Do ROMs with the .a26 file extension work without renaming or converting?

[+wongojack]

Just wondering

[Thomas Jentzsch]

Just wondering

There should be no problem.

[+wongojack]

Cool, thanks for the response!

 

Is this in the manual? I tried to read through it several times to see if it was mentioned - perhaps I was just not finding it.

[Thomas Jentzsch]

I don't think it is mentioned. Just that there are some special extensions which can be used if the auto-detection of bankswitching fails.

Edited April 22, 2011 by Thomas Jentzsch

[SeaGtGruff]

I don't have a Harmony cartridge yet, so the following are just general comments.

 

The actual ROM image contained in the file is the same regardless of the filename extension (.A26, .BIN, etc.), so no "converting" per se should be needed, just renaming the extension. If I remember correctly, some emulators expect the .A26 extension, and might not display any files that have a .BIN extension when you browse to a given folder in the emulator's GUI. However, I don't think it matters what the extension is if you're specifying the name of the ROM file you want to play in the command line for starting up the emulator.

 

Note that the .BIN extension is generic, and doesn't indicate what type of ROM image the file contains (a 2600 ROM, 7800 ROM, ROM for the 8-bit line of Atari computers, etc.), nor does it indicate the cartridge format used (i.e., bankswitching method). The advantage of using the .A26 extension is that it indicates the file contains an Atari 2600 ROM image. Likewise, the .A78 extension indicates the file contains an Atari 7800 ROM image. As long as you're keeping your ROM files organized in separate folders (2600 ROMs in one folder, 7800 ROMs in another folder, etc.), there should be no confusion from using the generic .BIN extension for all of them. If you wanted, you could develop your own system of extensions to help you instantly identify the specific ROM type when you're browsing through your folders-- for example, .A26_E7, .A26_F4, .A26_F6, .A26_F8, and so on. That might throw off some emulators, and possibly programmable multi-carts like the Harmony, but it might not. An alternative (if you want to be able to tell what the ROM type is) would be to just use a generic extension (be it .A26, .BIN, or something else) but have separate subfolders for each ROM type, indicating the bankswitching method in the folder name (strictly for your own benefit). Then you'd just have to be sure you put each ROM file in the appropriate folder. For example, you could organize your ROM files using the following folder names:

 

C:\Atari\2600\ROMs\2k\

C:\Atari\2600\ROMs\4k\

C:\Atari\2600\ROMs\E7\

C:\Atari\2600\ROMs\F4\

C:\Atari\2600\ROMs\F6\

C:\Atari\2600\ROMs\F8\

C:\Atari\7800\ROMs\

etc.

 

Of course, you could also create some other scheme (again, strictly for your own benefit), such as having separate subfolders for the different game companies (Atari, Activision, MNetwork, etc.). As long as you point your emulator's ROM directory path to the main folder name, you should still be able to easily browse to any subfolders.

 

Michael

 

 

 

[+Mitch]

Likewise, the .A78 extension indicates the file contains an Atari 7800 ROM image.

 

Actually the A78 extension indicates it's a 7800 ROM image with a header. The standard 7800 ROM images generally use .bin.

 

Mitch

[SeaGtGruff]

Likewise, the .A78 extension indicates the file contains an Atari 7800 ROM image.

 

Actually the A78 extension indicates it's a 7800 ROM image with a header. The standard 7800 ROM images generally use .bin.

 

Mitch

Is that an emulator thing? I just knew that I'd seen the .A78 extension used with ROMs for an Atari 7800 emulator. I didn't know there was a difference between, say, JOUST.A78 and JOUST.BIN.

 

Michael

[A.J. Franzman]

From the manual and elsewhere in this forum, the Harmony cartridge generally ignores filename extensions, except the following ones that force a particular bankswitching type:

.2K  = Atari 2K
.4K  = Atari 4K (default)
.F8  = Atari F8
.F8S = Atari F8 with Superchip
.F6  = Atari F6
.F6S = Atari F6 with Superchip
.F4  = Atari F4
.F4S = Atari F4 with Superchip
.FA  = CBS RAM +
.FE  = Activision FE
.3F  = Tigervision 3F
.3E  = 3E (3F with up to 4K RAM)
.E0  = Parker Brothers E0
.E7  = M-Network E7
.CV  = CommaVid
.UA  = UA Limited
.AR  = Arcadia Supercharger
.DPC = DPC (Pitfall 2)
.084 = 0840 Econobanking

 

There's also one special filename: AUTORUN

I don't know if it's case-sensitive (probably not). If a file with this name is in the root directory of the SD card, the Harmony menu will be skipped and whatever game has this name will be run. It will not be exactly the same experience as plugging in an original cartridge with that binary, though; the Harmony spinning logo will briefly appear as the game loads. To make the Harmony appear to behave EXACTLY as an original cartridge, the Harmony must be "flashed" with the game binary (replacing the multicart BIOS) using the programming software.

 

I just hope nobody comes along and makes a VCS game that's actually named "AUTORUN"...

Edited April 24, 2011 by A.J. Franzman

[GroovyBee]

Likewise, the .A78 extension indicates the file contains an Atari 7800 ROM image.

 

Actually the A78 extension indicates it's a 7800 ROM image with a header. The standard 7800 ROM images generally use .bin.

 

Mitch

Is that an emulator thing? I just knew that I'd seen the .A78 extension used with ROMs for an Atari 7800 emulator. I didn't know there was a difference between, say, JOUST.A78 and JOUST.BIN.

 

Michael

 

The A78 header is 128 bytes (before the ROM binary data) and contains amongst other things the game's title, ROM image size, MD5 hash, controllers required and cart type (e.g. bank switching, extra RAM, POKEY etc). There are plenty of A78 games with incorrect cart types in the header. They rely on an MD5 hash match in the emulator's database to get the cart type right. I don't think any of the 7800 emulators do heuristics checks on raw *.bin files so any bin files above 48K in size or those that require POKEY or extra RAM probably won't work as expected.

[+batari]

From the manual and elsewhere in this forum, the Harmony cartridge generally ignores filename extensions, except the following ones that force a particular bankswitching type:

.2K  = Atari 2K
.4K  = Atari 4K (default)
.F8  = Atari F8
.F8S = Atari F8 with Superchip
.F6  = Atari F6
.F6S = Atari F6 with Superchip
.F4  = Atari F4
.F4S = Atari F4 with Superchip
.FA  = CBS RAM +
.FE  = Activision FE
.3F  = Tigervision 3F
.3E  = 3E (3F with up to 4K RAM)
.E0  = Parker Brothers E0
.E7  = M-Network E7
.CV  = CommaVid
.UA  = UA Limited
.AR  = Arcadia Supercharger
.DPC = DPC (Pitfall 2)
.084 = 0840 Econobanking

 

There's also one special filename: AUTORUN

I don't know if it's case-sensitive (probably not). If a file with this name is in the root directory of the SD card, the Harmony menu will be skipped and whatever game has this name will be run. It will not be exactly the same experience as plugging in an original cartridge with that binary, though; the Harmony spinning logo will briefly appear as the game loads. To make the Harmony appear to behave EXACTLY as an original cartridge, the Harmony must be "flashed" with the game binary (replacing the multicart BIOS) using the programming software.

 

I just hope nobody comes along and makes a VCS game that's actually named "AUTORUN"...

We've changed the AUTORUN filename to something else (I think AUTOBIN, but I need to check.) The problem was some new SD cards ship with an autorun.inf file on them, and will attempt to load this file into Harmony, which will of course fail.