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Alternate ColecoVision BIOSes?

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Hello,

 

I'm trying to learn more about the ColecoVision console, and I'm perplexed by something. Seems like someone here may know the answer.

 

Basically, if when you emulate the ColecoVision (in MESS, for example), you can install one of two BIOSes, both of which are pretty easy to find. The main difference between the two, it seems, is the system font they each include. The original is a sparse, pretty generic character set, and the alternate (usually labeled "ColecoVision BIOS (Different Font)" is a much more distinctive, wide-lettered typeface. It's almost script-like in some letters.

 

I haven't tried to disassemble either yet, but I can tell there are some other differences besides the font.

 

So, does anyone know why there are two? For example, Is the different BIOS from the Telegames or CBS Electronics version?

 

Thanks.

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From my days of ColEm/2, I seem to recall the other BIOS would let you skip the initial splash screen delay when you first powered up the unit.

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There are 3 ColecoVision BIOS files that I know of:

 

Standard - (obvious)

 

Different Font - (obvious)

 

"Intro Skip" - (allows user to skip the title screen of any Coleco published game by pressing either one of the controllers' left fire buttons (yellow button on a SAC))

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There are 3 ColecoVision BIOS files that I know of:

 

Standard - (obvious)

 

Different Font - (obvious)

 

"Intro Skip" - (allows user to skip the title screen of any Coleco published game by pressing either one of the controllers' left fire buttons (yellow button on a SAC))

 

So, any idea if these originated with specific ColecoVision iterations? I mean, for example, did the different font one come with the Telegames Personal Arcade?

 

The wikipedia article on DINA says its startup screen included japanese text. If so, it's worth noting that I couldn't find any Japanese characters (certainly not a full character set) in any of these three ROMs.

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Not sure about the different font rom, but it's probably safe to say the intro skip rom was just a hack by someone who got sick of that ridiculous 12-second wait.

 

--Zero

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Basically, if when you emulate the ColecoVision (in MESS, for example), you can install one of two BIOSes, both of which are pretty easy to find. The main difference between the two, it seems, is the system font they each include. The original is a sparse, pretty generic character set, and the alternate (usually labeled "ColecoVision BIOS (Different Font)" is a much more distinctive, wide-lettered typeface. It's almost script-like in some letters.

I can tell you exactly why:

 

1) the original font sucks, especially in the lower-case

2) the stupid ten-second startup delay

 

Beyond that there isn't much except the challenge of optimizing the crappy code for the fun of it:

 

http://xi6.com/code/coleco/coleco29.asm

 

It's an 8K ROM and I was able to free up 1K of mostly contiguous space, in spite of all the games that jump directly into ROM. There was even one place where some idiot did six move instructions instead of EX DE,HL. You have to be a serious 8080/Z80 noob to not know that.

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I can tell you exactly why:

 

1) the original font sucks, especially in the lower-case

2) the stupid ten-second startup delay

 

No argument there.

 

So are you saying the alternate font was a recent hack as well?

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Basically, if when you emulate the ColecoVision (in MESS, for example), you can install one of two BIOSes, both of which are pretty easy to find. The main difference between the two, it seems, is the system font they each include. The original is a sparse, pretty generic character set, and the alternate (usually labeled "ColecoVision BIOS (Different Font)" is a much more distinctive, wide-lettered typeface. It's almost script-like in some letters.

I can tell you exactly why:

 

1) the original font sucks, especially in the lower-case

2) the stupid ten-second startup delay

 

Beyond that there isn't much except the challenge of optimizing the crappy code for the fun of it:

 

http://xi6.com/code/coleco/coleco29.asm

 

It's an 8K ROM and I was able to free up 1K of mostly contiguous space, in spite of all the games that jump directly into ROM. There was even one place where some idiot did six move instructions instead of EX DE,HL. You have to be a serious 8080/Z80 noob to not know that.

So Bruce, is your modified BIOS code one of the compiled versions that we find in the wild today? Is the 1K of space you saved available to games if the game is programmed accordingly?

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Hi there, this is my first post here. I know this thread is old, but the question was never really answered. Is colecoa.rom a legitimate bios dump or just a hack?

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