[Coco] Booting OS9 on my CoCo 3

[Gene Heskett]

On Tuesday 08 August 2017 03:36:17 Arthur Flexser wrote:

> Is it possible that you've configured OS-9 to expect a 40-track disk,
> but that the floppy drive you hooked up is physically not capable of
> 40-track operation? Some of the older RS drives could only handle
> something like 36 tracks.  The fast seeking could be the sound of the
> drive vainly trying to access an upper track.
>
> Art
>
Its a 3.5" drive art,so it has a 99.9999% percent chance of being a 
double sided, 80 tracks a side disk. 720k in other words or os9 since 
our controllers can't switch to a 500 kilobaud data rate from the coco's 
250 kilobaud rate without a rework of the original, needs 12 volts, 
controller. The WD1773 used in the later controllers can'r run that 
fast.

And it needs the softer magnetically "DD" diskettes to have good data 
retention.  At this late date, there simply is no way a taped over HD 
diskette will last this long. That would explain the re-seeking as its 
trying to read a track thats faded because it wasn't recorded at enough 
record head drive.

> On Tue, Aug 8, 2017 at 3:11 AM, Dave Philipsen <dave at davebiz.com> 
wrote:
> > Ok, so it's been a REAL long time since I booted OS9 on my real CoCo
> > 3 from a floppy disk.  Like almost thirty years.  So I picked up a
> > used FD501 controller from eBay awhile back and I just now hooked up
> > a 3.5" floppy to it.  I can format a floppy and I can save/load
> > programs from it.  But when I try to boot an old disk (probably 30
> > yrs old) I get the familiar "OS9 BOOT" screen and then the floppy
> > does a seek at what sounds like a faster step rate and then it does
> > nothing.  Frozen with "OS9 BOOT" on the screen and the floppy is
> > still selected with the motor running.
> >
> > This is a very old boot disk that I labeled "OS9 Level II System
> > Master with ramdisk".  My old setup was a CoCo 3 with 512K and a
> > multipak and one of the old full-size floppy controllers and an
> > RS232 Pak.  My new setup is a CoCo 3 with 128K, no MPI,  the FD501,
> > and a 63C09.
> >
> > I've got some 5.25" OS9 disks too but I don't currently have a 5.25"
> > drive so I'm hoping to get things worked out with the 3.5" drive. It
> > may be that the floppy is just so old it's lost some of its
> > retentivity but I just thought I'd put it out there to see if anyone
> > has an idea.  Maybe I'm missing something obvious.  The FD501 does
> > not seem to work at hi-speed. Could that be the problem?
> >
> > Dave
> >
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > https://pairlist5.pair.net/mailman/listinfo/coco


Cheers, Gene Heskett
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