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5-11under

ColecoVision 1.2 - replacement PCB, added features

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Okay, the time has finally come. I'm going to make a new drop-in replacement PCB for the ColecoVision. Other form factors such as portables could be made in the future (but not right now). This is still a ColecoVision; I've been calling it a CV-1.2. It's a regular CV with some improvements; it's not the next generation CV-2 with more graphics modes, audio channels, bits, etc.

Here's the feature list of the CV-1.2:

  • Component (YPbPr) video output - both RCAs and 1/8" jack provided
  • Composite video output - both RCA and 1/8" jack provided - I don't really want to add this, but I'm guessing it's pretty much required, right?
  • VGA (pure analog, not an F18A type solution) video output - I'm not sure if this will work yet, so don't count on it
  • Audio output - both RCAs and 1/8" jack provided - mono of course, but two outputs available for stereo TVs
  • 24K RAM - for Adam conversions such as Super Zaxxon and Dragon's Lair
  • Static RAM for VDP - instead of DRAM
  • Extra controller ports - to use 2 button Atari 7800 (or 2600), Sega SMS, Sega Genesis controllers
  • Extra keypad support - could be added on the top of the CV console (useful if using Atari or Sega controllers)
  • Easily replaceable controller input chips
  • Single +5V input - either via standard CV power supply or smaller/efficient adapter
  • Internally created -5V and +12V output - Atari Expansion Module support
  • Output voltage for Roller controller - via standard CV power jack
  • Power on LED - multicolour
  • Alternate BIOSes - standard 10s delay, 3s delay, 10s/fire delay, etc.
  • Pause button - capacitive so it's hidden (hopefully), also turns on light, and turns off audio output
  • Built-in 31 game multi-"cart" - activated if no game is inserted
  • Expansion module circuitry remains - for SGM and Atari Expansion Module support
  • All new parts used - except for VDP and audio, which use NOS (new old stock) parts
  • Fits in standard CV case - existing holes in back of CV will likely line up with A/V output and power input

The features listed are meant to improve the quality of play of the system, for instance by adding proper video outputs, extra controller/keypad inputs, pause switch, and the simple multicart. The reliability of the system is improved by using static RAM for the VDP, allowing a standard 5V power adapter to be used (this should also make the power switch less finicky), making the controller input chips easy to replace, and using brand new parts.

If there are features missing that you think should be added, please feel free to discuss.

Unfortunately, this isn't going to be cheap. As usual, I'll do my best to make it as affordable as possible. I'd also like to make a bare-bones version that is still reliable, but doesn't provide some of the extras such as multicart, extra controller inputs, etc.

As mentioned, a 31 game multi-"cart" is included. I don't want to add games that I don't have permission to include, so if there's anyone who has games or utilities that could be added, whether it be full or demo versions, please contact me. I'm not sure what kind of compensation could be given, but that's all up for discussion, I guess.

Edited by 5-11under
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Big project

 

If going to drop into standard CV, perhaps use DIN connector to provide multiple A/V options in single smaller connector in same spot as RF hole. The multi-AV cable from Neo Geo Omega is kind of neat.

 

For the extra controller ports, how would those be used. Is the idea to have a built in Y-cable?

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No HDMI support?

 

No HDMI support. You could buy a cheap converter from eBay and install it. However, I've found that sometimes you can't bring the video back to 4:3 format. Depends on the converter and the TV, I suppose.

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No HDMI support. You could buy a cheap converter from eBay and install it. However, I've found that sometimes you can't bring the video back to 4:3 format. Depends on the converter and the TV, I suppose.

No big deal actually, was only wondering

I don't really care about since I prefer to use CRT for old school systems

 

.....thinking about it..... i don't really play any modern stuff, so I guess I don't care about HDMI at all :P

 

I even prefer VHS over DVD/Blue Ray

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Probably already replied to this topic.

 

I'd just like to reinforce RCA jacks are very, very important to me.

 

I'm not sure if the board can be powered by USB but that would be handy. I like using USB battery packs to power stuff off-the-grid.

 

Instead of 310000-in-1 games I wish that space could be used for uploading games of your choice. I'd love to use this for developing new homebrew games!

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Big project

 

If going to drop into standard CV, perhaps use DIN connector to provide multiple A/V options in single smaller connector in same spot as RF hole. The multi-AV cable from Neo Geo Omega is kind of neat.

 

For the extra controller ports, how would those be used. Is the idea to have a built in Y-cable?

 

I'll consider a cable. It's ideal if I can find an inexpensive pre-built one. I'll investigate the Neo Geo one... it would save on connectors, that's for sure.

 

The extra controller ports allow use of Atari and Genesis controllers. Normally you can only use a single-button controller meant for another console. This will allow the second button to be mapped properly, so that more games are compatible. The main ports would remain the same. The extra ports would be used for Atari/Sega 2 button controllers. I may add an extra regular port (or combine it with the Atari/Sega port) to act as a "Y" cable. I think that all made sense. ;)

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So is this going to be a NA only thing or can use Europeans join in the fun too?? Either way I'm interested :) Any estimate on price too??

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Probably already replied to this topic.

 

I'd just like to reinforce RCA jacks are very, very important to me.

 

I'm not sure if the board can be powered by USB but that would be handy. I like using USB battery packs to power stuff off-the-grid.

 

Instead of 310000-in-1 games I wish that space could be used for uploading games of your choice. I'd love to use this for developing new homebrew games!

 

Noted regarding the RCAs.

Regarding USB power... great idea!

It's not 310000, it's 31!... but I guess you knew that ;) It's not uploadable, because that would add to the engineering and the cost too much. You'll have to stick with the USB or SD multicart from Atarimax at this point.

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So is this going to be a NA only thing or can use Europeans join in the fun too?? Either way I'm interested :) Any estimate on price too??

 

NTSC/PAL: good question. I've tried to not think of that. It might not be too bad to add PAL. We'll see.

 

Sorry, no price estimate yet. Time will tell.

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I'm very interested in this! Count me in! The most interesting feature for me is the component/composite video output. Removing the BIOS artificial delay is also a great idea.

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NTSC/PAL: good question. I've tried to not think of that. It might not be too bad to add PAL. We'll see.

 

Sorry, no price estimate yet. Time will tell.

Best not forget the French & their wacky SECAM system too ;) Look forward to seeing this come to fruition. I'm sure ill be in for at least one :)

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If you're using NOS VDP chips then don't you run into the same issue as your component video mod, i.e. that you'll need to have user adjustable pots to "tune" the component output. I believe this is necessary due to the variability (low tolerance) on colour in the TMS9928.

 

You need to be careful with those alternative BIOS options, for instance one of the fire/skip BIOS files does not play nicely with Sewer Sam (http://atariage.com/forums/topic/196349-sewer-sam-and-bluemsx/).

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If you're using NOS VDP chips then don't you run into the same issue as your component video mod, i.e. that you'll need to have user adjustable pots to "tune" the component output. I believe this is necessary due to the variability (low tolerance) on colour in the TMS9928.

 

You need to be careful with those alternative BIOS options, for instance one of the fire/skip BIOS files does not play nicely with Sewer Sam (http://atariage.com/forums/topic/196349-sewer-sam-and-bluemsx/).

 

It's untested so far, but I think I have a solution for the component video. Hopefully.

 

Noted regarding the BIOS. I think my favourite is the 3 second delay.

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If you're using NOS VDP chips then don't you run into the same issue as your component video mod, i.e. that you'll need to have user adjustable pots to "tune" the component output. I believe this is necessary due to the variability (low tolerance) on colour in the TMS9928.

 

You need to be careful with those alternative BIOS options, for instance one of the fire/skip BIOS files does not play nicely with Sewer Sam (http://atariage.com/forums/topic/196349-sewer-sam-and-bluemsx/).

 

For the BIOS hacking, you need to be careful to not move anything else out of their original address range. Lots of games, for example, reference the char patterns for letters/numbers directly. Even Coleco made games are guilty of that (though they usually use the pointers near the start of the BIOS code). Some also use subroutines that weren't mapped in the "jump table", like the ones for flipping and rotating patterns.

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Okay, the time has finally come. I'm going to make a new drop-in replacement PCB for the ColecoVision. Other form factors such as portables could be made in the future (but not right now). This is still a ColecoVision; I've been calling it a CV-1.2. It's a regular CV with some improvements; it's not the next generation CV-2 with more graphics modes, audio channels, bits, etc.

This sounds like a great project, but I do have questions and comments:

 

- Component (YPbPr) video output - both RCAs and 1/8" jack provided

- Composite video output - both RCA and 1/8" jack provided - I don't really want to add this, but I'm guessing it's pretty much required, right?

So you would offer a choice between these configurations, or would they all be included on the same board?

 

 

- 24K RAM - for Adam conversions such as Super Zaxxon and Dragon's Lair

You'll have to be careful how you implement this. In particular, the ADAM games on cartridge perform some specific tests to detect the ADAM and the SGM...

 

 

- Extra controller ports - to use 2 button Atari 7800 (or 2600), Sega SMS, Sega Genesis controllers

Where would these extra ports be located on the console?

 

 

- Extra keypad support - could be added on the top of the CV console (useful if using Atari or Sega controllers)

Um... You want to put the extra keypad close to the cartridge port, I suppose? I'm not sure I'm confortable with that idea...

 

 

- Single +5V input - either via standard CV power supply or smaller/efficient adapter

- Internally created -5V and +12V output - Atari Expansion Module support

- Output voltage for Roller controller - via standard CV power jack

What is easiest to find in places like Radio-Shack? A 5V or 12V generic adaptor?

 

 

Power on LED - multicolour

Are you talking about a LED which is part of the power switch, or separate? In any case, I suppose you'll want to use another kind of power switch, right?

 

Alternate BIOSes - standard 10s delay, 3s delay, 10s/fire delay, etc.

So you will let the buyer choose which BIOS he/she wants?

 

 

Pause button - capacitive so it's hidden (hopefully), also turns on light, and turns off audio output

What does "capacitive" mean, exactly?

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...

 

Any other questions? ;) I'm lumping this all together...

 

Component and Composite would both be available at the same time. If they don't play nice with each other, there would a little switch or jumper on the board (or side of board?) and you could switch between them.

 

For the 24K versus 1K RAM, the Super Zaxxon and Dragon's Lair will work fine on this unit, with or without the SGM attached. The bigger question is whether any games abuse the fact that the 1K RAM is mirrored. If yes, I'll need a way to switch between 1K mirrored and 24K non-mirrored, or just stick with 1K.

 

The extra controller ports would likely be on the right of the console, unless anyone has a better idea.

 

The extra keypad could go wherever you wanted it... but I'm designing it so that yes, they'd be pretty much behind the cartridge port. It's pretty much the only flat area. It's meant to be used to start games when you're using a 7800 controller, for instance. It's not meant for games such as Mouse Trap that extensively use the keypad... although it could be used for that if someone really wanted to. You wouldn't need to install a keypad if you didn't want to, of course.

 

It would use an easy-to-find 5V adapter (2.1mm/5.0mm barrel connector, if I recall correctly), or hopefully a USB (type B) power jack. Both jacks would be installed.

 

The LED would likely be separate from the switch. The switch is still to be determined. If it's not a direct replacement, I'd like to have an option to install a standard one. Hopefully without the old DRAM chips for the VDP, it would be fine to use the old switch.

 

The BIOS will be selectable between up to about 4 versions via jumper switches on the board.

 

Capacitive pause switch: if it works properly, you would just touch a certain part of the outer case to pause a game (touch again to continue). No real "switch" required, so no case modification required to take advantage of this feature. If it works, of course. I'll make sure it works with a proper switch, too, to open up options.

Edited by 5-11under

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This sounds like a really cool project.

 

Is it completely out of scope to sell these in a case, rather than as a pop-in replacement? My reasoning for this is I worry what will happen to the original CV boards that are being replaced, specifically those that are still fully functional. It would be a shame for original boards to just go to waste.

 

Could the replaced boards be re-used for other projects? Maybe the CV2?

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This sounds like a really cool project.

 

Is it completely out of scope to sell these in a case, rather than as a pop-in replacement? My reasoning for this is I worry what will happen to the original CV boards that are being replaced, specifically those that are still fully functional. It would be a shame for original boards to just go to waste.

 

Could the replaced boards be re-used for other projects? Maybe the CV2?

Having a CV system mold is somthing I have in mind

I do want a transparent shell for my CV. :D

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Any other questions? ;) I'm lumping this all together...

 

Component and Composite would both be available at the same time. If they don't play nice with each other, there would a little switch or jumper on the board (or side of board?) and you could switch between them.

I could switch between them? You mean I would have to unscrew and open up the console's casing to access the dip switch or jumper?

 

 

For the 24K versus 1K RAM, the Super Zaxxon and Dragon's Lair will work fine on this unit, with or without the SGM attached. The bigger question is whether any games abuse the fact that the 1K RAM is mirrored. If yes, I'll need a way to switch between 1K mirrored and 24K non-mirrored, or just stick with 1K.

I believe Super Cobra "abuses the mirroring", as you say. :)

 

 

The extra controller ports would likely be on the right of the console, unless anyone has a better idea.

 

The extra keypad could go wherever you wanted it... but I'm designing it so that yes, they'd be pretty much behind the cartridge port. It's pretty much the only flat area. It's meant to be used to start games when you're using a 7800 controller, for instance. It's not meant for games such as Mouse Trap that extensively use the keypad... although it could be used for that if someone really wanted to. You wouldn't need to install a keypad if you didn't want to, of course.

That's a lot of holes to drill/cut into the console...

 

The LED would likely be separate from the switch. The switch is still to be determined. If it's not a direct replacement, I'd like to have an option to install a standard one. Hopefully without the old DRAM chips for the VDP, it would be fine to use the old switch.

No it would not, my friend. Anything to get rid of that stupid slide switch... :ponder: Also, having your own "more-or-less custom" switch would make the CV 1.2 instantly recognizable on eBay.

 

 

The BIOS will be selectable between up to about 4 versions via jumper switches on the board.

Hmm... Another reason to open up the case... :|

 

 

Capacitive pause switch: if it works properly, you would just touch a certain part of the outer case to pause a game (touch again to continue). No real "switch" required, so no case modification required to take advantage of this feature. If it works, of course. I'll make sure it works with a proper switch, too, to open up options.

It's an interesting idea, I guess. But how about something simpler: Tap the reset button to pause, tap again to unpause, and hold down the reset button for 3 full seconds to initiate a true console reset. I don't know if such a solution is doable, of course, but it's certainly desirable. :)

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