[Coco] CoCo Model 1 Cartridge Port

[Charles Hudson]

Following your advice I moved the cable to the last connector (on the 
end with two connectors) and repeated the process of "dksini0".  This 
time the drive light came on and I could hear the stepper motor move the 
head.  I failed to count the steps - I was completely surprised - but a 
dozen steps or more activity ceased and the light went out.  The result 
on the screen once again stated IO ERROR.

I then tried repeating the disk format.  This time I heard the mechanism 
straining; no regular repeated stepping and after a few steps with long 
pauses between them the activity ceased and I got another IO ERROR message.

 From this I suspect that communication is good but maybe the drive 
mechanics or electronics are at fault.  It could be a tight sleeve, I 
guess, but I will eliminate that possibility after inspecting the drive 
mechanics.  I'll post back if I find something.

Thanks for your suggestions.

-CH-

On 12/24/2021 8:13 AM, Arthur Flexser wrote:
> 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-
>>>>
>>>>
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