Sega or Nintendo to Colecovision Mod?

[thegamezmaster]

Is there a guide as how to make a Sega or Nintendo joystick with two button capability to use on a CV? Checked the web with no luck. And doing something like this from scratch is way beyond my ability. Thanks for any help with this!

[Hannacek]

If you check youtube Willie from Arcadeusa has a few videos showing how to mod a genesis controller. Modding an nes controller is more difficult, but the principal is the same. And Atariage has an article on Modding an nes controller for Atari 7800.

[thegamezmaster]

If you check youtube Willie from Arcadeusa has a few videos showing how to mod a genesis controller. Modding an nes controller is more difficult, but the principal is the same. And Atariage has an article on Modding an nes controller for Atari 7800.

Thanks have seen those but was looking for something about modding joysticks. Thanks!

[jjh76]

Don't know about modding, but there is the Champ keypad which is basically a number pad with a db9 connector that can let you use atari style joysticks with the Colecovision.

 

https://atariage.com/forums/topic/266820-champ-keypad-controller-adapter/

[Andromeda Stardust]

Swami had some success using one of my 7800 controllers with a Y-adapter.

http://atariage.com/forums/topic/259503-handmade-cigar-box-arcade-controllers-for-sale/?p=3793368

[thegamezmaster]

Thanks for all the help and replies!

[thegamezmaster]

Can anyone help with a guide to do this with either a SMS Joystick or a NES Advantage or a sega genesis 3 button arcade stick please. Thanks for any help!

[Swami]

I've used a SMS Master controller joystick and gotten both buttons to work. It requires using an adapter, but I have several and I would have to go back and check which one(s) it was. At this point, though, having this setup deactivated the keypad plugged into the second port that you use to start the game and choose difficulty. You end up having to unplug the sega controller to get the keypad to work and then plug it back in. This is a bad thing to do for your colecovision, as Yurkie says it can damage the controller chips in your console:

 

http://atariage.com/forums/topic/249404-modifying-a-sega-genesis-controller-for-use-on-colecovision/?p=3450018

 

This problem does not occur with a 7800 fightstick type controller setup I've tried. It does not require and adapter, although it may require a y-splitter. I have to go back and check tonight. It is kind of an incomplete study, but I should be able to sort it out and maybe I'll write it down this time.

[Rey]

Can anyone help with a guide to do this with either a SMS Joystick or a NES Advantage or a sega genesis 3 button arcade stick please. Thanks for any help!

I did my sega genesis controller but not the arcade stick. All my stuff has been put away for awhile now and don't know when I can get to them. I did find a pic I posted when I did the SMS controller.

 

http://atariage.com/forums/topic/222610-happy-friday-colecovision-fans/?p=3024411

[Swami]

Can anyone help with a guide to do this with either a SMS Joystick or a NES Advantage or a sega genesis 3 button arcade stick please. Thanks for any help!

So trying things out at home tonight:

If you use an SMS master controller inline with a sega SMS rapid fire adapter, you can set it so both buttons work on games like Cosmic Avenger. You cannot use both buttons at the same time and you cannot use the keypad of a standard CV controller plugged into the second controller port (or the other port of a y-splitter cable), although the joystick and both fire button work normally (and at the same time) on the simultaneously connected standards controller. You can get the interesting effect of one button to alternate between rapid fire shooting and bombing is Cosmic Avenger (by setting the sega rapid fire adapter correctly it will shoot (button B) on rapid fire, pressing button A will bomb but omit a single shot, holding button A will rapid-fire bombs while not firing, allowing you controlled fire when you need it with bombs rapid fire dropping in the meanwhile, or vice versa is also possible.

 

The biggest problem, of course, is not being able to have the keypad work while the rapid fire adapter is attached. The keypad will work with a 2600 or 7800 controller attached, although again only one button at a time will work on the 7800 controller. Still, having a custom 7800 two-button stick is still very nice to use for many games; Just some games will still require a CV controller. Apparently, the closest thing to a non-sucky CV controller is the CV super-game controller. Back to the 7800/SMS controllers, a simple mod would involve wiring the CV standard controller button leads to the buttons of the 7800 arcade box or SMS controller, which would require both controllers to be plugged in and wired to each other via the button A and B leads, although they do not have to be close to each other. If someone is using an SMS or Genesis joystick, it does not sound like they would be planning to have the keypad in hand anyway.However, under such a situation, the rapid fire adapter would not be used and the keypad would work with either the SMS master controller or 7800 arcade box plugged in.

 

By the way, having the Seagull 78 adapter plugged into player 1 port will also block the CV controller keypad in either the player 2 port or the other y-adapter plug. However, this adapter leads to erratic firing/bombing behavior.

 

The only thing I haven't tried is trying all the above configurations with a swap between player 1 and player 2 ports on the CV.

 

Finally, people have mentioned the Champ keypad adapter here and there, which can use both buttons of an attached joystick, but I don't know if either the 2-working-fire-button model or the ones modded to work with 2-buttons allow for both button A and B to be used at the same time.

[Swami]

Swami had some success using one of my 7800 controllers with a Y-adapter.

http://atariage.com/forums/topic/259503-handmade-cigar-box-arcade-controllers-for-sale/?p=3793368

 

 

Can anyone help with a guide to do this with either a SMS Joystick or a NES Advantage or a sega genesis 3 button arcade stick please. Thanks for any help!

Also, with a custom arcade stick box, like Kosmic Stardust is mentioning, one could get such a box, fit a standard CV controller to it and wire the button A and B leads to the box's fire buttons to have an arcade stick box with simultaneously firing buttons and a keypad.

[Andromeda Stardust]

Also, with a custom arcade stick box, like Kosmic Stardust is mentioning, one could get such a box, fit a standard CV controller to it and wire the button A and B leads to the box's fire buttons to have an arcade stick box with simultaneously firing buttons and a keypad.

Or if the 7800 controller schematic works as you say, I could add a male DB-9 as passthrough for the keypad.

 

A couple of questions to you regarding compatibility:

 

Do both 7800 buttons work simultaneously, or one at a time? I won't put a male Dsub pass-through on my boxes for Coleco use unless they do not interfere with operation of the keypad or each other. I don't have space or budget for another console at this time, so getting a Colecovision of my own is off the cards for me.

 

Secondly, while the schematic is fairly simple. Real CV controller seems to have two ground planes, with the joystick and left fire connected to one plane (pin , and the keypad and right fire to the other (I forget the pinout offhand). The CV controller also appears to have a diode matrix which assigns a 4-bit value to each key on the keypad, sent through pins 1-4 from the second ground plane, right fire sent through pin 6 from the second ground plane, and also isolates the joystick and left fire to the primary ground plane through a diode network.

 

Without this diode network in place, crosstalk is possible between the two ground planes. I assume the primary and secondary plane are alternately pulled low by the console CPU, with the console making a separate read on the inputs from both planes allowing simultaneous joystick, fire, and keypad reads without interference. Herein lies my theory about why both buttons fail to operate in tandem when using a 7800 controlker. A standard 2600 controller works as left fire + joystick because it establishes contact between the primary ground plane and the inputs. A 7800 controller switches pin 6 to pins 9 and/or5 as well as holds these inputs low through the resitors. There are no diodes in a 7800 controller that I know of, and my 7800 sticks certainly don't utilize them. Pressing both buttons on a 7800 stick bridges pins 5, 6, and 9 together, with about 310 ohms total resistance to ground. My sticks I sub in a pair of 560 ohm resistors because 620s were not available, so this value is reduced to 280 ohms.

 

Anyway without diodes isolating all inputs from the two ground planes, it is possible for the two planes to have bus conflict with each other when the outputs are bridged together. This would lead to malfunction. So if I made a CV compatible joystick, these isolation diodes would need to be present on the joystick and both buttons, along with a male Dsub to pass through for the original keyboard matrix. It would likely work on a 2600 as well with the primary fire, but the inputs would be .6v instead of 0. Most logic chips expect below .8v for tolerance so it should work. Bigger issue here is I test everything on original hardware before shipping, so if I built a Coleco compatible controller, I would need a Coleco system to test it with.

 

Unless someone literally sends me a Coleco along with a test cart, I won't be building controllers specifically for it. Otherwise I would just wait for Edladdin to release his upcoming Coleco stick. He's making an adapter with keypad built in and 4 Dsubs for 7800/SMS/Coleco/Flashback, but it will cost $99, so at that price point one may as well pay a bit extra and buy the full CV joystick from him.

 

Hopefully no one is disappointed that I cannot offer my services at this time to make CV-compatible controllers. I can do 2600, 7800, SMS+ (2600 "extra button" compatible), 3-button Genesis, and NES. Genesis and Turbografx both use a 74LS157 and NES uses a CD4021, both of which are still available from parts distributors. I've got a tube of CD4021s somewhere. SNES uses two CD4021s and Genesis 6-button is a custom ASIC, which means I would need to buy a cheap Yobo controller and "pad hack" it. Not really planning on doing "fight sticks" for 16-bit gen and up, as it's a ton of work to build and there's plenty of commercial products out there.

 

TL;DR: I'm not doing CV controllers as I lack the OEM equipment to test them. Wait for Edladdin to announce something CV related.

[Swami]

Or if the 7800 controller schematic works as you say, I could add a male DB-9 as passthrough for the keypad.

 

A couple of questions to you regarding compatibility:

 

Do both 7800 buttons work simultaneously, or one at a time? I won't put a male Dsub pass-through on my boxes for Coleco use unless they do not interfere with operation of the keypad or each other. I don't have space or budget for another console at this time, so getting a Colecovision of my own is off the cards for me.

 

Secondly, while the schematic is fairly simple. Real CV controller seems to have two ground planes, with the joystick and left fire connected to one plane (pin , and the keypad and right fire to the other (I forget the pinout offhand). The CV controller also appears to have a diode matrix which assigns a 4-bit value to each key on the keypad, sent through pins 1-4 from the second ground plane, right fire sent through pin 6 from the second ground plane, and also isolates the joystick and left fire to the primary ground plane through a diode network.

 

Without this diode network in place, crosstalk is possible between the two ground planes. I assume the primary and secondary plane are alternately pulled low by the console CPU, with the console making a separate read on the inputs from both planes allowing simultaneous joystick, fire, and keypad reads without interference. Herein lies my theory about why both buttons fail to operate in tandem when using a 7800 controlker. A standard 2600 controller works as left fire + joystick because it establishes contact between the primary ground plane and the inputs. A 7800 controller switches pin 6 to pins 9 and/or5 as well as holds these inputs low through the resitors. There are no diodes in a 7800 controller that I know of, and my 7800 sticks certainly don't utilize them. Pressing both buttons on a 7800 stick bridges pins 5, 6, and 9 together, with about 310 ohms total resistance to ground. My sticks I sub in a pair of 560 ohm resistors because 620s were not available, so this value is reduced to 280 ohms.

 

Anyway without diodes isolating all inputs from the two ground planes, it is possible for the two planes to have bus conflict with each other when the outputs are bridged together. This would lead to malfunction. So if I made a CV compatible joystick, these isolation diodes would need to be present on the joystick and both buttons, along with a male Dsub to pass through for the original keyboard matrix. It would likely work on a 2600 as well with the primary fire, but the inputs would be .6v instead of 0. Most logic chips expect below .8v for tolerance so it should work. Bigger issue here is I test everything on original hardware before shipping, so if I built a Coleco compatible controller, I would need a Coleco system to test it with.

 

Unless someone literally sends me a Coleco along with a test cart, I won't be building controllers specifically for it. Otherwise I would just wait for Edladdin to release his upcoming Coleco stick. He's making an adapter with keypad built in and 4 Dsubs for 7800/SMS/Coleco/Flashback, but it will cost $99, so at that price point one may as well pay a bit extra and buy the full CV joystick from him.

 

Hopefully no one is disappointed that I cannot offer my services at this time to make CV-compatible controllers. I can do 2600, 7800, SMS+ (2600 "extra button" compatible), 3-button Genesis, and NES. Genesis and Turbografx both use a 74LS157 and NES uses a CD4021, both of which are still available from parts distributors. I've got a tube of CD4021s somewhere. SNES uses two CD4021s and Genesis 6-button is a custom ASIC, which means I would need to buy a cheap Yobo controller and "pad hack" it. Not really planning on doing "fight sticks" for 16-bit gen and up, as it's a ton of work to build and there's plenty of commercial products out there.

 

TL;DR: I'm not doing CV controllers as I lack the OEM equipment to test them. Wait for Edladdin to announce something CV related.

1. I used the standard 7800 controller I picked up shortly before the arcade box during yesterday's testing. Only one button at a time worked on this 7800 controller, while both buttons worked at the same time on the standard CV controller that was simultaneously connected. Otherwise the 7800 + CV controller setup works flawlessly and has no interference with the CV keypad. I can try out your model tonight to see if the resistors or something else make a difference. I know it works at least as flawlessly as the standard 7800 controller and CV controller together.

 

2. I agree the matrix system used by the CV can make things complicated for adapting. I know Edladdin has faced puzzling obstacles with Colecovision compatibility for the multi-platform arcade controller they were originally planning. It sounds like they have abaondoned it in favor of a more dedicated CV controller. However, what I was suggesting was limited to an after-market DIY mod for the OP to test himself, which was to attach wires to each surface of the two push-button contacts of the standard CV controller button A and button B and then attach the other ends to the push contacts for buttons A and B on a DB9 controller of choice. I think doing this with a 7800 arcade box like yours might be easiest for the OP, but it should also be possible with various Sega joystick controllers. Although you would always be tethered to the standard CV controller. Generally, the joystick and one button of a DB9 controller will work almost universally with the Colecovision, the second button and simultaneous button operation could be difficult, and are are rare, without exactly copying the CV controller schematic, so it seems like it may be worth the simplification to take a DB9 controller of choice and use a CV board as a button A & B surrogate and the de facto keyboard. However, this would require having decent soldering equipment and the knowledge to use it, versus just slapping adapters and controllers together like I have tried. I usually try to find the lowest tech solution first as it can be used by the most people. Edladdin had some issue with fire button cross-talk for some games such as defender on some CV consoles, where smart bombs were going off when pushing button A to fire. Grips03 said he quit because he only sold like three controllers, possibly because interest hadn't swelled yet, customization wasn't offered, or the $175 cost to make it put the price point too high.

 

Personally, I don't care for controllers with the buttons on the right, so what I've seen from Edladdin and Grips03 for the CV hasn't appealed to me. I would rather use the super action controller.

[Swami]

Or if the 7800 controller schematic works as you say, I could add a male DB-9 as passthrough for the keypad.

 

A couple of questions to you regarding compatibility:

 

Do both 7800 buttons work simultaneously, or one at a time? I won't put a male Dsub pass-through on my boxes for Coleco use unless they do not interfere with operation of the keypad or each other. I don't have space or budget for another console at this time, so getting a Colecovision of my own is off the cards for me.

 

Secondly, while the schematic is fairly simple. Real CV controller seems to have two ground planes, with the joystick and left fire connected to one plane (pin , and the keypad and right fire to the other (I forget the pinout offhand). The CV controller also appears to have a diode matrix which assigns a 4-bit value to each key on the keypad, sent through pins 1-4 from the second ground plane, right fire sent through pin 6 from the second ground plane, and also isolates the joystick and left fire to the primary ground plane through a diode network.

 

Without this diode network in place, crosstalk is possible between the two ground planes. I assume the primary and secondary plane are alternately pulled low by the console CPU, with the console making a separate read on the inputs from both planes allowing simultaneous joystick, fire, and keypad reads without interference. Herein lies my theory about why both buttons fail to operate in tandem when using a 7800 controlker. A standard 2600 controller works as left fire + joystick because it establishes contact between the primary ground plane and the inputs. A 7800 controller switches pin 6 to pins 9 and/or5 as well as holds these inputs low through the resitors. There are no diodes in a 7800 controller that I know of, and my 7800 sticks certainly don't utilize them. Pressing both buttons on a 7800 stick bridges pins 5, 6, and 9 together, with about 310 ohms total resistance to ground. My sticks I sub in a pair of 560 ohm resistors because 620s were not available, so this value is reduced to 280 ohms.

 

Anyway without diodes isolating all inputs from the two ground planes, it is possible for the two planes to have bus conflict with each other when the outputs are bridged together. This would lead to malfunction. So if I made a CV compatible joystick, these isolation diodes would need to be present on the joystick and both buttons, along with a male Dsub to pass through for the original keyboard matrix. It would likely work on a 2600 as well with the primary fire, but the inputs would be .6v instead of 0. Most logic chips expect below .8v for tolerance so it should work. Bigger issue here is I test everything on original hardware before shipping, so if I built a Coleco compatible controller, I would need a Coleco system to test it with.

 

Unless someone literally sends me a Coleco along with a test cart, I won't be building controllers specifically for it. Otherwise I would just wait for Edladdin to release his upcoming Coleco stick. He's making an adapter with keypad built in and 4 Dsubs for 7800/SMS/Coleco/Flashback, but it will cost $99, so at that price point one may as well pay a bit extra and buy the full CV joystick from him.

 

Hopefully no one is disappointed that I cannot offer my services at this time to make CV-compatible controllers. I can do 2600, 7800, SMS+ (2600 "extra button" compatible), 3-button Genesis, and NES. Genesis and Turbografx both use a 74LS157 and NES uses a CD4021, both of which are still available from parts distributors. I've got a tube of CD4021s somewhere. SNES uses two CD4021s and Genesis 6-button is a custom ASIC, which means I would need to buy a cheap Yobo controller and "pad hack" it. Not really planning on doing "fight sticks" for 16-bit gen and up, as it's a ton of work to build and there's plenty of commercial products out there.

 

TL;DR: I'm not doing CV controllers as I lack the OEM equipment to test them. Wait for Edladdin to announce something CV related.

BTW, I never had the need to push both buttons at the same time in my past game play for the CV. I just ran across this issue while doing a search inspired by the OP. Always something new ... just ask Edladdin and Harmony.

[Swami]

Or if the 7800 controller schematic works as you say, I could add a male DB-9 as passthrough for the keypad.

 

A couple of questions to you regarding compatibility:

 

Do both 7800 buttons work simultaneously, or one at a time? I won't put a male Dsub pass-through on my boxes for Coleco use unless they do not interfere with operation of the keypad or each other. I don't have space or budget for another console at this time, so getting a Colecovision of my own is off the cards for me.

 

Secondly, while the schematic is fairly simple. Real CV controller seems to have two ground planes, with the joystick and left fire connected to one plane (pin , and the keypad and right fire to the other (I forget the pinout offhand). The CV controller also appears to have a diode matrix which assigns a 4-bit value to each key on the keypad, sent through pins 1-4 from the second ground plane, right fire sent through pin 6 from the second ground plane, and also isolates the joystick and left fire to the primary ground plane through a diode network.

 

Without this diode network in place, crosstalk is possible between the two ground planes. I assume the primary and secondary plane are alternately pulled low by the console CPU, with the console making a separate read on the inputs from both planes allowing simultaneous joystick, fire, and keypad reads without interference. Herein lies my theory about why both buttons fail to operate in tandem when using a 7800 controlker. A standard 2600 controller works as left fire + joystick because it establishes contact between the primary ground plane and the inputs. A 7800 controller switches pin 6 to pins 9 and/or5 as well as holds these inputs low through the resitors. There are no diodes in a 7800 controller that I know of, and my 7800 sticks certainly don't utilize them. Pressing both buttons on a 7800 stick bridges pins 5, 6, and 9 together, with about 310 ohms total resistance to ground. My sticks I sub in a pair of 560 ohm resistors because 620s were not available, so this value is reduced to 280 ohms.

 

Anyway without diodes isolating all inputs from the two ground planes, it is possible for the two planes to have bus conflict with each other when the outputs are bridged together. This would lead to malfunction. So if I made a CV compatible joystick, these isolation diodes would need to be present on the joystick and both buttons, along with a male Dsub to pass through for the original keyboard matrix. It would likely work on a 2600 as well with the primary fire, but the inputs would be .6v instead of 0. Most logic chips expect below .8v for tolerance so it should work. Bigger issue here is I test everything on original hardware before shipping, so if I built a Coleco compatible controller, I would need a Coleco system to test it with.

 

Unless someone literally sends me a Coleco along with a test cart, I won't be building controllers specifically for it. Otherwise I would just wait for Edladdin to release his upcoming Coleco stick. He's making an adapter with keypad built in and 4 Dsubs for 7800/SMS/Coleco/Flashback, but it will cost $99, so at that price point one may as well pay a bit extra and buy the full CV joystick from him.

 

Hopefully no one is disappointed that I cannot offer my services at this time to make CV-compatible controllers. I can do 2600, 7800, SMS+ (2600 "extra button" compatible), 3-button Genesis, and NES. Genesis and Turbografx both use a 74LS157 and NES uses a CD4021, both of which are still available from parts distributors. I've got a tube of CD4021s somewhere. SNES uses two CD4021s and Genesis 6-button is a custom ASIC, which means I would need to buy a cheap Yobo controller and "pad hack" it. Not really planning on doing "fight sticks" for 16-bit gen and up, as it's a ton of work to build and there's plenty of commercial products out there.

 

TL;DR: I'm not doing CV controllers as I lack the OEM equipment to test them. Wait for Edladdin to announce something CV related.

Okay, only one button at a time on the 7800 arcade box, priority to button A if both are pushed. Although joystick and keypad of simultaneously attached CV controller are not interfered with and both buttons on CV controller work at the same time. I'll have to try the CV controller to arcade button mode sometime. I believe I have located the two solder contacts for each button on the CV controller board with my multi-meter. There are 4 solder points that form an L shape under each piston mechanism of the fire buttons. The "short line" of the L points in opposite directions for button A vs B. The solder points at opposite ends of the Ls have continuity when the button is pushed in.

[Andromeda Stardust]

1. I used the standard 7800 controller I picked up shortly before the arcade box during yesterday's testing. Only one button at a time worked on this 7800 controller, while both buttons worked at the same time on the standard CV controller that was simultaneously connected. Otherwise the 7800 + CV controller setup works flawlessly and has no interference with the CV keypad. I can try out your model tonight to see if the resistors or something else make a difference. I know it works at least as flawlessly as the standard 7800 controller and CV controller together.

 

2. I agree the matrix system used by the CV can make things complicated for adapting. I know Edladdin has faced puzzling obstacles with Colecovision compatibility for the multi-platform arcade controller they were originally planning. It sounds like they have abaondoned it in favor of a more dedicated CV controller. However, what I was suggesting was limited to an after-market DIY mod for the OP to test himself, which was to attach wires to each surface of the two push-button contacts of the standard CV controller button A and button B and then attach the other ends to the push contacts for buttons A and B on a DB9 controller of choice. I think doing this with a 7800 arcade box like yours might be easiest for the OP, but it should also be possible with various Sega joystick controllers. Although you would always be tethered to the standard CV controller. Generally, the joystick and one button of a DB9 controller will work almost universally with the Colecovision, the second button and simultaneous button operation could be difficult, and are are rare, without exactly copying the CV controller schematic, so it seems like it may be worth the simplification to take a DB9 controller of choice and use a CV board as a button A & B surrogate and the de facto keyboard. However, this would require having decent soldering equipment and the knowledge to use it, versus just slapping adapters and controllers together like I have tried. I usually try to find the lowest tech solution first as it can be used by the most people. Edladdin had some issue with fire button cross-talk for some games such as defender on some CV consoles, where smart bombs were going off when pushing button A to fire. Grips03 said he quit because he only sold like three controllers, possibly because interest hadn't swelled yet, customization wasn't offered, or the $175 cost to make it put the price point too high.

 

Personally, I don't care for controllers with the buttons on the right, so what I've seen from Edladdin and Grips03 for the CV hasn't appealed to me. I would rather use the super action controller.

 

BTW, I never had the need to push both buttons at the same time in my past game play for the CV. I just ran across this issue while doing a search inspired by the OP. Always something new ... just ask Edladdin and Harmony.

 

Okay, only one button at a time on the 7800 arcade box, priority to button A if both are pushed. Although joystick and keypad of simultaneously attached CV controller are not interfered with and both buttons on CV controller work at the same time. I'll have to try the CV controller to arcade button mode sometime. I believe I have located the two solder contacts for each button on the CV controller board with my multi-meter. There are 4 solder points that form an L shape under each piston mechanism of the fire buttons. The "short line" of the L points in opposite directions for button A vs B. The solder points at opposite ends of the Ls have continuity when the button is pushed in.

The matrix system on the CV controllers...

 

IIRC, there's no direct connection to the ground and/or VCC plane on the controller port as everything is matrixed. This would make any microcontroller or converter based solution very difficult to use with a Colecovision. The microcontroller needs a power source (battery operated?) and a voltage reference in order to send back the multiplexed signals to the console as it expects them. It would have to read the state from each "ground" plane to determine if it is active (for all intents and purposes, "active" is low logic), and send forth the correct signals corresponding to expected controller inputs.

 

This in and of itself is straightforward. The Genesis and Turbographics both multiplex inputs using a 74LS157 on the select line, and such tasks as interpreting which plane is active could be handled by the micro. However microcontrollers may not be instant logic. If the Coleco is reading data on the rising edge of a pulse or the immediate following clock cycle, the "instant" response it gets from a stock controller may be sufficient, but any processing delay of a controller may result in glitching or malfunction. It is also likely that different games polled the controller with different timings, with the end result that conversion logic may operate properly in Game A but fail in Game B.

 

If this is the case, then it may not be possible to construct a logic converter to emulate the Coleco controller matrix, and may have to rely on duplication of the schematic in a custom controller. Even Atgames didn't get it right with their console, though the pinouts and schematics were public knowledge online.

[thegamezmaster]

Thanks for all the replies. But most of this is way beyond my knowledge. That's why I was looking for a written guide to do this if anyone can help. But I really do appreciate all the input, thanks!