[Coco] Reading/Writing Model I/III/4 Disks on a CoCo

Gene Heskett gheskett at wdtv.com
Thu Sep 5 17:44:03 EDT 2013


On Thursday 05 September 2013 17:42:33 Luis Antoniosi (CoCoDemus) did 
opine:

> the seek was:
> 
> SEEK #out,(t*18 + s)*256.

That on the face of it, should have worked, but that is not what you 
posted. :)

> On Thu, Sep 5, 2013 at 5:23 PM, Gene Heskett <gheskett at wdtv.com> wrote:
> > On Thursday 05 September 2013 16:41:08 Luis Antoniosi (CoCoDemus) did
> > 
> > opine:
> > > the default FLOPPY_DS80 from os9 build. Don't have it now. But I can
> > > format a disk:
> > > 
> > > format 2 '80' "DISK"r
> > > 
> > > without any problems. Why the BASIC09 can't seek further than 34 ?
> > > And about my backup.asm that had backup up correctly ? Seems to me
> > > there some check inside Basic09 functions.
> > 
> > Not that I am aware of.  I used the aftermerket ccdisk on a level 1
> > system in about '92 or so as I needed more capacity in my data disk
> > for my EDisk substitute.  So I booted from a 40 track ds disk but all
> > data was saved on an 80 track ds disk.
> > 
> > That whole thing was written in basic09, and talked serially to a
> > GVG-300-3A/B video production switcher, and while it didn't make heavy
> > use of seeks, it did open and read, or write the files sequentially
> > from head to tail.
> > 
> > The only 2 problems I had with it over about 15 years of continuous
> > service were disk controller related, and one op thought he had to
> > save any changes he might have made to his operating profiles bag of
> > tricks with a new filename every time he saved, eventually filling up
> > the data disk.  The disk controller problems stemmed from having a
> > 255 foot tall lightning attractor 30 feet out the back door, which
> > combined with none of that gear ever having the gleam in daddy's eye
> > to grow a properly static grounded line cord.  And those failures
> > were so rare it was hard to correlate them well enough to come up
> > with a sure answer.  So the best I did was to put a rack to case
> > ground wire on the drive boxes, after which I never lost another
> > controller.
> > 
> > > On Thu, Sep 5, 2013 at 3:15 PM, Gene Heskett <gheskett at wdtv.com> 
wrote:
> > > > On Thursday 05 September 2013 15:13:46 Luis Antoniosi (CoCoDemus)
> > > > did
> > > > 
> > > > opine:
> > > > > Gene I tried this:
> > > > > 
> > > > > OPEN #in,"image.dsk":READ
> > > > > OPEN #out,"/D0@":WRITE
> > > > > FOR t=34 TO 0 STEP -1
> > > > > FOR s=17 TO 0 STEP -1
> > > > > SEEK #in,(t*18)*256.
> > 
> > Here I think might be your error
> > 
> > > > > GET #in,sector
> > > > > SEEK #out,(t*18)*256.
> > 
> > ditto, neither of these seeks include s*256
> > S/B something that returns (t*4608 + s*256) where a track is 4608
> > bytes, and add s*256 to that for the final seek value.
> > And this one /will/ demand a properly preformatted diskette.
> > 
> > > > > PUT #out,sector
> > > > > NEXT s
> > > > > NEXT t
> > > > > CLOSE #in
> > > > > CLOSE #out
> > > > > 
> > > > > It gives me error when T is higher than 34!
> > 
> > And with a big enough buffer, say 4608 bytes defined as track, you
> > could read and write it by the track I expect, skipping all that
> > sector related hoohaw.  That might not be a lot faster because the
> > writes will still be subjected to looking for the next sector in the
> > interleave scheme, typically 3 for the coco's although I have used as
> > high as 8 when I was playing with bru.  8 gave me the best write
> > times, about 8 minutes an 84 track disk, but read/recovery was eons
> > slower at 32+ minutes a 756k disk.
> > 
> > BRU, to be an ultimately useful tool, needed a from scratch rewrite
> > with major architectural changes.  I never again found my round tuit
> > though. Which is why you never saw a BRU-2.0.  But the code is out
> > there, and somebody looking for a project with younger, less rusty
> > wet ram might want to take a look.  As it is, dsave, despite its
> > warts, is a better, faster way to do a backup.
> > 
> > > > Show us the output of "dmode /d0" please.
> > > > 
> > > > > Why does it copy backwards ? Because I want to write the LSN0 at
> > > > > last. Maybe the problem is the SEEK and not the GET/PUT. I
> > > > > didn't go further, I made an asm routine and solved my problem.
> > 
> > I believe it was in your seek calcs as you never read or wrote more
> > than the first sector of each track even if it didn't error out.
> > 
> > > > > On Thu, Sep 5, 2013 at 2:43 PM, Gene Heskett <gheskett at wdtv.com>
> > 
> > wrote:
> > > > > > On Thursday 05 September 2013 14:41:47 Luis Antoniosi
> > > > > > (CoCoDemus) did
> > > > > > 
> > > > > > opine:
> > > > > > > B09 won't support double sided.
> > > > > > 
> > > > > > Huh?  B09 only runs on os9.  And supports whatever the device
> > > > > > descriptor says.
> > > > > > 
> > > > > > > Also write to LSN0 at the end. Skip the first sector from
> > > > > > > both image and floppy, write all sectors and then reopen
> > > > > > > both image and floppy and then write to LSN0.
> > > > > > > 
> > > > > > > Don't use seek, just read and ignore as the seek seems to
> > > > > > > not work properly with non os-9 disks.
> > > > > > > 
> > > > > > > I have made a rawcopy tool for that, is at home I can send
> > > > > > > it you. it is in asm so it supports double sided disks as
> > > > > > > well. I made a dragon32 superdos disk using it.
> > > > > > > 
> > > > > > > On Thu, Sep 5, 2013 at 10:24 AM, Al Hartman
> > > > > > 
> > > > > > <alhartman6 at optonline.net>wrote:
> > > > > > > > Did it work? Have you successfully written an image?
> > > > > > > > 
> > > > > > > > - Al -
> > > > > > > > 
> > > > > > > > -----Original Message----- From: Gene Heskett
> > > > > > > > 
> > > > > > > > Sure there is, it took me about an hour to knock it out in
> > > > > > > > B09. Write LSN0, close the path, then reopen, and write
> > > > > > > > the whole thing one sector at a time.  The dbl write of
> > > > > > > > lsn0 is to get rid of the disk changed error.
> > > > > > > > 
> > > > > > > > --
> > > > > > > > Coco mailing list
> > > > > > > > Coco at maltedmedia.com
> > > > > > > > http://five.pairlist.net/**mailman/listinfo/coco<http://fi
> > > > > > > > ve.p airl ist. net/mailman/listinfo/coco>
> > > > > > 
> > > > > > Cheers, Gene
> > > > > > --
> > > > > > 
> > > > > > "There are four boxes to be used in defense of liberty:
> > > > > >  soap, ballot, jury, and ammo. Please use in that order."
> > > > > > 
> > > > > > -Ed Howdershelt (Author)
> > > > > > My web page: <http://gene.homelinux.net:6309/gene> should be
> > > > > > up!
> > > > > > 
> > > > > > I tried the clone syscall on me, but it didn't work.
> > > > > > 
> > > > > >                 -- Mike Neuffer trying to fix a serious time
> > > > > >                 problem
> > > > > > 
> > > > > > A pen in the hand of this president is far more
> > > > > > dangerous than 200 million guns in the hands of
> > > > > > 
> > > > > >          law-abiding citizens.
> > > > > > 
> > > > > > --
> > > > > > Coco mailing list
> > > > > > Coco at maltedmedia.com
> > > > > > http://five.pairlist.net/mailman/listinfo/coco
> > > > 
> > > > Cheers, Gene
> > > > --
> > > > 
> > > > "There are four boxes to be used in defense of liberty:
> > > >  soap, ballot, jury, and ammo. Please use in that order."
> > > > 
> > > > -Ed Howdershelt (Author)
> > > > My web page: <http://gene.homelinux.net:6309/gene> should be up!
> > > > 
> > > > "Once they go up, who cares where they come down?  That's not my
> > > > department."
> > > > 
> > > >                 -- Werner von Braun
> > > > 
> > > > A pen in the hand of this president is far more
> > > > dangerous than 200 million guns in the hands of
> > > > 
> > > >          law-abiding citizens.
> > > > 
> > > > --
> > > > Coco mailing list
> > > > Coco at maltedmedia.com
> > > > http://five.pairlist.net/mailman/listinfo/coco
> > 
> > Cheers, Gene
> > --
> > 
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > 
> > -Ed Howdershelt (Author)
> > My web page: <http://gene.homelinux.net:6309/gene> should be up!
> > 
> > Every living thing wants to survive.
> > 
> >                 -- Spock, "The Ultimate Computer", stardate 4731.3
> > 
> > A pen in the hand of this president is far more
> > dangerous than 200 million guns in the hands of
> > 
> >          law-abiding citizens.
> > 
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco


Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://gene.homelinux.net:6309/gene> should be up!

No guts, no glory.
A pen in the hand of this president is far more
dangerous than 200 million guns in the hands of
         law-abiding citizens.



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