Coleco gets a bad rap?

[supercat]

The 7800 lockout was even cryptographic and impossible to break without modding the console until five or six years ago when someone dug a hard drive out of a dumpster in Sunnyvale.

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It must have been more than ten years ago, or else there would have been a way to write Atari homebrews without it. The Harry Dodgson monitor cart is 16K (in 7800 mode) but only the top 4K is encrypted. It would have been pretty easy to write a homebrew by copying the last 4K of the Dodgson cart and making the rest be original.

[Bruce Tomlin]

I would have guessed Coleco was doing some sort of cartridge validation during the annoyingly-long power-on screen.  Do they not?

Then you should look at a disassembly of the code some time. It is well known that it's just sitting in a stupid delay loop. I've patched the BIOS on my own CV to check for the left fire button to abort the stupid loop. (this makes It's Only Rock And Roll slightly more playable, too, as it calls the same loop all over the place) Of course I bothered to put a nice Namco-style font in there while I was at it, but some games ignore it and load their only copy of the ugly font anyhow.

 

And if you set the first two bytes of the cartridge the right way, it jumps into the game as soon as possible, without even bothering to shut up the sound chip.

 

That would be true if the goal was to clone the Colecovision.  If the goal were merely to write games that would work with the CV, all it would be necessary to do would be to examine the BIOS enough to determine the cartridge entry point and NMI vectors, and then ignore everything else in the BIOS.  True, a cartridge might be able to save some code by using the BIOS routines, but I wouldn't think they'd really be needed for much.

Kevin Horton didn't use the BIOS at all when he wrote Kevtris. In my RPG, I'm only using a few specific routines, primarily the block move/fill VRAM routines. Which had a bug, by the way, but the bug was burned into ROM, so everybody had to work around it.

 

I will tell you one thing that will blow you away since you clearly don't know much about the ColecoVision internals yet... that BIOS was written by some people who didn't have much Z-80 experience. There was one point where six move instructions were done to swap the DE and HL registers, for which there is already a built-in instruction that doesn't destroy other registers in the process! I have personally optimized over 1K out of its 8K, most of which is contiguous after some rearrangement of code. And it's still compatible, as I disassembled a whole bunch of games to find out where they jumped directly into ROM. As I recall, Interphase was the worst offender. I think they even jumped directly into ROM in places that already had a $1Fxx jump vector! I stuck a simple controller tester into the slack space.

 

There was a file I found since then which I'm not sure whether it was official or not, but it was an equates file for the Adam (which has the same first 8K), and mentioned a few other addresses in the ROM. I've never seen them used in CV games, and I'm not sure whether I should bother to lock down those too, or just put in a switch mod to go back to the original BIOS in the odd chance that someone hooks up an Adam expansion and runs a program that tries to use them. But basically, I've got a nice stack of ColecoVision consoles and power supplies accumulated over the years that I'm going to mod at some point.

[Bruce Tomlin]

The 7800 lockout was even cryptographic and impossible to break without modding the console until five or six years ago when someone dug a hard drive out of a dumpster in Sunnyvale.

It must have been more than ten years ago, or else there would have been a way to write Atari homebrews without it. The Harry Dodgson monitor cart is 16K (in 7800 mode) but only the top 4K is encrypted. It would have been pretty easy to write a homebrew by copying the last 4K of the Dodgson cart and making the rest be original.

He actually got Atari to sign the code, and cleverly wrote it such that there was a back door. That wasn't "breaking" it, it was just a loophole. And it still cost 4K each time you wanted to use it.

 

If Atari had still cared, they could have demanded to see the source code before signing it to make sure that there weren't any obvious back doors like that.

 

And it would be a copyright violation to use it anyhow, as that 4K is Harry's code.

[supercat]

That wasn't "breaking" it, it was just a loophole.  And it still cost 4K each time you wanted to use it.

 

True, but there would have been other ways...

 

If Atari had still cared, they could have demanded to see the source code before signing it to make sure that there weren't any obvious back doors like that.

 

Well, the fact that they only signed the last portion of a larger ROM would be somewhat suggestive. As you note, "had Atari still cared".

 

And it would be a copyright violation to use it anyhow, as that 4K is Harry's code.

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It would have to be licensed from Harry, though--NOT ATARI.

 

Actually, if one wanted to design carts that would work on the 7800, there would be a few ways even if Atari didn't sign anything they 'shouldn't have'.

 

-1- Add a chip to the cart to decode the address of the 7800's main control latch, and have that chip control a really strong pulldown transistor on the data bit that feeds the "disallow changes" bit. IIRC, the 7800 they writes a "1" to disallow further changes; an NMOS CPU shouldn't mind too much having its "1" output externally driven low.

 

-2- If one could find any working cartridge whose creator didn't mind your using their work, build a bank-switched cart which looks for an access to a particular address and then switches to a different ROM. Have the cart power up in the "old" game. Once the 7800 has validated the code, switch to the new one.

 

-3- If you can't find someone who's willing to let you use their code, but you can find a lot of cheap carts of some 7800 game, yank the ROMs out of that cart and solder them into a bank-switch cart similar to the above, but where the logic switches between two ROMs. Expensive, but if games were selling for $30+ each it wouldn't be impossible.

 

-4- Sell a "game booster" peripheral which includes some RAM, a POKEY, and other goodies along with a scavenged ROM from another game as in #3. Then sell your games themselves in a cart form factor which plugs into the booster. If the booster didn't have to fit a standard cart form factor, it could probably use the PCB from the scavenged game without modification.

[Atariboy2600]

TO me I always see Coleco had cheated all of us for the 2600 games, as the other 3rd party games was trying to do there best of porting any arcade games for the 2600 Coleco did excatally the opposite by making there game very crappy and try to make the 2600 look bad and to me thats very sad in the end, who knows how good Donkey Kong or Zaxxon could had came out right if they even tryed

Edited January 21, 2006 by Atariboy2600

[supercat]

who knows how good Donkey Kong or Zaxxon could had came out right if they even tryed

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DASM is freely available, as are all the development docs you need. Why don't you demonstrate how well you can code Donkey Kong in 4K. Good luck.

 

BTW, I think Gary Kitchen might have been willing to do a fair bit better if he'd been willing to leave out the hammer. Not sure what his contract specified, but the hammer actually takes up an awful lot of code. I would guess that if the hammer had been omitted, there would have been enough code space to support vertically-moving fireballs (though those might have been too nasty in the absense of the hammer).

[vdub_bobby]

I agree that DK is really done *almost* as well as it could be done in 4K.

 

IMO the hammer is too integral to leave out, though.

[Atariboy2600]

who knows how good Donkey Kong or Zaxxon could had came out right if they even tryed

1003879[/snapback]

 

DASM is freely available, as are all the development docs you need. Why don't you demonstrate how well you can code Donkey Kong in 4K. Good luck.

 

BTW, I think Gary Kitchen might have been willing to do a fair bit better if he'd been willing to leave out the hammer. Not sure what his contract specified, but the hammer actually takes up an awful lot of code. I would guess that if the hammer had been omitted, there would have been enough code space to support vertically-moving fireballs (though those might have been too nasty in the absense of the hammer).

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Wait when did the 8k games came out? Coleco could had use them.

[shadow460]

So my original question has been answered...Coleco probably does get a bad rap...next question:

 

Out of the 3rd party developers that did primarily arcade conversions, which one would be better than Coleco...CBS? Sega? Parker Bros? Those three come to mind, especially CBS and Sega, but I'm not sure if they were better than Coleco.

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I'd say out of those three, Parker Bros. was the best. I just couldn't get into gorf and Wizard of Wor, and I think CBS should have ditched the Booster Grip in Omega Race for Asteroids type controls. Then again, maybe they packed the Booster Grip into that game so that more people would have it available (and be used to using it) when Wings came out.

 

I feel kinda the same way about Sega, too. Their overlay for Star Trek was less useful than the Booster Grip. Also, most of their games were just bland. Star Trek seemed to have me focused more on the map than the crosshairs while Sub Scan and Buck Rogers just weren't my thing.

 

Tac-Scan and Solar Fox are simply awesome no matter how you look at it. But that's just one game from each company that I had available then. My parents were iffy about R rated movies, so you know there was zero chance of us ever owning Tapper.

 

Parker Bros, on the other hand, had great ports of Reactor and Star Wars the Arcade Game. Their Frogger was good, too, but far outclassed by the Starpath version. Yeah, they stunk up Q-Bert and Amidar pretty bad (there are supposed to be dots in the gorilla mazes), but still they did well on many others.

Sky Skipper was madly addicting for a while, and while the Empire Strikes ack and Jedi Arena might not have even been arcade games, they could pass for arcade. Ditto for Cobra Strike.

 

Really, though, for arcade conversions, the ones we enjoyed the most were made by big daddy Atari.

[Student Driver]

On Coleco games for 2600 in general: I was very "meh" about their titles when I was a kid, and am still kinda "meh" about them now. I think I'm in the minority for not even liking Smurf: Rescue in Gargamel's Castle. Their tabletop games were the bee's knees, though.

 

That said, I didn't think 2600 Zaxxon was all that horrible. The arcade's perspective was obviously undoable, and their compromise makes sense. I first played it after I'd become a frequent player of Zaxxon 3D on my SMS, so the 2600's gameplay felt like a legit Zaxxon game, if not a legit arcade translation.

 

Of other arcade-adapting companies, I'll have to throw my hat into the Atari ring as well. Their conversions in the silver-label era are stunning...

[NovaXpress]

Tac-Scan and Solar Fox are simply awesome no matter how you look at it. But that's just one game from each company that I had available then.

Here we go. Tac-Scan and Solar Fox are great 2600 games, but they were Godawful translations of the originals. As far as replicating the arcade experience goes, these two games were worse than Pac-Man or Donkey Kong.

 

But few people know that because few people ever saw Tac-Scan or Solar fox in the arcades. If Tac-Scan had been a monster hit, the 2600 version would have made you angrier than Pac-Man ever did. Tac-Scan has one level out of the original three, only one type of enemy, and they completely dropped the 3D effect (the same way Zaxxon did). Solar Fox is so far off from the arcade there's no sense in going into it.

 

But few of you see this because you weren't fans of the original. But with so many Defender and Pac-Man fans out there, those games take all the heat for their shortcomings.

[supercat]

Wait when did the 8k games came out? Coleco could had use them.

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There are two ways to produce an 8K game using F8 bankswitching (the most common method)

 

-1- Design a custom ROM chip which has the 8K bankswitching hardware built in

 

-2- Build a cart which contains three chips in addition to the ROM chip

 

Atari used the first approach for Asteroids. They knew they'd be making game cartridges for awhile, so even if the $tens of thousands they had to spend on engineering weren't recouped in Asteroids sales, they'd be recoupled in sales of other 8K carts. And of course, one Atari had done Asteroids, using the same approach for other 8K carts was a no-brainer.

 

I don't think any third-party vendor had yet used an 8K cart when Donkey Kong came on scene. When it became clear that 8K carts would be necessary for companies wanting to remain competitive, some companies invested in custom silicon while others went with multi-chip solutions. The market had not yet reached that point, however, when Donkey Kong debuted.

 

BTW, I think I've figured out a way to do an 8K bank-switch cart using one 4016, three resistors, and a cap. Not sure the design would have been 'trusted' in 1981, though.

[8th lutz]

Wait when did the 8k games came out? Coleco could had use them.

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I think they did in 1983 or 1984.

[NovaXpress]

More like Asteroids in 1981, as supercat explained above.

 

Who was the first third-party to go 8K? None of them did until 1983 did they?

[8th lutz]

More like Asteroids in 1981, as supercat explained above.

 

Who was the first third-party to go 8K? None of them did until 1983 did they?

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I don't think so before 1983. If a third party did it before 1983 had to be activision. I think it had to be activision or cbs games. I think cbs games was possibility for that or they just went to 12k games right away.

[NovaXpress]

CBS started at 4K with Gorf and Wizard of Wor.

 

First 8K third-party is probably Parker Bros.

[NE146]

Yeah, they stunk up Q-Bert

 

I really disagree with this. Q-Bert is one of the only arcade ports on the 2600 where you could "practice at home", then your skills would directly translate to the arcade!

 

I was really good at Q-Bert in the arcades, and I owe it all to my practice time on the 2600 version. Name another 2600 game that does that. Certainly not Space Invaders.

[Inky]

I agree with NE... 2600 QBert was pretty dang good, for the limited graphics on the 2600. Its one title I still play to this day.

[George Gray]

Sorry, but CBS games is NOT the Columbia Broadcasting System - or CBS TV.

It is the European arm of Coleco. Check here AtariAge Coleco page

and here Intv Funhouse's CBS page

Sorry but that's not true. The CBS which released Gorf, Wizard of War, Blue Print,and those other US releases with the distinctive box is not Coleco.

 

Look at the manuals:

CBS Toys, A Division of CBS, Inc., Newark, NJ 07105 2L-2205

Why did they have the license to John Madden, CBS commentator?

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While I'm still not completely convinced, I will concede to you for now. I've scoured everything I've found about the various CBS Network owned companies and not found any mention of a 'CBS Electronics' that manufactured and sold video games. The only CBS Electronics references I found were from 1948-1963. That CBS made, among other things, appliances (refrigerators) and the infamous CBS color wheel to be used with a special 405 line CBS made television during the ill-fated FCC approved mechanical color system for US television. Obviously, the guru's figured the American public to be a bunch of dopes and actually trash the $400 bw tv's they already bought for a quasi-mechanical television and mediocre color. No, we were smarter than that. We setteled for mediocre ALL ELECTRONIC color. So there, CBS!

Anyway, I digress. I cannot argue with a legit manual either. I found a similar entry here on Atari Age. So, for now, I'll shut up about it.

CBS was quite the company. Bought, sold, bought, sold...several times. Now, they are independent again as Paramount has split it out again. Personally, I wish that Ted Turner had gotten his way in 1985 and bought it.

 

Oh, Parker Bros had the best 3rd conversions. Q*Bert was great.

[NovaXpress]

CBS question taken care of in the new thread, I'm happy to correct some false rumors. I'm also the guy who made a stink until everyone recognized that Adventure was not the first easter egg.

 

I also vote for Parker Bros.

[supercat]

CBS question taken care of in the new thread, I'm happy to correct some false rumors. I'm also the guy who made a stink until everyone recognized that Adventure was not the first easter egg.

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If other posted comments are to be believed, Adventure should retain its distinction as being the Easter egg that was put in the code for the purpose of being discovered by someone other than the author.

[NovaXpress]

How could one possibly prove that distinction? The Adventure egg isn't any easier to find than the Fairchild eggs were. Robinette never intended to make this the most seen egg off all time. If the solution hadn't been printed in Electronic Games, Adventure's egg wouldn't have been such a hype at the time.

[supercat]

How could one possibly prove that distinction? The Adventure egg isn't any easier to find than the Fairchild eggs were. Robinette never intended to make this the most seen egg off all time. If the solution hadn't been printed in Electronic Games, Adventure's egg wouldn't have been such a hype at the time.

1004854[/snapback]

 

According to some stories, the author of the Fairchild games would sometimes go into a store and pop up the Easter egg. If there is any confirmation of that, that would prove the distinction.

 

Otherwise, I would argue that the Adventure egg's design left some real clues as to its whereabouts:

 

-1- Observable behavior: Rooms with the surround flicker with more than one object; rooms without the surround flicker with more than two.

 

-2- The magic dot room flickers with only one object and the surround; that suggests the existence of another item somewhere.

 

-3- Exploring the room carefully will reveal that there is another item: a grey dot.

 

-4- The right-hand wall in the 'secret room' entryway can color according to the color of objects within it.

 

-5- Placing a gray dot in such a room would cause the wall to turn the same color of gray as the background and thus disappear.

 

So a person who played the game and was familiar with it would have reason to believe there might be something "interesting" going on, and would have reason to explore what that was. Do the Fairchild easter eggs provide any clue as to their existence?

[Lord Helmet]

Q*Bert is an excellent translation. Still alot of fun to this day. The pyramid might not be perfect, but it's the 2600 for crying out loud! The gameplay is spot-on.

[BrianC]

Tac-Scan and Solar Fox are simply awesome no matter how you look at it. But that's just one game from each company that I had available then.

Here we go. Tac-Scan and Solar Fox are great 2600 games, but they were Godawful translations of the originals. As far as replicating the arcade experience goes, these two games were worse than Pac-Man or Donkey Kong.

 

But few people know that because few people ever saw Tac-Scan or Solar fox in the arcades. If Tac-Scan had been a monster hit, the 2600 version would have made you angrier than Pac-Man ever did. Tac-Scan has one level out of the original three, only one type of enemy, and they completely dropped the 3D effect (the same way Zaxxon did). Solar Fox is so far off from the arcade there's no sense in going into it.

 

Tac-Scan 2600 may have only one level, but one level in the arcade is simply the same as the first with a 3D effect and the third level is very brief (though I think it should have been attempted). The difficulty progression is different in Tac-Scan 2600 too. The game has a more noticeable difficulty push after each level and gets harder much faster.

 

Tac-Scan dropping the 3D is NOT the same as Zaxxon switching from isometric to 3D. Zaxxon didn't drop a 3D effect, it switched from isometric to a 3D perspective. I'm actually glad the second stage in Tac-Scan wasn't attempted on the 2600, since it's just the first one in 3D and might not translate well to the 2600. However, I think the third level could have been done in the 2D style.

 

Anyway, Tac-Scan is not an accurate translation, but worse than Pac-Man and Donkey Kong? It's quite a different beast from the original and missing elements, but it does keep some of the feel of the arcade intact and I feel the different difficulty curve makes up for the missing boards. I actually don't miss board 2 much at all.

 

Solar Fox may not be close to the arcade, but comparing it to Pac-Man? Unlike Pac-Man, it still has much of the fun of the arcade game intact. It is missing quite a few of the elements like the whirpools and bonus items, but the 2600 version is still far from a awful translation. It still has level progression and bonus rounds intact too. No sense in going into it? By that logic, there is no sense in going in to the NES versions of Contra or Life Force either. It may be different from the arcade, but it still keeps some of the charm intact and is quite fun on its own.

Edited May 29, 2006 by BrianC