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This is the stuff made by me for external connection in the SMS.

1- My 315-5235 cartridge with it's original R-Type ROM
2- The board alone.
3- The backside, with the 8KB SRAM installation made by me. (I'm playing Phantasy Star again !) ;)
4- All my written eproms and flash memories. (I still have ten blank AM27C040 EPROMs to play with ... ) ;)

I'm interested in building a paddle for Alex Kidd BMX Trial ... Anyone here have the paddle and knows if it does use a
SEGA dedicated chip ? Or it uses common chips ? I will need a A/D chip to do so, but I don't have a clue of which A/D
chip I should use ... And why the game doesn't start when it's in japanese mode ? (happens in both real SMS and Meka)

Cya ...

Quote

> This is the stuff made by me for external connection in the SMS.

> 1- My 315-5235 cartridge with it's original R-Type ROM
> 2- The board alone.
> 3- The backside, with the 8KB SRAM installation made by me. (I'm playing Phantasy Star again !) ;)
> 4- All my written eproms and flash memories. (I still have ten blank AM27C040 EPROMs to play with ... ) ;)

Nice one!

I have a 315-5235 board I'd like to add the SRAM to as well. What type of chip is used for the watchdog circuit?

The mapper board looks incredibly neat, by the way. Certainly the circuit looks small enough to fit inside a SMS cartridge case, if one was to design a custom PCB for it.

Quote

> I'm interested in building a paddle for Alex Kidd BMX Trial ... Anyone here have the paddle and knows if it does use a
> SEGA dedicated chip ? Or it uses common chips ? I will need a A/D chip to do so, but I don't have a clue of which A/D
> chip I should use ...

I was in the process of designing a paddle using an Analog Devices ADC0804. No particular reason for using that chip, it was just the cheapest I could find :-)

Based on what Zoop has told me about how the paddle works, I figured that a 74HC157 - possibly two - would be needed, to select high nibble/low nibble of the 8-bit ADC output according to whether pin 7 of the controller socket is high or low.

There's also something different about the way button 2 is implemented (I forget the exact details now) which I presume games can use to detect whether a paddle is present or not, but essentially those two ICs could form the basis of a functional paddle design.

Seeing how Sega achieved it in the real paddle would be very useful, though!

> And why the game doesn't start when it's in japanese mode ? (happens in both real SMS and Meka)

What, AK BMX? It does start on a Mega Drive in Japanese mode.

This raises another question, by the way... When you say Japanese mode, do you have a Japanese SMS as well as your Tec Toy one, or have you actually managed to implement a language switch so you can change modes? If you have, I'd be very interested to know the details!

Cheers,

Mike

Sorry, the ADC0804 is made by National Semiconductor. Where did I get Analog Devices from? :-)

Here's the data sheet for it.

Mike

ADC0804 Data Sheet (PDF file)

Quote

> Nice one!

> I have a 315-5235 board I'd like to add the SRAM to as well. What type of chip is used for the watchdog circuit?

I used a Mitsumi chip, equivalent to Ohmrom BA6162 SRAM watchdog. It's the chip used in the SEGA Genesis cartridges
with 8kb SRAM, such as Phantasy star 2 ( 6264 has a non inverted CS pin. the BA6162 goes straight to the CS pin. Also, it
does stuff like controlling the SRAM consuption fro the battery while in the power down mode. Unfortunatelly I don't have a
databook of it. Since I got it from scrap, I'd just copied the connections it had on it's original circuit.
But I'm going to build a discrete watchdog circuit with a zener diode and a transistor for the SRAM circuit of the homemade
mapper.

Quote

> The mapper board looks incredibly neat, by the way. Certainly the circuit looks small enough to fit inside a SMS cartridge case, if one was to design a custom PCB for it.

I'm glad you liked it ... I want to know your opinions about my mapper schematics ... =)

Quote

> > I'm interested in building a paddle for Alex Kidd BMX Trial ... Anyone here have the paddle and knows if it does use a
> > SEGA dedicated chip ? Or it uses common chips ? I will need a A/D chip to do so, but I don't have a clue of which A/D
> > chip I should use ...

Quote

> I was in the process of designing a paddle using an Analog Devices ADC0804. No particular reason for using that chip, it was just the cheapest I could find :-)

> Based on what Zoop has told me about how the paddle works, I figured that a 74HC157 - possibly two - would be needed, to select high nibble/low nibble of the 8-bit ADC output according to whether pin 7 of the controller socket is high or low.

Neat ! Ricardo Bittencourt told me that the A/D was 4 bit only ... I'll check the TH pin status while the game is running and then I'll try to figure out how the thing should work.

Quote

> There's also something different about the way button 2 is implemented (I forget the exact details now) which I presume games can use to detect whether a paddle is present or not, but essentially those two ICs could form the basis of a functional paddle design.

A good thing to find a "hardwired" buddy in this forum is that we will have now a lot of harware wise discurssions now ! =)

Quote

> Seeing how Sega achieved it in the real paddle would be very useful, though!

I'm sure we're able to figure out the hardware side as we did with the software side of the system ... ;)

Quote

> > And why the game doesn't start when it's in japanese mode ? (happens in both real SMS and Meka)

>
> What, AK BMX? It does start on a Mega Drive in Japanese mode.

I'll try it out ... (As a collector of sega Stuff I have a TecToy MD with language/ videosystem switches)

Quote

> This raises another question, by the way... When you say Japanese mode, do you have a Japanese SMS as well as your

Tec Toy one, or have you actually managed to implement a language switch so you can change modes? If you have, I'd be very interested to know the details!

I don't have a japanese SMS. Read above:

Just tie pin 34 of 315-5216 to the GND. That pin is the TH signal (Pin 7) of the second joyport. As you know, the TH bit is bidirectional and
it seems like the Mark III software uses this for nationalization. By what I know, all games just reads this bit to find out the
nationalization for the machine.

In the megadrive it seems to be a little sort of hardwiring to the geral language bit at the jumper JP1/JP2
I'll check the effects of the TH bit on the MD latter ...

Cya ...

My homepage (not open yet)

Quote

>My homepage (not open yet)

If it's gonna be anyway related to things posted on the forum, I can provide you with webspace on smspower.org

Quote

> >My homepage (not open yet)

> If it's gonna be anyway related to things posted on the forum, I can provide you with webspace on smspower.org

Well ... It would be great. Originally I planed to make a MSX hardware page. But since 1999 my interest in the SMS
got amplified by the hardware similarities betwheen it and the MSX computers, I decided to make a hardware page for
both systems. I think I can put MSX stuff in Geocities and the SMS stuff on the webspace you're offering.

Cya ...

Author	Message
Vic_Viper Joined: 12 Jul 2005 Posts: 55	more SMS stuff pictures and Paddle for Akidd BMX Trial Posted: Mon Sep 04, 2000 3:20 am
Vic_Viper Joined: 12 Jul 2005 Posts: 55	This is the stuff made by me for external connection in the SMS. 1- My 315-5235 cartridge with it's original R-Type ROM 2- The board alone. 3- The backside, with the 8KB SRAM installation made by me. (I'm playing Phantasy Star again !) ;) 4- All my written eproms and flash memories. (I still have ten blank AM27C040 EPROMs to play with ... ) ;) I'm interested in building a paddle for Alex Kidd BMX Trial ... Anyone here have the paddle and knows if it does use a SEGA dedicated chip ? Or it uses common chips ? I will need a A/D chip to do so, but I don't have a clue of which A/D chip I should use ... And why the game doesn't start when it's in japanese mode ? (happens in both real SMS and Meka) Cya ...

Mike G Joined: 21 Apr 2000 Posts: 598 Location: Newcastle upon Tyne, England	Posted: Mon Sep 04, 2000 9:15 am
	Quote > This is the stuff made by me for external connection in the SMS. > 1- My 315-5235 cartridge with it's original R-Type ROM > 2- The board alone. > 3- The backside, with the 8KB SRAM installation made by me. (I'm playing Phantasy Star again !) ;) > 4- All my written eproms and flash memories. (I still have ten blank AM27C040 EPROMs to play with ... ) ;) Nice one! I have a 315-5235 board I'd like to add the SRAM to as well. What type of chip is used for the watchdog circuit? The mapper board looks incredibly neat, by the way. Certainly the circuit looks small enough to fit inside a SMS cartridge case, if one was to design a custom PCB for it. Quote > I'm interested in building a paddle for Alex Kidd BMX Trial ... Anyone here have the paddle and knows if it does use a > SEGA dedicated chip ? Or it uses common chips ? I will need a A/D chip to do so, but I don't have a clue of which A/D > chip I should use ... I was in the process of designing a paddle using an Analog Devices ADC0804. No particular reason for using that chip, it was just the cheapest I could find :-) Based on what Zoop has told me about how the paddle works, I figured that a 74HC157 - possibly two - would be needed, to select high nibble/low nibble of the 8-bit ADC output according to whether pin 7 of the controller socket is high or low. There's also something different about the way button 2 is implemented (I forget the exact details now) which I presume games can use to detect whether a paddle is present or not, but essentially those two ICs could form the basis of a functional paddle design. Seeing how Sega achieved it in the real paddle would be very useful, though! > And why the game doesn't start when it's in japanese mode ? (happens in both real SMS and Meka) What, AK BMX? It does start on a Mega Drive in Japanese mode. This raises another question, by the way... When you say Japanese mode, do you have a Japanese SMS as well as your Tec Toy one, or have you actually managed to implement a language switch so you can change modes? If you have, I'd be very interested to know the details! Cheers, Mike

Mike G Joined: 21 Apr 2000 Posts: 598 Location: Newcastle upon Tyne, England	ADC0804 Posted: Mon Sep 04, 2000 9:30 am
	Sorry, the ADC0804 is made by National Semiconductor. Where did I get Analog Devices from? :-) Here's the data sheet for it. Mike ADC0804 Data Sheet (PDF file)

Vic_Viper Joined: 12 Jul 2005 Posts: 55	Posted: Tue Sep 05, 2000 3:27 am
Vic_Viper Joined: 12 Jul 2005 Posts: 55	Quote > Nice one! > I have a 315-5235 board I'd like to add the SRAM to as well. What type of chip is used for the watchdog circuit? I used a Mitsumi chip, equivalent to Ohmrom BA6162 SRAM watchdog. It's the chip used in the SEGA Genesis cartridges with 8kb SRAM, such as Phantasy star 2 ( 6264 has a non inverted CS pin. the BA6162 goes straight to the CS pin. Also, it does stuff like controlling the SRAM consuption fro the battery while in the power down mode. Unfortunatelly I don't have a databook of it. Since I got it from scrap, I'd just copied the connections it had on it's original circuit. But I'm going to build a discrete watchdog circuit with a zener diode and a transistor for the SRAM circuit of the homemade mapper. Quote > The mapper board looks incredibly neat, by the way. Certainly the circuit looks small enough to fit inside a SMS cartridge case, if one was to design a custom PCB for it. I'm glad you liked it ... I want to know your opinions about my mapper schematics ... =) Quote > > I'm interested in building a paddle for Alex Kidd BMX Trial ... Anyone here have the paddle and knows if it does use a > > SEGA dedicated chip ? Or it uses common chips ? I will need a A/D chip to do so, but I don't have a clue of which A/D > > chip I should use ... Quote > I was in the process of designing a paddle using an Analog Devices ADC0804. No particular reason for using that chip, it was just the cheapest I could find :-) > Based on what Zoop has told me about how the paddle works, I figured that a 74HC157 - possibly two - would be needed, to select high nibble/low nibble of the 8-bit ADC output according to whether pin 7 of the controller socket is high or low. Neat ! Ricardo Bittencourt told me that the A/D was 4 bit only ... I'll check the TH pin status while the game is running and then I'll try to figure out how the thing should work. Quote > There's also something different about the way button 2 is implemented (I forget the exact details now) which I presume games can use to detect whether a paddle is present or not, but essentially those two ICs could form the basis of a functional paddle design. A good thing to find a "hardwired" buddy in this forum is that we will have now a lot of harware wise discurssions now ! =) Quote > Seeing how Sega achieved it in the real paddle would be very useful, though! I'm sure we're able to figure out the hardware side as we did with the software side of the system ... ;) Quote > > And why the game doesn't start when it's in japanese mode ? (happens in both real SMS and Meka) > > What, AK BMX? It does start on a Mega Drive in Japanese mode. I'll try it out ... (As a collector of sega Stuff I have a TecToy MD with language/ videosystem switches) Quote > This raises another question, by the way... When you say Japanese mode, do you have a Japanese SMS as well as your Tec Toy one, or have you actually managed to implement a language switch so you can change modes? If you have, I'd be very interested to know the details! I don't have a japanese SMS. Read above: Just tie pin 34 of 315-5216 to the GND. That pin is the TH signal (Pin 7) of the second joyport. As you know, the TH bit is bidirectional and it seems like the Mark III software uses this for nationalization. By what I know, all games just reads this bit to find out the nationalization for the machine. In the megadrive it seems to be a little sort of hardwiring to the geral language bit at the jumper JP1/JP2 I'll check the effects of the TH bit on the MD latter ... Cya ... My homepage (not open yet)

Zoop Joined: 24 Jun 1999 Posts: 1732 Location: Paris, France	Homepage Posted: Tue Sep 05, 2000 6:19 pm
	Quote >My homepage (not open yet) If it's gonna be anyway related to things posted on the forum, I can provide you with webspace on smspower.org

Vic_Viper Joined: 12 Jul 2005 Posts: 55	Re: Homepage Posted: Wed Sep 06, 2000 3:16 am
Vic_Viper Joined: 12 Jul 2005 Posts: 55	Quote > >My homepage (not open yet) > If it's gonna be anyway related to things posted on the forum, I can provide you with webspace on smspower.org Well ... It would be great. Originally I planed to make a MSX hardware page. But since 1999 my interest in the SMS got amplified by the hardware similarities betwheen it and the MSX computers, I decided to make a hardware page for both systems. I think I can put MSX stuff in Geocities and the SMS stuff on the webspace you're offering. Cya ...

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