Question on CV expansion ports and adapters

[Reed Solomon]

I've been thinking lately about how Coleco designed their Atari adapter for the Colecovision. Since the Coleco has a 30 pin cartridge slot and the Atari had 24 pins, certainly they couldn't reuse the cartridge slot and had to have another one, but couldn't they have done something like Sega did with the Genesis Power base converter? Or like those retrobit converters for the SNES?

 

Would it possible to design an Atari converter that clips on the cartridge slot rather than the expansion slot and simply reuses the colecovisions controller ports? Maybe using something like the chip in the Atari Flashback 2? I know even the NES can do it since the retrovision gameboy adapter exists.

 

I know there was a rumoured Intellivision adapter for the Coleco that never made it to production.. Would they have made it in the same way as the Atari Expansion adapter? Have any prototypes ever been seen?

 

Is there a technical reason the Atari adapter that uses the expansion port can't use the coleco joystick ports? Or did they just figure it'd be cheaper and easier to throw in the atari parts into one device and use the expansion port since it exists.I mean

 

[Pixelboy]

If you look closely, there's more to the Expansion Module #1 than just the Atari cartridge port. There are also buttons which are found on the Atari console (left/right difficulty, color/black-and-white switch, game select button, etc.). So even if Coleco had made a module that plugs into the ColecoVision cartridge port, it would still have been a rather bulky module, and it would have towered on top of the ColecoVision console in a rather ugly way.

 

Also, the ColecoVision's joystick ports are not compatible with Atari paddle controllers. So I would guess that's the main reason why Coleco included extra joystick ports on the Expansion Module #1.

 

EDIT: Also, the front expansion port of the ColecoVision allows for any module plugged into it to output its own audio/video signals and circumvent the ColecoVision's video display processor. This is essential for an Atari 2600 adaptor to work, because the ColecoVision's video display processor is completely incompatible with the way the Atari 2600 works in terms of video output.

[NIAD]

There have been reports that an Intellivision Adapter or two exist in prototype stage and are in the hands of a former employee, but that's all that I have ever heard. I'm sure it would have used the front Expansion Bus just like the Atari adapter and been a complete Intellivision sans it's own power supply and RF output.

[Kamshaft]

Someone should totally make an Intellivision expansion! I'd be all over that!

[ValkerieSilk]

Someone is working on that...

 

 

[Kamshaft]

Is there a thread ?

 

 

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[ValkerieSilk]

That would sure be awesome to see.

 

 

[ValkerieSilk]

http://atariage.com/forums/topic/235420-intellivision-expansion-module-for-colecovision/

 

 

Is there a thread ?


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[Hannacek]

They designed the ColecoVision expansion port specifically to be used for the 2600 adapter, and other expansion modules they would release later on. Consoles like the 5200 and Intellivision that had no expansion port were forced to use the cartridge slot as the last resort for their 2600 adapter.

[ValkerieSilk]

The Intellivsion did (does) have an expansion port. In fact, they have a 2600 adapter (system changer) as well, the Intellivoice, a music synthesizer and a computer module. They even had a cable hook up (Playcable) that let you play some of the very first (eh online) games. The 5200 had a 2600 adapter as well, but that did use the cart slot (and had to be modified for the 4 port models I think it was).

 

 

http://www.intellivisionworld.com/english/Hardware/

[juice2839]

The Atari adapter for the Colecovision is a piece of work. It really is just an Atari 2600 in a different case. Pretty much none of the CV hardware is used at all when it's plugged in. The CV is just a pass through to the RF converter. Back in the 80's the adapter cost near as much as a Atari 2600 itself. I seem to recall Atari trying to sue them for making (copying the Atari 2600) too, but I forget all the details. An Intellivision adapter would be the same thing. Since the Inty is a 16bit CPU and nothing even remotely is similar between the CV and Inty you might as well just set an Inty on top of your CV and call it a module...

 

Just a note though....

 

The CV uses a z-80 processor so using the expansion port and some more hardware you could make a system capable of running CP/M..

Edited October 20, 2015 by juice2839

[NIAD]

The Atari adapter for the Colecovision is a piece of work. It really is just an Atari 2600 in a different case. Pretty much none of the CV hardware is used at all when it's plugged in. The CV is just a pass through to the RF converter.

The E.M. #1 Atari Adapter alsoi, and obviously, uses the power from the ColecoVision as well as the RF output that you mentioned.

 

 

The CV uses a z-80 processor so using the expansion port and some more hardware you could make a system capable of running CP/M..

This was already done by Coleco back in 1983, it is called the ADAM Computer in either the Expansion Module #3 or Stand-Alone variety. Coleco also released CP/M 2.2 & Assembler for the ADAM which made it possible to run thousands of CP/M compatible programs, but using this alternate O.S. from the Digital Data Drive(s) was very tedious (disk drives were a must) because the O.S. is very I/O dependent and large RamDrives as well as Hard Drives were not developed by 3rd party companies until the late 1980's. Another drawback was the ADAM's 32 column display seeing that a moving window of 80 columns or using a screenchop program could become very frustrating... well, at least until 80 column units were released for the ADAM in 1985.

 

If you delve into it using an emulator such as Virtual ADAM, also check out the vastly improved CP/M alternative called T-DOS.

[+5-11under]

Someone converted an expansion module into a standalone unit, and needed to add a clock, because the expansion module doesn't have one... from what I recall.

[juice2839]

The E.M. #1 Atari Adapter alsoi, and obviously, uses the power from the ColecoVision as well as the RF output that you mentioned.

 

 

This was already done by Coleco back in 1983, it is called the ADAM Computer in either the Expansion Module #3 or Stand-Alone variety. Coleco also released CP/M 2.2 & Assembler for the ADAM which made it possible to run thousands of CP/M compatible programs, but using this alternate O.S. from the Digital Data Drive(s) was very tedious (disk drives were a must) because the O.S. is very I/O dependent and large RamDrives as well as Hard Drives were not developed by 3rd party companies until the late 1980's. Another drawback was the ADAM's 32 column display seeing that a moving window of 80 columns or using a screenchop program could become very frustrating... well, at least until 80 column units were released for the ADAM in 1985.

 

If you delve into it using an emulator such as Virtual ADAM, also check out the vastly improved CP/M alternative called T-DOS.

 

Expensive stuff in the 80's but trivial now. I have to admit the colecovisions expansion port is probably the best I have seen for accessing all the bus signals, but it goes over the top and lets you disable the address decoding in the CV and gives you almost total control of the hardware on board.. You could really turn the colecovision into anything that ran a Z-80 processor. I could make a Pacman arcade game with it. I mean I could actually make it run the real Pacman code pretty easily with some extra hardware on the expansion bus. It would be really really easy to turn it into a timex sinclair or a Trs-80 model I .................Oh the possibilities.

[+5-11under]

I thought of several expansion modules that could be attached to the CV, but never built anything. Certainly some of them would be fun or interesting, but in the end, I decided... why? That's just me, though. Like I said, there's some interesting possibilities.

[juice2839]

I thought of several expansion modules that could be attached to the CV, but never built anything. Certainly some of them would be fun or interesting, but in the end, I decided... why? That's just me, though. Like I said, there's some interesting possibilities.

 

Right. You can just buy all those old systems and computers fairly cheap now so why bother making adapters... Just fun to think about for a second. This winter I may make a whole coleco pcb about 1/2 the size or smaller from the original with smt parts and a socket for the TMS. So you can have a daughter pcb that plugs into the TMS socket with ram built on it or plug a f18a into it. If I can make it small enough you might even be able to make a hand held CV with a built in screen. Especially if you used a f18a and a 5" lcd vga display. Be kinda of a neat project.

[+FujiSkunk]

It's probably already been sufficiently answered, but just to be thorough...

I've been thinking lately about how Coleco designed their Atari adapter for the Colecovision. Since the Coleco has a 30 pin cartridge slot and the Atari had 24 pins, certainly they couldn't reuse the cartridge slot and had to have another one, but couldn't they have done something like Sega did with the Genesis Power base converter? Or like those retrobit converters for the SNES?

The Genesis Power Base converter is a different scenario. All of the hardware needed to run Master System games is already inside the Genesis console. It's a bit like the Atari 7800 in that respect. All the Power Base converter really does is make the cartridge port suitable for plugging in a Master System game. The console does the rest.

The Retrobit Genesis adapter for the SNES works similarly to how Atari's 2600 adapter for the 5200 works. Basically, Retrobit crammed an entire Genesis-compatible console crammed into a SNES cartridge. Both adapters use the underlying hardware to draw power and for some basic tasks, but most of the grunt work is handled by the adapter itself. In fact, the Retrobit adapter can't even feed its audio and video back through the SNES; you have to have a separate cable plugged directly into the adapter for that.

Would it possible to design an Atari converter that clips on the cartridge slot rather than the expansion slot and simply reuses the colecovisions controller ports? Maybe using something like the chip in the Atari Flashback 2? I know even the NES can do it since the retrovision gameboy adapter exists.

Maybe, but I'm guessing not. The 5200's 2600 adapter can use the cartridge port because the 5200 allows for audio and video to be sourced from the cartridge port. The ColecoVision's expansion port has this same ability, but the cartridge port might not. If not, then any adapter that uses the cartridge port would also need its own A/V outputs, just like the Genesis adapter for the SNES. At that point you may as well just design and build a smaller 2600 adapter to plug into the expansion port.

 

All of this neglects to mention the challenge with controllers, which others have already covered.