[Coco] Advice on copying old floppies

Carey Eugene carey at cebridge.net
Thu Jun 29 23:18:00 EDT 2006


Robert;

> WinXP or other NT system will not permit direct access of hardware. 
> That's why most of the programs written to read Coco or OS-9 disks fail. 
> It is not the format but the inability to talk directly to the floppy drive.

It's true that XP wont let programs talk to the hardware.

But you don't need direct hardware access to read CoCo disks.

You can do it with DOS / BIOS calls.  No actual talking to the hardware.

I'd have to go hunt up the old OS9 source code, but if I remember right from way back then, it was done just by filling in a few fields and doing officially documented BIOS calls.

Also I remember a few other 'read dos' programs that used a similar method.

Apparently XP doesn't pay attention to the proper fields in the INT bios call.  Even in the DOS box.  (Hmmm.... I wonder.  I used 'cmd', which is the new XP dos box.  I wonder if it would work in the old command.com dos box?  I can't test that right now cause that computer is busy, but I may give it a try later.)

Oh so long ago I was interested in the floppy format and got the spec sheets for the coco floppy controller, and even wrote a nice 'format floppy' program and messed with some pc floppy stuff, etc.  Been a looong time, though.

The PC floppy controller is fairly versatile, but it does have limitations compared to what the CoCo uses.  One of which is that it doesn't reset fast enough to always be able to read data after the index hole.  The coco & os9 format puts it a little too soon for what the PC likes.  (Well, the old floppy controllers used to be like that.  Not much telling what today's floppy controllers are like.  I haven't checked in a long time.)



>> Booting to DOS would be difficult....
>> 
>> The hard drive is NTFS, so I wouldn't be able to save the image.  I would rather avoid backing up the disk, reformating it and installing DOS or Win98 to do this.  I could it, but I'd rather avoid it...
>> 
>  Should not be a problem. WinXP will create a bootable floppy that 
> stops at DOS. Since the WinXP floppies hold more data than most Coco 
> floppies, you could read the Coco disk to a RAM disk, and save the image 
> back to a blank PC floppy.

Well, it's more difficult than that.

The system I put the 5.25" drive in can only handle a single floppy.  That's all the BIOS will recognize.

So I can have either a 3.5" or a 5.25", but not both.  I was surprised because I had just hooked up both.

But even if I could have both, transfering disk images like that would be rather tedious.  Better than nothing, but not fun.

(My main system can have two floppies, but I only two 5.25" drive bays.  One has a dvd burner and the other has a hard drive cooler.  I don't really want to remove the dvd drive because I use it.  And I'm certainly not removing the hard drive cooler fan.)

>> I'm giving the OmniFlop a try.  It needs a reg code to work on CoCo disks, and the program isn't wanting to activate with the code that was sent to me.  I've got an email out to the author, so hopefully I will hear something soon.
>> 
> It took me about a week to get a registration code. However, the author 

I used the web form.  Filled it out and got it via email within 60 seconds.


> once contacted is very responsive and will help you with any problems 
> regarding OmniFlop. Or you could post any problems here and those of us 
> that have used the program might be able to provide help.

The program isn't accepting the registration code that was mailed to me.  It's not rejecting it, but it looks like the program is just ignoring it because it still tells me that I have to register before I can use it.

I've emailed him about it.  There might be a problem of some sort on his web based key generator, or maybe a bug in the program itself.


Carey
 




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