[Coco] Regarding a cheap floppy emulator

[Juan Castro]

I tested the 720K one in a Dragon with a Lafumat controller. It kinda,
sorta works, but you can only read and write the first 256 bytes of
each sector of side 0 -- and there's only 9 of them in each track, so
no go. So close and yet so far.

With the 1.44 emulator (which I expected would work in similar
fashion, and it has 18 sectors per track) the Dragon can't even read
anything.

After that, I decided it was futile to test on a CoCo. Bummer.

Juan

On Mon, Sep 9, 2013 at 3:17 PM, Robert Hermanek
<rhermanek at centurytel.net> wrote:
> I played around with a China (affordable) emulator and verified, as
> expected, that although they work fine in a PC with 720 or 1440 images, they
> do not work in the coco.  The cheaper emulators are not configurable in any
> way, and always expect 80 tracks, 9 or 18 sectors per track, 512 byte
> sectors.  I was hoping against hope that with coco being 35 tracks, 18
> sectors, that the emulator would live with it, but I think the 256 vs 512
> byte sectors was a deal breaker.
>
> -RobertH
>
>
> On 9/9/2013 1:09 PM, Christopher Smith wrote:
>>
>> So, given that I may need to build my CoCo disk system from parts anyway,
>> I've been looking at the possibility of emulating one out of two floppy
>> drives in hardware.  There is at least one very impressive floppy emulator
>> available which will do everything I want, but it's upward of $100 and the
>> budget isn't so great for now.  I'm looking at the possibility using a
>> Chinese import emulator from ebay.  Supposedly it will emulate a 720k, 1.2M,
>> and 1.44M floppies.  Now, of these formats, I'm reasonably sure the CoCo
>> won't like any but the first.  That may be sufficient.  Here's what I'm
>> considering:
>>
>> I have a Teac 5.25" drive on order.  It's high-density, but people say
>> that these things have an RPM jumper on them which will slow the spindle
>> down.  You can then either force them to double-density mode or have them
>> function as quad-density.  People also say that the quad-density disks will
>> work out ok under OS-9.  I'd like to fit a switch onto the density selector
>> so that I can force the drive into either double or quad density mode at any
>> given time.  So that should make one good drive.
>>
>> I'm also thinking about trying one of those floppy emulators.  It would
>> need to be forced into 720k mode, and would basically work similarly to the
>> 5.25" disk in quad-density mode, I suspect.  The downside is that the
>> emulated disks would be smaller than usual under DECB, and unless I flipped
>> sides there either by attaching another switch that mucks around with the
>> side select signal on the cable or in software, I lose half of the space in
>> a disk image that I might have still had.  Though, OS-9 should use them at
>> full capacity, one would think.  My other problem here is that I strongly
>> suspect that this emulator will not have drive select jumpers, so I may need
>> to end up clipping pins, or -- who knows what, really -- to get the drives
>> in the order I'd like.  Really I think the emulated floppy should be drive 0
>> and the actual floppy 1.
>>
>> Any comments or suggestions on how to do this or why it's a bad idea and
>> something else should be done instead? :)
>>
>> All that aside, I'll still have the problem of housing the drives.  I've
>> recently salvaged an old case that had a CD-ROM in it, which should be
>> sufficient for a single drive, but I don't really have anything appropriate
>> for two drives.  A standard (and as small as possible) PC power supply of
>> even 60W or so should do fine for power, I think.  As for the box, I'm not
>> quite sure what to do there.  Perhaps wood I could do on my own.  Maybe I
>> could have something fabricated out of metal.  Something else?  Any ideas
>> here will be welcome as well.
>>
>>
>> Chris
>>
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco