
- Views: 1652
Re: Please explain what DTC does on giving up
Yes, it's more clear now. Thanks a lot to both of you! I'll see what I can do with those old disks.
- Thu Jan 06, 2011 9:38 pm
- Forum: Support
- Topic: Track 0 disable signal on pin 33 - how to trigger?
- Replies: 8
- Views: 3216
Track 0 disable signal on pin 33 - how to trigger?
Mechanically my 5.25" drive (label says Newtronics D509V2..., motor is by Mitsumi) should be able to go a bit below track 0. I'd guess it does -4, probably I can make it reach -8 (slightly more than 2 mm below track 0, right?) with a bit of filing. Reading tracks 8 and above on the back side of...
- Thu Jan 06, 2011 12:07 pm
- Forum: Support
- Topic: Please explain what DTC does on giving up
- Replies: 5
- Views: 1652
Re: Please explain what DTC does on giving up
So do I get this right, even if only 1 sector of 18 was bad and 17 were perfectly readable, DTC writes that whole track in the sector image as empty, or not at all? If so, I'll wait for the documentation of the stream format. It looks like by and large, every byte encodes the length of one flux reve...
- Wed Jan 05, 2011 6:17 pm
- Forum: Support
- Topic: Please explain what DTC does on giving up
- Replies: 5
- Views: 1652
Please explain what DTC does on giving up
If DTC gives up on a track with errors in it after the maximum number of retries is reached - what is stored then in the (non-stream) image? The last read attempt? The single best read attempt? Or a collective "best of" that takes good (or nearly good) sectors from different reads and puts...
- Fri Dec 10, 2010 5:30 pm
- Forum: Support
- Topic: Negative track numbers
- Replies: 14
- Views: 3847
Re: Negative track numbers
Sure but what's the point? If a publisher did this, it wouldn't offer protection against anything more complicated than DISKCOPY.COM and the fact that you'd have to flip the disk would 1.) inconvenience the legitimate user and 2.) give away the trick to anybody even remotely tech savy.
- Mon Dec 06, 2010 9:56 pm
- Forum: Support
- Topic: Apple ][ disks
- Replies: 12
- Views: 7915
Re: Apple ][ disks
Even the Apple drives can usually read data fine if you're just a quarter-track away from the "right" position, thanks to the width of the head; valid data has to be at least one full track away from any other valid data to be readable. Thus, quarter tracks weren't useful for protection pu...
- Wed Dec 01, 2010 2:00 am
- Forum: Support
- Topic: Apple ][ disks
- Replies: 12
- Views: 7915
Re: Apple ][ disks
OK, I'm breaking my promise and continuing my rants... In the Apple controller the "MSB is always 1" rule is also used to delay the next bit-shifting by up to 3 cycles during reading, so that the fastest possible 6502 loop construct for checking whether a byte is complete (LDA abs,x + BPL,...
- Tue Nov 30, 2010 6:20 pm
- Forum: Support
- Topic: Apple ][ disks
- Replies: 12
- Views: 7915
Re: Apple ][ disks
Yeah, I was more or less answering to the post by mr.vince above, but without carefully reading it in the first place. Obviously you must understand the formats before they can be supported. And since the disk read routines in the Apple can in fact use much more RAM than in the Commodore drives whic...
- Tue Nov 30, 2010 6:20 am
- Forum: Support
- Topic: Apple ][ disks
- Replies: 12
- Views: 7915
Re: Apple ][ disks
Just FYI... Apple II drives are not intelligent at all, they use a low-level bitstream transfer from/to the host computer. The early and widespread "Disk ][" drive contains only four small ICs. There is one exception, the "Unidisk 3.5", which IS an intelligent drive containing a ...