[Coco] Playing games from floppies

Andrew keeper63 at cox.net
Tue Dec 19 22:57:14 EST 2017


Back in the day (well, I still have it actually) with my CoCo 2 and 3 as 
a kid, I had more than a few floppies with cartridge games on them. If 
you look thru back issues of the Rainbow, Hot CoCo and the like, you 
should be able to find the technique on how to transfer them. IIRC, you 
need to have an MPI or a Y-adapter for the cartridge slot so you can 
have both the floppy controller and the cartridge plugged in at the same 

There was a pin on the end of the cartridge that you had to cover with a 
piece of tape (IIRC, it was some kind of interrupt pin). This would 
allow the CoCo to boot up with the floppy controller, and not boot the 
cartridge, but by virtue of being on the bus, it was still mapped into 
memory, I think. You could then easily save the binary image from memory 
to the floppy.

This was only valid though for the simpler cartridges that didn't use 
any fancy address/mapping hardware for more memory space (I think games 
like Thexder, Pitfall, RoboCop, etc - used this scheme; I recall an 
article about it in the Rainbow as well, from probably 1987-90 or so); 
basically almost all of the old-school 4 and 8k cartridges could be 
transferred like this - and they floated all over the BBS network back 
then, too.

As such, there really isn't a need to worry about going at it alone, 
yourself, unless you have something that isn't in the archives already 
(and if you do, we would love to hear about it - likely more than a few 
of us would help with preservation if needed).

But if you browse the archives, you can generally find cartridge dumps - 
most end in .BIN or such; I don't recall the exact process for loading 
them from a floppy (LOADM "GAMENAME.BIN" - probably needs an offset, 
maybe a CLEAR or EXEC at some address?) - but again, scour the Rainbow 
and such for info - it's out there.

So - how to get them to your CoCo floppy drive? That's - a bit more 
complicated. As others have said, DriveWire is probably the easiest and 
best way today, but if you didn't want to go that route...

...build a PC. Basically, you want to make a "retro" DOS PC with a 5.25 
floppy drive; you'll want (ideally) a DSDD drive, and you'll need a 
motherboard or floppy controller to plug it into; an old Pentium box 
would be perfect. Install DOS (a copy of 6.22 would be best - FreeDOS 
might also work, or Caldera OpenDOS if you're feeling adventurous), then 
set up one of the DOS emulators (I am partial to Jeff Vavasour's work, 
personally), plus all of the DOS tools.

Format a floppy on the CoCo, then pop it in on the PC and start up the 
emulator; make sure you can mount and read/write to the physical floppy 
drive on the PC, and that you can read what you wrote on the CoCo. Get 
that working - it isn't difficult.

Also on the PC - install a DOS supported ethernet card (an old Intel or 
3COM EISA card is perfect if you can find one), then search around for 
the various ethernet DOS tools out there; there's one out there that's 
an FTP server that you can setup, then use an FTP client on your main PC 
(or Mac or whatnot) to transfer files to the DOS machine. From there, 
you can then stop the server (you can only do one thing at a time under 
DOS), then use the CoCo/DOS floppy tools to transfer the file to your 
RSDOS formatted floppy, and test it out on the emulator. If it works 
there, then try it on the actual machine.

Otherwise, you might also set up a 3.5" floppy drive on the same 
machine, and transfer from the internet PC to the DOS PC via 3.5" 
floppies (you may need to find a USB 3.5" floppy drive for your modern 
box, if it doesn't have a floppy drive controller on the mobo).

Another possibility - which I've never tried, btw - is to set up DOS to 
be able to read/write to USB memory sticks (thumb drives); such drivers 
do exist for DOS, though they are a tad experimental still. But - with 
that, you could dump the file to the USB stick and then read it back on 
the DOS machine.

Another possibility (though DriveWire would be a better way) would be to 
set up a null-modem cable from the PC to the CoCo, then run term 
software on both ends and transfer from the PC to the CoCo using ZMODEM 
or similar...

On 12/19/2017 06:39 PM, coco-request at maltedmedia.com wrote:
> Message: 8
> Date: Tue, 19 Dec 2017 13:35:49 -0800
> From: Kandur<k at qdv.pw>
> To: CoCoList for Color Computer Enthusiasts<coco at maltedmedia.com>
> Subject: Re: [Coco] Playing games from floppies
> Message-ID:<1519025078.20171219133549 at qdv.pw>
> Content-Type: text/plain; charset=utf-8
> Rich kids bought (and still buying:)  game cartridges,
> poor kids like me bought floppies. That's why I have
> over 100 floppies with coco stuff on them, but no games at all.
> Can you tell me how can I  put games onto my floppies?
> Thanks anyway.
> Kandur

Andrew L. Ayers
Glendale, Arizona

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