A new low-priced "Masterplay Clone" for Sega & A2600 joystick compatibility

[Danjovic]

1 hour ago, ikonsgr said:

Actually Vcc power line is pin12 and it is not used at all! Instead, i use "pot common" (pin9) as Vcc (even for PIC supply) because pin12 doesn't seem to work right (i try to use it in the initial design but proved to be non working). And i'm pretty sure that adding an external Vcc to pin9 will mess things up!

Can you elaborare it better? I am very curious, as the trackball is powered by pin 12, and according with the service manual the console can shut down power on pin 9 to reset a flip flop inside the trackball.

 

Another question, do you know the value of the threshold voltage on the POT inputs?

 

[ikonsgr]

As i noted before, my knowledge on atari 5200 is very limited,i don't even have an atari 5200 for tests!

So initially ,the design was based in the "theory" (and of course i used pin12 for 5v supply). But then , john_q_atari took over the job of testing it in real machine. Tests proved that using pin12 as 5v power supply (as theory suggests to do so) resulted in NON working adapter! Only when it is swapped to pot common, worked as it should (with 15pin PC gameport things are simpler as the "pot common" is actually the 5v power supply pin). I don't know why this happens, i only know that it only worked that way. Maybe john_q_atari could shed some light on the "Theory of things"... 

Edited October 25, 2019 by ikonsgr

[Swami]

10 minutes ago, ikonsgr said:

As i noted before, my knowledge on atari 5200 is very limited,i don't even have an atari 5200 for tests!

So initially ,the design was based in the "theory" (and of course i used pin12 for 5v supply). But then , john_q_atari took over the job of testing it in real machine. Tests proved that using pin12 as 5v power supply (as theory suggests to do so) resulted in NON working adapter! Only when it is swapped to pot common, worked as it should (with 15pin PC gameport things are simpler as the "pot common" is actually the 5v power supply pin). I don't know why this happens, i only know that it only worked that way. Maybe john_q_atari could shed some light on the "Theory of things"... 

I think pin 12 sets games to accept trackball input rather than joystick input.

[john_q_atari]

1 hour ago, Swami said:

I think pin 12 sets games to accept trackball input rather than joystick input.

It seems bohoki agrees with you:

https://atariage.com/forums/topic/282844-atari-5200-pin-12-spec/?do=findComment&comment=4111264

 

 

 

[john_q_atari]

1 hour ago, ikonsgr said:

As i noted before, my knowledge on atari 5200 is very limited,i don't even have an atari 5200 for tests!

So initially ,the design was based in the "theory" (and of course i used pin12 for 5v supply). But then , john_q_atari took over the job of testing it in real machine. Tests proved that using pin12 as 5v power supply (as theory suggests to do so) resulted in NON working adapter! Only when it is swapped to pot common, worked as it should (with 15pin PC gameport things are simpler as the "pot common" is actually the 5v power supply pin). I don't know why this happens, i only know that it only worked that way. Maybe john_q_atari could shed some light on the "Theory of things"... 

I don't really have anything to add unfortunately. Ikonsgr is right, when we used pin12, the adapter didn't work. when we used pot common, it did. This design is based on ikonsgr's earlier work and the bohoki adapter which is based on the adapter in the 5200 faq. You can see the link in my previous post (#104) to comments from bohoki.

 

Edited October 25, 2019 by john_q_atari

[Danjovic]

Thanks for the info, folks! I have read the thread about the pin 12 and took another look at the 5200 service manual to make some drawings to help me to summarize the information I get so far.

 

 

- Pin 12 of the joystick port is powered by one of the voltage regulators named as +5C.
- Pin 9 is powered by a variable voltage named CAV that ranges from 4V to 6.4V, according to the position of internal calibration pot R134.
- CAV voltage can be turned off by the GTIA I/O line S2.
- Trackball relies on the CAV voltage shutoff during console initialization, in fact the charging time resulting from the trackball circuit with CAV in Zero will be equivalent to a trackball with no movement. Such voltage should be close to 3 Volts. 

 

- During normal operation, moving the trackball RIGHT and DOWN should provide decrease of down to 600 mV in the "idle" voltage of POTX and POTY, which in numbers should represent a drop down to 2.4 Volts. On the other direction, LEFT and UP shall provide an increase on the voltage of up to 900 mV or 3.9 Volts.

- During console initialization the CAV voltage drops to Zero and a trackball should provide a POTn reading somewhere in the middle of the range (112). On the other hand an ordinary joystick will not have voltage to charge the capacitor, then it will return a POTn reading of 228 that is the maximum value that the POKEY counts until it "overflows" and that should be the mechanism used to differentiate a trackball from a controller.

 

From the following it is possible to derive:

 

A controller adapter powered might be powered by pin 12 as long as it uses the signal on pin 9 to "kill" any voltage at the POTX and POTY outputs to prevent the capacitors to charge, thus preventing the console to take the adapter by a trackball.

 

A device providing a voltage that varies within the range 2.4 to 3.9 volts should be look to the 5200 like a potentiometer as long as the voltage drops down to Zero when Pin 9 drops to Zero. On the other hand to emulate a trackball the voltage should go to 3V when Pin 9 falls to zero.

 

 

 

 

 

 

 

[ikonsgr]

Ok,i think it's safe to say that adapter works as it should *, so anyone interested can sent me a pm to arrange order. I currently have only 5pcbs but i ordered a bigger batch which will be available in ~month or so.

For these first 5boards cost would be 12euros+shipping (3euros standard/untracked or 5.5euros registered/tracked). This includes the extra ribbon cable for connecting a controller with keypad ,if you don't want it, price would be 10euros for a plain adapter board. 

 

 

*as  john_q_atari  reported, the only issue you might have, is a loose plug of the 15pin  D female connector when directly plugged to atari 5200 ports. Removing the metal case of the 15pin D female adpater might solve this problem (all adapters made from now on, will have the external metal case removed), in order to achieve better plugging, but still, you might need an extension cable for correct plugging of the adapter.

[Danjovic]

I was reading some posts related to the "unexpected" readings of the masterplay adapter on the intermediary positions (diagonals). Is that really an issue?

 

If so I think that some resistors can be added to extra pins on the design of the masterplay clone so it is possible to get "correct" diagonal values:

Considering the present circuit and how it works the extra resitors would be added to RC0 and RC1 //  RC4 and RA2. 

 

 

Today:
PosY  RC0  RC1  Equivalent
min   ---  ON     0 Ohm 
mid   ON   ---  47k Ohm
max   ---  ---  94k Ohm

With intermediary values:
PosY  RC0  RC1  RC2  RC3 Equivalent
min   ---  ON   ---  ---   0 Ohm 
30%   ON   ---  ON   --- 47k||68k = 27.8k
mid   ON   ---  RC2  RC3 47k Ohm
70%   ---  ---  ---  ON  (47k+47k)||220k = 65.9k
max   ---  ---  ---  --- 94k Ohm

Full Scale: 47k + 47k = 94k Ohm
30% = 28k 
50% = 47k 
70% = 66k

 

[SoundGammon]

According to Dan Kramer, the guy who designed the 5200 Trak-Ball for Atari, told me that the Trak-Ball CAN be used as a DIGITAL input!

 

I'm trying a couple of ideas and see what works!  

[BigO]

58 minutes ago, SoundGammon said:

I'm trying a couple of ideas and see what works!  

One idea. Pretty generic output can be used with many systems. If someone wrote a game to directly detect and respond to digital inputs, that would include the 5200.

[Swami]

On 10/25/2019 at 6:20 PM, Danjovic said:

Thanks for the info, folks! I have read the thread about the pin 12 and took another look at the 5200 service manual to make some drawings to help me to summarize the information I get so far.

 

Pin 12 of the joystick port is powered by one of the voltage regulators named as +5C.
- Pin 9 is powered by a variable voltage named CAV that ranges from 4V to 6.4V, according to the position of internal calibration pot R134.
- CAV voltage can be turned off by the GTIA I/O line S2.
- Trackball relies on the CAV voltage shutoff during console initialization, in fact the charging time resulting from the trackball circuit with CAV in Zero will be equivalent to a trackball with no movement. Such voltage should be close to 3 Volts. 

 

 During normal operation, moving the trackball RIGHT and DOWN should provide decrease of down to 600 mV in the "idle" voltage of POTX and POTY, which in numbers should represent a drop down to 2.4 Volts. On the other direction, LEFT and UP shall provide an increase on the voltage of up to 900 mV or 3.9 Volts.

- During console initialization the CAV voltage drops to Zero and a trackball should provide a POTn reading somewhere in the middle of the range (112). On the other hand an ordinary joystick will not have voltage to charge the capacitor, then it will return a POTn reading of 228 that is the maximum value that the POKEY counts until it "overflows" and that should be the mechanism used to differentiate a trackball from a controller.

 

From the following it is possible to derive:

 

A controller adapter powered might be powered by pin 12 as long as it uses the signal on pin 9 to "kill" any voltage at the POTX and POTY outputs to prevent the capacitors to charge, thus preventing the console to take the adapter by a trackball.

 

A device providing a voltage that varies within the range 2.4 to 3.9 volts should be look to the 5200 like a potentiometer as long as the voltage drops down to Zero when Pin 9 drops to Zero. On the other hand to emulate a trackball the voltage should go to 3V when Pin 9 falls to zero.

 

Well, I hooked pin 12 up to the pin 1 on the PC end of the bohoki with the Amiga to 15-pin PC adapter and it worked fine, so I didn't need to do anything extra. It also powered adapters that the pin 9 pot common did not. On the other hand, 5200s are notoriously divergent, so could be something different in john q atari's.

[Swami]

1 hour ago, SoundGammon said:

According to Dan Kramer, the guy who designed the 5200 Trak-Ball for Atari, told me that the Trak-Ball CAN be used as a DIGITAL input!

 

I'm trying a couple of ideas and see what works!  

What is this in response to? What is your end goal? I can tell you that what comes out of the A4 chips is potentiometric based on the speed of the trak-ball. When you reach a moderate speed, it with reach the joystick threshold, so you might have a large dead zone from the four A4 ouputs. I don't know what the ouput from the four A3 leads is like.

[Swami]

What I think would be cool would be to take the quadrature output from a USB to Amiga mouse adapter and plug it into an adapter that is constituted of the flip flop MOS to the final 5200 trak-ball output, giving you a USB mouse/trackball to 5200 adapter that allows the USB mouse/trackball to act as a cx53. This would work with all the analog games and most of the digital games. I don't think you could sell it without Dan Kramer's permission, since he has a patent on it.

[SoundGammon]

My idea is to maybe put a 9 pin connector on the back of the 5200 Trak-Ball and being able to plug any 2600 compatible joystick and use it to play 5200 games!

[Danjovic]

12 hours ago, Swami said:

What I think would be cool would be to take the quadrature output from a USB to Amiga mouse adapter and plug it into an adapter that is constituted of the flip flop MOS to the final 5200 trak-ball output, giving you a USB mouse/trackball to 5200 adapter that allows the USB mouse/trackball to act as a cx53. This would work with all the analog games and most of the digital games. I don't think you could sell it without Dan Kramer's permission, since he has a patent on it.

And what about a PS/2 mouse to 5200 adapter? I did some math and verified that it is possible to use 3 resistors to convert the 0-5V output from a microcontroller pwm into 2.4 to 3.9V that in series with a 180K, as in the trackball, should provide the adequate timing for the 5200.

[Swami]

8 minutes ago, Danjovic said:

And what about a PS/2 mouse to 5200 adapter? I did some math and verified that it is possible to use 3 resistors to convert the 0-5V output from a microcontroller pwm into 2.4 to 3.9V that in series with a 180K, as in the trackball, should provide the adequate timing for the 5200.

Or just usb to 5200 with a microcontroller. I thought about the previous method because no additional microcontroller programming is required, it's just paint by numbers, although a usb (or ps/2) to 5200 straight fix would not be patented, but you'd need a programmer.

[Danjovic]

3 minutes ago, Swami said:

Or just usb to 5200 with a microcontroller. I thought about the previous method because no additional microcontroller programming is required, it's just paint by numbers, although a usb (or ps/2) to 5200 straight fix would not be patented, but you'd need a programmer.

An Arduino board contains a bootloader, so no need to use a programmer ;).

[Swami]

4 minutes ago, Danjovic said:

An Arduino board contains a bootloader, so no need to use a programmer ;).

You need a human programmer to program for it, I mean. Most people aren't going to know what to do with an Arduino.

[ikonsgr]

1 hour ago, Danjovic said:

And what about a PS/2 mouse to 5200 adapter? I did some math and verified that it is possible to use 3 resistors to convert the 0-5V output from a microcontroller pwm into 2.4 to 3.9V that in series with a 180K, as in the trackball, should provide the adequate timing for the 5200.

Well,i've already developed an adapter that converts ps2 mouse signal to atari 2600 joystick signals, so i suppose if you combine the atari 2600 joy to 5200 adapter with this, you could use a ps2 mouse as joystick on atari 5200:-)

[Swami]

4 minutes ago, ikonsgr said:

Well,i've already developed an adapter that converts ps2 mouse signal to atari 2600 joystick signals, so i suppose if you combine the atari 2600 joy to 5200 adapter with this, you could use a ps2 mouse as joystick on atari 5200:-)

I saw an Amiga/ST mouse to joystick adapter on your site, which I own, but not a PS/2 mouse to joystick adapter.

[ikonsgr]

10 minutes ago, Swami said:

I saw an Amiga/ST mouse to joystick adapter on your site, which I own, but not a PS/2 mouse to joystick adapter.

Yes, because it's a rather new design (prototype board and program for Pic mcu is finished and tested), but i'm still waiting for some parts before... "launch"!

Actually it would be a "3 to 1" adapter, it would take a usb (ps2 compatible) mouse as input and ,using 2 small switches, convert it to:

- Amiga mouse

- Atari ST mouse

- Atari 2600 Joystick (this is the stanadrd used for joystick ports on many 80's home computers like most Atari 8bit models, Amiga, atari st, C64,Amstrad CPC, Vic 20  etc)

 

ps2/usb mouse to amiga/atari st mouse adapteres are already sold by many people on ebay, but as far as i know, this would be the 1st adapter that support the conversion of the usb(ps2 compatible) mouse to atari 2600 joystick!

 

And fortunately ebay still has tons of usb/ps2 compatible mouses available!

 

Edited November 14, 2019 by ikonsgr

[ikonsgr]

19 hours ago, Danjovic said:

I was reading some posts related to the "unexpected" readings of the masterplay adapter on the intermediary positions (diagonals). Is that really an issue?

 

If so I think that some resistors can be added to extra pins on the design of the masterplay clone so it is possible to get "correct" diagonal values:

Considering the present circuit and how it works the extra resitors would be added to RC0 and RC1 //  RC4 and RA2. 

 

Can you be more specific on this? john_q_atari   that made thorough tests of the adapter, didn't mention anything about unexpected readings.

[Swami]

9 minutes ago, ikonsgr said:

Yes, because it's a rather new design (prototype board and program for Pic mcu is finished and tested), but i'm still waiting for some parts before... "launch"!

Actually it would be a "3 to 1" adapter, it would take a usb (ps2 compatible) mouse as input and ,using 2 small switches, convert it to:

- Amiga mouse

- Atari ST mouse

- Atari 2600 Joystick (this is the stanadrd used for joystick ports on many 80's home computers like most Atari 8bit models, Amiga, atari st, C64,Amstrad CPC, Vic 20  etc)

 

ps2/usb mouse to amiga/atari st mouse adapteres are already sold by many people on ebay, but as far as i know, this would be the 1st adapter that support the conversion of the usb(ps2 compatible) mouse to atari 2600 joystick!

 

And fortunately ebay still has tons of usb/ps2 compatible mouses available!

 

If you make it so it can use left and right mouse button as joystick fire1 and joystick fire 2, it will be a first. There are three or four that can do usb/ps2 to joystick, but only fire 1 is available on all of them. 

[Swami]

45 minutes ago, ikonsgr said:

Well,i've already developed an adapter that converts ps2 mouse signal to atari 2600 joystick signals, so i suppose if you combine the atari 2600 joy to 5200 adapter with this, you could use a ps2 mouse as joystick on atari 5200:-)

We've been experimenting on a couple variations of this over on this thread. Although, commodore 64 1359/1351 mice are rare and expensive. Saw a new one on eBay for $500. My pairing of your Amiga/ST mouse to joystick adapter with a Rys or TOM USB/PS2 mouse to Amiga/ST mouse adapter works to make a USB mouse work as a two-button joystick, but the combination of microcontrollers makes it not work with PS/2 mice.

 

 

[ikonsgr]

33 minutes ago, Swami said:

If you make it so it can use left and right mouse button as joystick fire1 and joystick fire 2, it will be a first. There are three or four that can do usb/ps2 to joystick, but only fire 1 is available on all of them. 

Well,i didn't know that (at least i couldn't find any on ebay), still my version will support 2 separate fire buttons, fire 1 (pin6) left mouse button, fire 2(pin 9) right mouse button.