[Coco] Reading/Writing Model I/III/4 Disks on a CoCo
Luis Antoniosi (CoCoDemus)
retrocanada76 at gmail.com
Thu Sep 5 17:32:52 EDT 2013
the seek was:
SEEK #out,(t*18 + s)*256.
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://five.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
>
--
Long live the CoCo
More information about the Coco
mailing list