DOS 2.0D bug: Duplicate Disk reads first three sectors with 256 byte DBYT

[+bob1200xl]

41 minutes ago, tschak909 said:

i'd call that a bug.

-Thom

 

Ya Think??

 

Not a feature?

 

Bob

[tschak909]

4 minutes ago, bob1200xl said:

Ya Think??

 

Not a feature?

 

Bob

Kopee Prowtektiun!

-Thom

[Kyle22]

So it looks like there is still no easy way to copy Indus CP/M disks...?

(1-3 are 256).

 

[+bob1200xl]

815 and Density Switch...

 

Bob

DOS20D.atr dos4815.atr

[tschak909]

OKAY.

 

so, DOS20D is configured for one drive.

 

also the sector count sizes are 4 digits, but after a poke and a write, and a reboot, it does do the right thing with duplicate.

 

dos4815 also works with duplicate.

 

Interestingly enough, the DOS menu is uppercase, like it is in the 815 manual. The other versions of 2.0D floating about are mixed case, and have this duplicate bug (one copy that I have, another I got on AtariMania), so, okay.

 

Weird but at least it's not an implementation snafu on my end.  Thank goodness.

 

I have plenty of OTHER implementation bugs to squish

 

THANKS, BOB!

 

-Thom

[_The Doctor__]

guess that why it sounded like something was still not right. bad disk or someones hack?

 

as for the poking/write/reboot...  that's the way you added additional drives in the good old days...

Edited March 27, 2020 by _The Doctor__

[+bob1200xl]

Yes, actually, DOS20D sets the number of drives at boot, if I remember it right. You can have up to 4 drives configured auto-magically. I don't think LOMEM is off, either.

 

Bob

 

[+Nezgar]

Interesting about the lower/uppercase. I was wondering about that in the back of my mind too, it seemed out of place from Atari. It's all clear now if the original disk was uppercase, all pointing to someone's hacks.

 

Thanks @bob1200xl for the authentic dump!

[tschak909]

so which file is the official Master Diskette CX8201?

 

-Thom

[+bob1200xl]

DOS4815 is the 815 Master Diskette.

 

Maybe we can get Kevin to verify that?

 

Bob

 

[tschak909]

The Amdek patched DOS relies wholly on the double density "Status" bit.

-Thom

[stuarts]

Yes I had a percom double density drive, and they did supply a patch disk that converted atari dos to dos 2.0D and I think it only worked in double density.  I'm guessing now that there may be different versions of this dos around, one for the 815 and the percom one.  I can't remember if there was a utility to switch density, but there may have been.  I was having problems using the sdrive max with a version I downloaded not formatting the new virtual disks correctly and this may be the reason.   The percom patched version should work correctly.  The first 3 sectors were 128 bytes per sector to maintain compatiblity with the bootstrap code in the atari os, the rest of the sectors were 256 bytes per sector.  If I remember right there were 3 bytes at the end of each sector that indicated which sector was the next sector in the chain of sectors to be read, or something like that.  I now understand that it may have been dos 2.0P for percom, but I remember it as a 2.0D for some reason.

 

Edited April 19, 2020 by stuarts

[_The Doctor__]

Looks like today is the day for version conflicts.... we're on a roll... and this one is a DOS one too :)

 

[luckybuck]

Last year, the worldwide Atari community had finished: https://atariwiki.org/wiki/Wiki.jsp?page=The Atari Accountant Series

In there, we have a description for the 815:https://atariwiki.org/wiki/Wiki.jsp?page=Read%2C write or convert from an Atari 815 Double Disk Drive

Maybe, this is of help?

@Bob, Kevin and Curt: Yes, a Kryo-or SCP-image of the original 815 Master disk CX8201 and a maybe CX8202 if in any kind pre-formatted like in the 2nd attached picture(?) would be of great help for the community! The pre-formatted disks from Atari boot faster, if no new format disk is choosen. Pre-formatted example for 810 only, please see the last picture. Thanks to the the members of the preservation project, row 2 in 1st picture is already done. Just the 3rd, last row is missing. Therefore, Bob or Curt, you can help us a lot. Thank you in the name of the community.

[_The Doctor__]

They are preformatted single density disks with appropriate notches / holes utilizing the fast sector layout from factory that are single sided up until the last one that is double density certified and laid out in 815 mode.

later 810's formatted in the better layout of sectors as well.

Edited April 28, 2020 by _The Doctor__

[luckybuck]

Thank you Doctor, already late here, so, there is one 815 pre-formatted disk from Atari missing in the table of the 1st picture?

 

[_The Doctor__]

nope, your chart appears correct and shows that which Atari provided.

 

remember the blank disk that was certified double density could be formatted single by the 810 or double by the 815.

 

to be honest, we formatted plenty of certified single disks as double just fine and nibble notched them using the second side on 1050's etc

Edited April 28, 2020 by _The Doctor__

[luckybuck]

Ah o. k., so no pre-formatted emty speed up booting disk for the 815...

But wait, if the info above is correct, then we just have to take a 815 master disk, CX8201, delete DOS.SYS and DUP.SYS and have an empty 'turbo' booting disk for the 815. ?

My suggestion: CX8203

[+Nezgar]

The Fast/Slow formatted disks was only a thing for the 810's... The pre-formatted disks were a courtesy to poor souls with Rev B ROM 810's (80-late 81). Those with rev C ROM 810's (late 81 and onward, or upgraded) and pretty much every drive that followed would format the faster sector interleave.

 

I'm sure the 815 only had one interleave used, it would have to be totally different from 810 due to double density sectors taking twice as long to transmit over SIO. No need for Atari to provide pre-formatted disks because they would provide no performance benefit... I also highly doubt the sector interleave on Atari's pre-formatted disks are aligned with timing holes... But maybe a flux level image could confirm? That could be interesting as that would suggest wheter Atari formatted them using 810's (Would not be aligned since they don't use the timing hole) or some other duplication platform (could be aligned)

 

@luckybuck there was a previous topic about the CX8100, where I am positive that this disk would be truly blank, never formatted, intended to be formatted by the user. A flux level image should show only random noise throughout the entire surface.

[luckybuck]

Thanks Nezgar, yes, we have a Kryoflux image of the CX8111, but we haven't investigated it yet. CX8104 as well.

But CX8100 and CX8202 are blank and therefore without any formatting, I assume. Honestly, to my mind, just the sticker is different on these 2 kind of disks...

I can send you the kryo image of a CX8111, if you want? These things, you know from the Accountant, are above my level for now.

So, then just a CX8201 kryo image and the empty disk project is finished. ? Sorry, yes, I am totally old-fashioned with the 800 and OS B PAL(!)created from the source code.

Didn't knew, that from XL and XE on this was fixed. Thank you very much for the update, highly appreciated.

[+Nezgar]

38 minutes ago, luckybuck said:

I can send you the kryo image of a CX8111, if you want?

Yes, I'm curious now, i'll PM you.

38 minutes ago, luckybuck said:

Didn't knew, that from XL and XE on this was fixed.

To what are you referring to? If you mean the "fast" or "slow" single density interleave, that was determined by the ROM in the 810 drive when formatting disks (Rev B=Slow, Rev C=Fast), not by the computer's OS.

[luckybuck]

PM is not necessary, have your data. Will upload and send you the link.

 

Another point, update here:

https://atariwiki.org/wiki/Wiki.jsp?page=Articles#section-Articles-SourceCode

for the B and C version is needed....

 

Thank you.