[Coco] CoCo Model 1 Cartridge Port

[Arthur Flexser]

Sounds to me like the problem may well be with drive selection, that is,
the drive or cable is not properly configured to make the drive behave as
Drive 0.  It is normal for the drive motors of all drives to come on when
any drive is selected, but the red light not coming on seems like a tipoff
that drive selection is the problem.

Drive selection is accomplished in one of two ways.  If the cable is one
that originally came with the original (oldest) controller, model 26-3022,
it should have teeth pulled in the cable connector to accomplish drive
selection, by effectively disconnecting the select lines for the unwanted
drives.  Look at the end of the cable that plugs into the drive, head on,
and see if there are teeth that have been pulled.  Does the cable have
three connectors altogether, one at one end, which plugs into the
controller, and two more or less near the other end?  If so, try plugging
the drive into the opposite one that is near the other end, if you've got
pulled teeth in your cable.

The other way drive selection may be accomplished is by jumpers inside the
drive.  If your drive has a DS0 jumper, you want to turn on that one and
turn off any other jumpers that are designated DS1 or DS2.  There should
also be a removable terminating resistor inside the drive.
The terminating resistor should only be plugged in for the drive that is
last in line, that is, farthest from the CoCo.

Hope this helps!

Art

On Fri, Dec 24, 2021 at 6:40 AM Charles Hudson <charles484 at twc.com> wrote:

> Yesterday I connected the controller to the CoCo and to the TCDD,
> following the procedure illustrated in the Tandy CCDS documentation.  In
> specific, the ribbon cable's red stripe toward the rear of the machine,
> using the non-keyed end of the cable, and the keyed middle connector to
> the drive.  I issued the command "dskini0" to format a disk and the
> motor turned, but no red light showed on the drive and after a few
> seconds a message indicating an I/O error appeared on the screen.
>
> Looking at the error message list in the documentation three remedies
> are listed: make sure the disk is inserted properly, try another disk (I
> did both) , and call the Radio Shack Repair Center.  Not sure how to
> accomplish that one.  But I will take the drive apart and see if there
> is anything obviously wrong.  It occurs to me, however, that the fault
> may be with the controller or the cable.
>
> Does anyone have experience with this issue?  I'd appreciate some guidance.
>
> Thanks,
>
> -CH-
>
> On 12/23/2021 3:15 PM, Arthur Flexser wrote:
> > No, Disk Basic 1.1 resides exclusively in the Disk Controller's ROM.  You
> > must have Extended Basic to use any Disk Basic version, though.
> >
> > Art
> >
> > On Thu, Dec 23, 2021 at 8:40 AM Michael Miller <mvmiller12 at hotmail.com>
> > wrote:
> >
> >> I may be wrong here, but my understanding is that you need to update the
> >> ROMs in the actual computer to get DECB 1.1. The Disk Controller ROM
> just
> >> "expands" by adding a handful of commands.
> >>
> >> -----Original Message-----
> >> From: Coco <coco-bounces at maltedmedia.com> On Behalf Of Charles Hudson
> >> Sent: Thursday, December 23, 2021 7:12 AM
> >> To: coco at maltedmedia.com
> >> Subject: [Coco] CoCo Model 1 Cartridge Port
> >>
> >> On to the cartridge port, which seems workable.
> >>
> >> Verified that the Deluxe RS-232 Program Pak (Cat. 26-2226) can be
> invoked
> >> with "Exec &HC000"; I/O TBD.  Got modems and cables, need to find /
> create
> >> a driver.
> >>
> >> Also verified same for Disk Controller (Cat. 26-3022) which boots up
> with
> >> the message "Disk Extended Color Basic 1.0".  I have the disk cable, a
> >> drive and blank disks but no software.  End-to-end communication yet
> >> unproven.
> >>
> >> I think there are later ROM versions used with (some version of) the
> disk
> >> controller; can they be used in this cart?
> >>
> >> -CH-
> >>
> >>
> >> --
> >> Coco mailing list
> >> Coco at maltedmedia.com
> >> https://pairlist5.pair.net/mailman/listinfo/coco
> >>
> >> --
> >> Coco mailing list
> >> Coco at maltedmedia.com
> >> https://pairlist5.pair.net/mailman/listinfo/coco
> >>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco
>