[Coco] Help with MacMAME

[Andrew Ayers]

Ok - so after a bit of experimentation with my system configuration, 
here is what I have found - and I think this is correct, so please bear 
with me here, and try to follow (it's confusing to me a bit):

This is what I have in my .desktop file to start my CoCo 3 mame machine:

	Exec=/usr/games/mame -w coco3

This part would not apply of course to the Mac (and MacMAME); but I just 
wanted to show how my Mame is "configured" from "the beginning" to run 
my CoCo 3 emulation. Testing at the command line via a terminal window 
(tilex in my case) just to verify things, ie:

	$ /user/games/mame -w coco3

...worked the same as the .desktop file (which is what gets executed 
from "the menu").

Note that the "-w" flag is to make Mame use a window, instead of going 
"fullscreen", because I use Mame so little, I forget the key combo for 
getting to an "exit menu"...plus full screen isn't very useful when you 
are also looking things up in a browser, etc, etc...

So..."coco3" must refer to the .zip file in my Mame /roms directory 
named "coco3.zip". It has inside:

	coco3.rom		(32768 bytes)
	coco3.txt		(94 bytes)
	disk11.rom		(8192 bytes)

Note the file sizes for the rom files inside the zip file; they are 
essentially (I think) the "exact duplicate" of the data that would be 
put into the equivalent sized EPROMs (27C256 and 27C32); that is, you 
could use these files with the an EPROM burner, then install them into a 
real CoCo (more or less).

So, you can see this is a pretty "bare bones" configuration; in fact, 
it's identical to what you would have with a regular CoCo 3, with a 
standard Tandy FD-50x floppy drive controller, to boot to SDECB 2.1 
(which shows a banner of "DISK EXTENDED COLOR BASIC 2.1" at startup; I 
think normally, iirc, without a floppy drive controller the CoCo 3 shows 
a banner of "SUPER EXTENDED COLOR BASIC x.x" (I forget the version 
number it shows, maybe 2.0?)

The ASCII text file, IIRC (it's been a while since I last looked at any 
of this), was something I put into the zip file to "label" what the roms 
for the "machine" are; in this case, it reads:

	Computer:      Color Computer 3 (NTSC)
	Manufacturer:  Tandy Radio Shack
	Year:          1986

Again - I may be wrong about what and how that text file was put in 
there; regardless, I don't believe it a necessary piece, as the other 
rom zip files don't all have a similar file (some do, some don't).

As a "sanity test" - I removed all the rom zip files from my roms 
directory, except for "coco3.zip" - then executed Mame from the command 
line ("mame -w coco3") - and it still worked; so you just need a zip 
file with those two rom images included.

**** NOTE HERE ****

I then tried to create a new rom zip file with just the "coco3.rom" 
inside, thinking that I could start up Mame as a "bare bones" CoCo 3; 
that is, one with just the CoCo 3 rom, and not the floppy 
controller...when I did that...whoa, it shows "DISK EXTENDED COLOR BASIC 
2.1"...???

So I tried removing that zip file from the roms directory, restarted 
Mame...and the same thing happened; it was still working...so...huh?

Then I did some more checking...

The only other thing I saw is what I think is a "slightly customized" 
.ini file for the "coco3"; it is located in my $HOME/.mame directory, 
named "coco3.ini". The only difference I see between it, and the default 
"mame.ini" file, is that I have added to the beginning of the "CORE 
SEARCH PATH OPTIONS" for the key of "rompath", is the string 
"$HOME/apps/mame/roms/coco" (separated from the "defaults" by a 
semicolon). I initially thought this was to have a custom place to put 
various game rom files, so they didn't clutter up my "machine emulation 
roms" (that's the only reason I can think of).

But I looked inside it...and it actually contained the same set of CoCo 
3 rom files (I also noted that in "$HOME/apps/mame/roms" there were 
other subdirectories of "/arcade" (containing various arcade game 
machine roms) and one called "/neogeo", with roms for that system (I'm 
not sure if they are for the arcade machine, or the console)...

So I must've set things up in my .ini file (coco3.ini) to look in that 
directory before the default roms directory; I am not sure if the 
"coco3.ini" file is generated automatically, or if it was something I 
copied from the default "mame.ini" file and modified, or...??? But I 
have a fairly custom configuration; I wanted to use Mame for not just my 
CoCo - but for those other games and other systems, I guess...?

I tested things out further by renaming the "coco3.zip" file to 
something else, and then trying to start Mame up again - and this time 
it failed to run (and gave me a message, interestingly, of "emulations" 
it found as "similar"); I found that strange - where does it get that 
information?

So I then tried to run a "modified" coco3.zip file, with just the 
"coco3.rom" image in it, without the floppy rom image...and when I ran 
Mame - it complained about not having a floppy rom image! So here is 
what I think (???) is happening (maybe Tim Lidner can chime in?):

Mame is using some kind of "internal list"; I am making an assumption 
that this list is "baked into" Mame - that is, hard coded in the source 
files for the Mame executable (because in that list of suggestions it 
gave that I mentioned previously, one of the suggestions was for "cc3" - 
some kind of system called a "Chess Challenger 3" by "Fidelity 
Electronics, 1977" - which I have nothing like that anywhere in my 
system)...unless there is some configuration file elsewhere of "all 
possible Mame emulations"...

So anyhow, this list assumes that the "CoCo 3" emulation rom zip file 
*MUST* also contain the floppy disk controller rom image (which I find 
odd; no where in the "suggestions" was anything of a "bare CoCo 3" - I 
don't know why this is; that seems to be an oversight, because what if 
you want, say, a "CoCo 3 with the Robocop cartridge" and nothing else? 
Why do you -need- the floppy controller rom?)

I know the above might be a bit confusing, but I hope all the extra 
detail might help...
Andrew L. Ayers
Glendale, Arizona
phoenixgarage.org
github.com/andrew-ayers

On 3/24/25 1:08 PM, coco-request at maltedmedia.com wrote:
> 
> Message: 2
> Date: Mon, 24 Mar 2025 10:26:51 +0100
> From: Tony Schountz <schountz at gmail.com>
> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> Subject: Re: [Coco] Help with MacMAME
> Message-ID:
> 	<CAAsy49A5jE5eVn-TuCsS6zoj0D3+8RE4CuUdGbvOhUB3O_+46A at mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
> 
> Thanks much, led to  progress. However, now MAME is telling me other rom
> files are missing. On exit, this shows up in terminal:
> 
> System media audit failed:
> coco3.rom (32768 bytes) - INCORRECT LENGTH: 258 bytes
> disk10.rom (8192 bytes) - NOT FOUND (coco_fdc)
> disk11.rom (8192 bytes) - NOT FOUND (coco_fdc)
> ados.rom (8192 bytes) - NOT FOUND (coco_fdc)
> ados2b.rom (8192 bytes) - NOT FOUND (coco_fdc)
> ados3.rom (8192 bytes) - NOT FOUND (coco_fdc)
> ados3-40.rom (8192 bytes) - NOT FOUND (coco_fdc)
> ados3-80.rom (8192 bytes) - NOT FOUND (coco_fdc)
> rgbdos_mess.rom (8192 bytes) - NOT FOUND (coco_fdc)
> hdbdw3bck.rom (8192 bytes) - NOT FOUND (coco_fdc)
> hdbdw3bc3.rom (8192 bytes) - NOT FOUND (coco_fdc)
> 
> I have the Coco3 rom from both mine that I used with MESS before and the
> one from the Coco Archive but both report incorrect length. I found disk10
> and disk11 roms on CC Archive but not the others. I'm not sure why I need
> all of them; my recollection with MESS was that all I needed was the
> coco3.rom or coco3h.rom. Can you copy a list of the rom files you have in
> your roms folder?