[Coco] Issues with 26-3022 interface

Daniel Campos daniel.campus at gmail.com
Tue Feb 12 22:10:40 EST 2013


Yes, at least RSDOS images are working like a charm. :-)

Still trying to make OS9 L1 images to work here. They start loading then 
hang...

Daniel

Em 13/02/2013 00:32, Juan Castro escreveu:
> I'm happy to inform Daniel used Jeff Vavasour's DSKINI MS-DOS program in an
> old PC and now he's transferring images like there's no tomorrow. I'm sure
> he can fill in more juicy details. Yo, Daniel! Manifest thyself!
>
> And now an idea I had. Could it be possible to program the CoCo FDC to
> format/read/write (a) additional tracks in the same side of the floppy, or
> (b) side 2 of the floppy, or (c) both?
>
> We could have four disks in one!
>
> I remember way back at the CoCo clone company I worked, we did a hack to
> interpret side two of the floppy as a second drive. IIRC, that involved
> some slight change in DECB to program the FDC differently if drive 1 or 3
> was being accessed.
>
> On Wed, Feb 13, 2013 at 12:12 AM, Juan Castro <jccyc1965 at gmail.com> wrote:
>
>> Your floppies have been formatted with 256 byte sectors. Each track has 18
>> sectors of 256 bytes instead of 9 sectors of 512 bytes like in a 720KB PC
>> disk. You'll need to (a) get a PC with a FDC old enough to read that, and
>> (b) get some DOS software that can program the FDC and read/write a 256
>> byte formatted disk. That will be a challenge. Anyone here has successfully
>> done that?
>>
>>
>> On Tue, Feb 12, 2013 at 1:26 PM, Daniel Campos <daniel.campus at gmail.com>wrote:
>>
>>> Hi Mark,
>>>
>>> I understand your point, as this subject have probably been talked on
>>> this list many times over. But my main purpose is to pass disk images from
>>> a PC (through emulator or some other program) and run them on the Coco. I
>>> don't have any legacy 5 1/4 disks to worry about, so if I can do this work
>>> on a 3 1/2 floppy, for me is the best choice.
>>>
>>> I will try now to transfer some images from the PC to this disks and
>>> let's see how will it work...
>>>
>>> Thanks!
>>> Daniel
>>>
>>> Em 12/02/2013 13:04, Mark Marlette escreveu:
>>>
>>>   Daniel,
>>>> Understand the beast in which you are trying to tame.......... :)
>>>>
>>>> Go read what occurs and the differences between all of the disk formats
>>>> and densities on a hardware and software level.
>>>>
>>>> You will then realize as it 'might' appear to have worked, you are in
>>>> violation of the specs.
>>>>
>>>> This has been beat to death here. Follow the specs and it will always
>>>> work.  You are flirting with diasater if you assume it is working, IMHO.
>>>>
>>>> Regards,
>>>>
>>>> Mark
>>>>
>>>> http://www.cloud9tech.com
>>>>
>>>>
>>>>
>>>> ______________________________**__
>>>>    From: Daniel Campos <daniel.campus at gmail.com>
>>>> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>>>> Sent: Tuesday, February 12, 2013 8:50 AM
>>>> Subject: Re: [Coco] Issues with 26-3022 interface
>>>>    Mark,
>>>>
>>>> Em 12/02/2013 11:56, Mark Marlette escreveu:
>>>>
>>>>> Daniel,
>>>>>
>>>>> This HD mod was created by Robert Brose of our computer club many years
>>>>> ago.
>>>>>
>>>>> I have done this mod, it works. I also added a line from the controller
>>>>> to the drive to automatically switch the transfer rate clock based upon the
>>>>> sensors in the drive rather than just the descriptor.
>>>>>
>>>>> With that said...this is NO easy mod. Almost easier making a new
>>>>> controller.
>>>>>
>>>> Yes, for what I saw from the document that Harry sent, it will be no
>>>> easy task.
>>>>
>>>>   It requires a the MB8877A(??) memory loss ATM upgrade and then there
>>>>> was also a speed issue running at 1.78MHZ as well. A chip that needed
>>>>> replacing. Was pinged this past weekend on this at Cloud-9 and haven't had
>>>>> the chance to look up my work in my project documentation book. I have it.
>>>>>
>>>>> The file was up on RTSI for a long time. ????
>>>>>
>>>>> Regards,
>>>>>
>>>>> Mark
>>>>> http://www.cloud9tech.com
>>>>>
>>>>>
>>>>>
>>>>>   Ou of curiosity, I just attached today a 3 1/2 1.44M drive to the Coco
>>>> and it worked flawlessly! It formated the disk (a HD disk with the role
>>>> closed to make the drive understand it as 720Kb disk) and SAVEd and
>>>> LOADed some programs. No errors ocurred during the format process!
>>>> How can I check the disk to see if it was formated properly ?
>>>>
>>>> This drive is a Mitsumi D359M3D and was already configured to DS0,
>>>> because I used it before with one of my MSX machines.
>>>>
>>>> Thanks!
>>>>
>>>> Daniel
>>>>




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