Original subtitles

Full ROM sets in MIM are a great way of

getting you up and running, but

sometimes you just want to load the

games you really want to play without

the thousands of others. Let me show you

how to create your own custom ROM set.

[Music]

Hi, and welcome to Bites and Bits.

Playing arcade games on your computer or

your modded console or even your

handheld devices is great fun, but

getting it all set up can be a bit of a

nightmare. For most systems, you'll be

using the MIM emulator, which offers

fantastic emulation, but has a confusing

game file structure. Now, in most of my

videos, I advise using a full ROM set

download, which bypasses any

compatibility issues, but this comes at

the cost of having tens of gigabytes of

game files with thousands of games that

you either don't want or will never

play. So, in this video, I'll show you

how to cut this down to just the games

you want. So, let's create a custom MIM

ROM set.

So first we need to have a quick

overview of how MIM ROM files are

organized. Now I did make a full video

on this topic a while back. So please do

refer to that for a more in-depth

explanation.

Now essentially MIM has to emulate

literally thousands of arcade cabinets

which means that there are endless

combinations of motherboards,

processors, IO devices, screen layouts

and so on. Now, some cabinets were

reused for other games, but again tended

to be slightly modified to create clone

cabinets and clone games. So, this gives

us a hierarchy of ROM files. So, a

cabinet might have a common set of

components for all the games that run on

it. And we can think of these ROM files

as sort of like the BIOS device, the

base system. You then have the first

game to be built using the cabinet with

its own unique parts. So this game

becomes a parent ROM and the game

cabinet then gets modified and reused in

more games which each one having their

own custom parts but they're mostly then

of course based on that parent hardware

and we call these ones clones. So for a

clone game to be emulated you need to

have the clone ROM files, the parent ROM

files and any BIOS files. So this

creates tens of thousands of ROM files.

So there was an attempt to organize them

to keep the total file size down for a

full ROM set. And this gave rise to

things called split, merged and

non-merged ROM sets. So in essence,

split and merged ROM sets try to

minimize duplication. So any particular

ROM dump is only saved once in the ROM

set, but they do mean that for a single

game to run, you will need to have all

the other files it depends on as well.

What files you need can get a bit

complicated to work out. Fully

non-merged ROM sets ignore this file

size issue and simply create one ROM

file per game that has everything needed

to get that game running. So the BIOS,

parent, and clone files are all in this

one single ROM. And these are the ROM

sets that we need to get hold of.

Now, MAM of course does add a further

complication to our files. So, the MIM

system is continually growing and

improving with new ROM dumps and better

emulation with each new version. This

means that ROM files can sometimes only

work with specific versions of main. So,

we need to make sure that we use a ROM

set that matches the version of MAM

we're using.

for a lot of emulation systems. Um, MIAM

version not.78, which is also MIAM 2003

is the preferred version. So,

RetroArchch uses this as one of its main

MAM cores. Um, Xbox and PlayStation 3

emulators use this and a whole lot of

handheld devices which are usually based

around RetroArchch that they use this

version of MIM as well. So, that's what

we're going to be using to build our

custom ROM set. Now, the best place to

find the files is on the internet

archive. So, here I've searched for MIM

2003 non-merged ROMs. And as you can

see, there are some options we can

choose from. Now, obviously, um you do

need to check that you have permission

to download any software files as many

of these games will still be under

copyright, but I'm going to leave you to

check that for yourself. I'm just going

to assume that you have obtained a full

ROM set.

So once you've got hold of a full ROM

set, um you may well find that you get

that as a single archive or or zip file

and you need to extract that into a

folder on your computer so that we can

see the individual ROMs. Now these ROMs

will also be zip files but but don't

extract them. And you should really see

something like this. So, so you may have

some folders at the top of your list and

these are what are known as CHD files.

So, these are yet another type of dump

that may makes use of for some games and

and they tend to be for later games and

these contain sort of CD and DVD images.

They they match ROM files by file name.

So, here we have a folder called Cal

Speed and that then will match with the

cal speed.zip zip ROM file and that then

of course is for the game called

California Speed.

Now each of these ROM files then should

now contain a complete game. So all we

need to do is to copy out the game files

we need for our custom ROM set folder.

Um but I'm going to be doing this in a

way that will let us actually test these

games just to make sure that everything

is working.

So the best way to test ROMs is to

actually try running them in MIM. Now if

we go to the MIM website, we can

actually get hold of any version of MIM

that we want from the previous version

section. So we're going to scroll down

here until we find MIME 2003 or MIM

version not.78.

So I'm running on a Windows PC. So I can

just simply download the Windows binary

version then and save that. I can then

extract the files and that will now give

me a working copy of MIM not.78.

Now if I look inside the MIM folders

that is created, you'll see that there

is a ROMs folder and then this is where

MIM expects to find its ROM files. So

I'm going to be using this folder. So

the one inside the MIM folder to

assemble my custom ROM set. I can then

use this downloaded version of MIM to

test the files and just to make sure

that everything is there and that

they're actually going to work. So, all

we do now is to simply copy over the

games that we want into this ROMs

folder.

Now, a a lot of the ROM file names will

make it quite easy to identify which

game it is, but some of them can be a

little bit confusing. So, so the best

place to get help for anything to do

with MIM files is the arcade database.

Now, this lists all the games MIM can

emulate and shows you file names,

dependencies, and the actual dump files

required for each game. So, you can

search here for a game by name, pull up

its details, and then in the main data

section, the ROM set name actually tells

you the zip file name you're looking

for. So, in this case, I want to play

the midway version of Pac-Man on my

computer. So, here it shows me then that

I'll be looking for a file called

Pac-Man and then dotzip at the end of

it. So, you just simply need to go

through, find all the games that you

want to copy, identify which zip files

they are, and then move those across

into that ROMs folder.

So once we've assembled our custom ROM

pack then um it's worth just um testing

out a few G games just to make sure that

they're going to work before we then

commit to transferring them over to our

console. So to do this on a Windows PC

um I simply need to use my file explorer

to open up the MIME.78 folder. So that's

the one that we just downloaded and

extracted. And again inside there we

have our ROMs folder where we've been um

putting all of our custom ROMs into it.

So this version of MIM actually runs

from the command line. We don't have any

sort of graphic interface for this. So

we're going to need to open up a

terminal window in this folder. So the

easiest way to do that is to click up

here in file explorer in the path

display. And when you click in there at

the end of it, you should get it to turn

into a text version of the folder

location. So, all we have to do here is

to delete what's in there and type cmd

followed by return. And this will

instruct file explorer to open up a

command prompt in the folder that we

want. So, we should now have a command

window. And we can now run any game by

simply typing the command mim followed

by the game file name. But again, we

don't need to use the dotzip at the end

of it. So, if I want to try out my

midway version of Pac-Man, I just simply

need to type in mim Pac-Man. And if I

press return, if everything is all set

up correctly, we should get Pac-Man up

and running.

Now, if you have a properly formatted,

fully non-merged ROM set, um these games

should all run correctly. But sometimes

you will find that for whatever reason

perhaps a a file has got missed or or a

parent ROM hasn't been included um when

you run a game using MIM um if it hasn't

got all the files in the ROM set that it

needs it will show you exactly which

ones are missing. So again um if you

have got missing files then the best

place to find out where those files

should be is through the arcade

database. So, it actually does list all

of the BIOS and parent files that should

be included in your game files. So, as I

say, if you have got some files missing,

the chances are it is going to be either

a parent or a BIOS file that hasn't been

copied across correctly. So, you simply

need to go and find those particular zip

files and just put those into your

custom ROM set folder. Um, you don't

need to copy out individual files out of

the actual zip files. So when MIM boots

up, it understands that if it doesn't

find the file it needs in the game zip

file, it will then search for parent

files and BIOS files and try and look

for them there. So it should all then

just start working properly.

So now that you've got your custom ROM

set files all assembled, um all we need

to do now is to transfer them to well

whatever system you're going to be

playing with them on. So, I'm going to

use these ones to put them onto my Xbox

360. So, I've just been playing around

with that recently for installing MIM.

So, let's transfer those files across

into the ROMs folder in my MIM

installation on my Xbox 360. And let's

see if all those games come up and we

can play them.

So, all I've done here is just do a

basic file copy of my ROMs folder into

the matching ROMs folder inside the MIAM

folder in my Xbox. And again, you can

just see that's just the file simply

copied across. So, if I now boot up MIM

on my Xbox and go to that, you can see

here that we have our games listed. So,

all I need to do now is to simply select

the one I want to play. And that should

then have everything that that um game

needs all built into my new ROM set. And

I've now got that game up and running.

So I now have the ability to just simply

select what games I want and build up a

nice personalized um minimalized uh ROM

set just with just games that I want to

play. So I hope you found this useful.

Um, you can use this, of course, for any

um system that uses MAM or or MIME

formatted um ROM files. Uh, and just

copy the files to where they're supposed

to be. So, um, if you find this useful,

please do click that like button and

make sure you subscribe to my channel

for more gaming, modding, electronics,

and making projects. I look forward to

seeing you again very soon. And bye for

now.

For more games, programming, electronics

projects, and retro gaming, please make

sure you like this video, subscribe to

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