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I had this same issue before and reflowing some solder to where the DB-9-like connectors are for the controllers resolved this issue.

^^^^Thank you

Still not working.

Also, you have the FM board as well? Take that out of there and see if it fixes anything. I remember having issues with it and my Pro Action Replay. I don't think there is a flaw in tim's design but maybe it's not seated properly on the expansion slot or soldered appropriately, etc.

I installed the language mod first, got the shits and installed the FM board after wards. Tim has modified it to work with this mod (rev1.1 board). I also removed the 2 port pause mod (which has a slight boo-boo in the development section) as well. No luck.

*Edit is worth while changing the 74LSxxx with 74HCxxx?

I forgot to mention I had another SMS that had this issue. Have you tried taking the various solder points near that DB-9 connector and grounding them to see if they still function?

I soldered small jumpers from those EMxx (whatever those things are, they have 3 pins on them) to the appropriate places they went to and that fixed the issue on that particular SMS.

This is most annoying, I transfered this over to another master system 2 and no go!

Do you mean you ran additional wires from the EM filters to the final destination?
Do you have any pics to show what you mean please? Just asking how this would affect this mod as it isn't connected to the control ports?

I am going to Jaycar tomorrow to grab some other 74LS125/138 as well as some 74HC variants and try that. perhaps I have been given dodgy chips.

My only other option is to send these boards back to Tim to get changed back to accept the original mod (ie pin 23 and hold left to get WB3 to work in FM sound) as this is starting to really piss me off.

Oh! You're fucked with WB3 and FM brother.

Just get a Pro Action Replay or get a hacked ROM that disables that stupid ass check. The holding left is a dodgy hack that actually doesn't work.

I highly recommend getting a PAR for your SMS. Not only can you bypass these silly checks, you can open up a whole new world to hacking your games. I found one on ebay without the box and manual for $15 USD plus $10 shipped from germany a year or so ago. So it's possible to get it without paying $100 for a complete boxed version.

Hmmm thing is this SMS2 is for a mate of mine, would like to get this working.

My old SMS2 (with the old language mod - GND pin 23) works ok with the hold left trick.

On this console (the one for my friend) I tried the old language mod and hold left with this new FM board and it didn't work, perhaps due to the new design and the fact it is supposed to work with the new language mod (which I can't get to work lol)!

I went to Jaycar today and got some name brand 74LSxxx chips, I am going to re-visit this and cross my fingers these chips while appearing to be ok are actually dodgy in some way.

Keep us updated. But, there was an exhaustive thread where even I asked about how to get this working and it was discovered that it was a weird, dodgy hack and you're lucky if it works for you.

Seriously though, I highly recommend a PAR if you can't get anywhere with this (and even if you can!)

Didn't work with the other chips. Most frustrating.

I had a look at PAR's on ebay, bloody expensive! I will keep an eye out.

*Edit Do you have a link to this exhaustive thread please?

http://www.smspower.org/forums/viewtopic.php?t=12481&postdays=0&postorde...

http://www.smspower.org/forums/viewtopic.php?t=12718&highlight=

And of course, earlier posts in this thread.

omp wrote

I had a look at PAR's on ebay, bloody expensive! I will keep an eye out.

You have to look on international ebay sites for it. They will show up, you might have to sit on it for awhile though. I waited a few months before I saw one for auction and not some ridiculous buy it now crap.

Omp sent his Master System to me after he couldn't get Charles's modification to work.

After playing with it for a bit, I can say with certainty that this region modification doesn't work, or at least doesn't work reliably.

If you think about how it works... the idea is to prevent a write to the I/O register at port $3F. It does this by monitoring the bus for a write and shutting off the I/O controller when one is detected. But this doesn't work because by the time a write to port $3F is detected, it has already happened. The circuit depends on the logic being fast enough to shut off the I/O controller before the write takes place. And it isn't fast enough.

If you were to replace the 74LS125 switching element with a PNP transistor, as I have done, the circuit will actually work, although for the wrong reasons. I recorded the waveform at the collector on my oscilloscope to see why this was working, while the 'LS125 was not. The transistor has a base resistor of 4.7k and is driven deeply into saturation. This, and the asymmetrical drive from the logic gate causes the transistor to remain on for an extended period of time.

This will thwart the export SMS region detection routine, but in an unexpected way. The code works by setting the TH output and reading the value back in the next instruction. The transistor switch is too slow to prevent the write to $3F, but stays on for a few extra instruction cycles and ends up blocking the read from $DD instead.

I have come up with another region modification that I hope will put an end to problems like this. It doesn't disable the I/O controller, instead it prevents the /IOReq signal from getting to it if the address $3F or one of its mirrors is detected on the bus. The major disadvantage compared to Charles's circuit is that the IORQ line to the I/O controller must be intercepted. For the SMS2 board layout, the only practical way to go about this is to cut the pin at the chip with a pair of side cutters and solder onto the stub.

sega0.png (2.32 KB)

CH1 = 74LC128-Y0 CH2 = Transistor-collector

SMSregion.PNG (4.09 KB)

Quote

The circuit depends on the logic being fast enough to shut off the I/O controller before the write takes place. And it isn't fast enough.

Nice detective work!

I implemented the region mod using a 15-ns 22V10 GAL and that worked fine. But using a 74LS138 and 74LS125 together gives a much longer propagation delay as you found.

The 74F138 and 74F125 seem fast enough, but are there other reasons not to use them in the SMS? I'm not too familiar with those parts.

EDIT:

Now I'm curious why this fails exactly. Assuming worst-case timings, the original circuit will still assert KILLGA well before the rising edge of WR# at the end of the port write. How much of an overshoot were you seeing time-wise? Even 74HCT parts should be fast enough to do it.

It could be that KILLGA won't really 'cancel' the write that was in progress, but it does work consistently on my machine using the GAL, unless that is a fluke of some kind.

Maybe it just latches garbage during a write that's been interrupted by KILLGA and that's where the variable behavior comes from on different systems?

Awesome. Now I just need to find a spare SMS to play around with.

Well I am glad it wasn't me. I was half expecting "Ah you have this wired wrong dumb-ass".

When I get the console back, I will have to do this for myself (in another console). Any problem with using a CD4071 OR gate instead of the 7432?

Oh and thank you for looking at it and solving the problem!

Well I got the console back from Tim and while the Japanese mode works, unfortunately the FM board still won't with WB3......

How bad do you want it and how bad do you want to spend more time on it? That's why I gave up and just got the PAR.

You could also just patch the ROM, but you'd need an EEPROM burner. Either option would work out well.

Well it was for a mate, as I was telling him about my SMS2 (with original FM board and old language switch) and how much better WB3 sounds with the FM board. Mentioned with mine I had to hold left and button 1 for the FM sound to work but was worth it. He was keen for the same, so I ordered 2 boards, 1 for him and one for myself to "revise" my old SMS2 (to the new "safer" language mod).

I just feel like a right prick as I essentially promised my mate the same setup as my SMS2 (minus the RGB out) and I can't deliver on that promise, as I was unaware that the new board (modified further to suit the new mod) was incompatible with WB3. I have PM'ed Tim, I want to have these boards de-modified or swapped over, I will do the old language switch mod, I no longer give a....... These things are starting to cost me a small fortune, I sent my SMS2 down, paid for it to be looked at, paid for it to be sent back.

I stewed on it yesterday after getting my SMS2 back thinking it was all sweet and I am pretty *^$^*#%& pissed off about it. Just my luck to be the guinea pig for this.

Yeah, I hear ya. Tim's a reasonable guy though. I see no reason why he wouldn't help to make it right.

He certainly is, wasn't having a go at him. Just annoyed at the whole situation. WB3 is a bitch of a game and unfortunately we may not be able to have our cake and eat it too with this one.

Have discussed with him about taking the boards back to standard and the possibility that it *may* work. The reason why it was modified in the first place is due to the KILLGA (thingy-ma-jiggy) being used in the mod. Since Tim came up with this new one there is no need to modify the board. I am going to try it this weekend or thereabouts.

I really have to calm down lol, I already have issued myself a ban from Sega-16 because I went a bit nuts over there trying to explain myself and failing miserably.

It hasn't been 100% verified if the KILLJOY/KILLGA is the issue. I brought it to his attention that a mix of my PAR and his FM unit was occasionally fudging things up.

I wish someone out there had the time to seriously reverse engineer the PAR and do a small run for about $50-$60 range. I'd stock up on a couple.

Well done to Tim!

I de-modifed the FM board and tried WB3, works straight off the bat, no need to hold left/button. Just plug the game in and BANG! done!

Pretty sweet, how much did he charge to do the region mod and is it the complex method thats been described in this thread?

Well I sent it down originally as the mod by charles refused to work (used multiple sets of IC's etc). Tim came up with the new one (as he posted above). This one to me is simpler as it just uses a NAND and OR gate which I understand so is less daunting to me. I had asked Tim since this mod doesn't interfere with JOYKILL, would in his opinion, work if I reverted his FM board back to standard (as his earlier post states with Charles's mod his FM board requires modding). He wasn't 100% sure, so I thought I had nothing to lose, undone the mod and PRESTO! So in short if you have a (PAL) SMS2 and want a FM board, get off Tim a STANDARD FM board and do his Japanese mod. Tim charged me $40 to look at it and I paid for postage both ways so about $70-80 all up (lucky I live in the same country).

*EDIT* Also confirmed with console in Japanese mode the light gun will work!

For the first schematic posted by Charles McDonald:

For a noob figuring this out:

- Do I lift 315-5216 pin 23 or hot wire on it?
- I need one 74LS125 and one 74LS138?
i.e: those spare gates are all in the same chip?
(Not used to deciphering schematics.)

Thanks.

rrobertsen wrote

- Do I lift 315-5216 pin 23 or hot wire on it?
- I need one 74LS125 and one 74LS138?
i.e: those spare gates are all in the same chip?

Don't lift it, just solder a wire directly to pin 23.

Usually for console mods you do lift pins, but this is one of those situations where you don't.

You do need one 74LS125 chip and one 74LS138 chip.

The spare gates just show how to connect the unused pins of the 74LS125. It has four buffers in it and we're only using one, so the schematic is showing what to do with the unused pins on the remaining three buffers.

If the mod works well for you, I'd love to hear about it. :)

Please note, when omp built this circuit it didn't work. It may not work for you. Tim posted a different schematic in this thread which did work for omp, so you may want to consider building that instead.

Yes it depends which revision of Master System you have. It didn't work in a SMS2 and I would assume it *may* not work in a VA3 SMS model 1 since it uses the same I/O IC.

Linked to that topic:
http://www.smspower.org/forums/16249-SamsungGamBoyRegionDetection
Also http://www.smspower.org/forums/13423

- Samsung Gam-Boy 1 modelled after Japanese SMS comes in two variants: one has the FM chip or doesn't appear to have it.
- Yamasa note that his console (without FM chip) appears to boot the Export and Japanese roms of Wonder Boy Monster Land respectively with English and Japanese language. This isn't consistent with that happens with testing the same roms in an emulator where the region dictate the language.

Author	Message
Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Wed Feb 08, 2012 6:44 pm
	I had this same issue before and reflowing some solder to where the DB-9-like connectors are for the controllers resolved this issue.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Thu Feb 09, 2012 12:00 am
omp Joined: 13 Nov 2007 Posts: 219	^^^^Thank you Still not working.

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Thu Feb 09, 2012 1:19 am
	Also, you have the FM board as well? Take that out of there and see if it fixes anything. I remember having issues with it and my Pro Action Replay. I don't think there is a flaw in tim's design but maybe it's not seated properly on the expansion slot or soldered appropriately, etc.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Thu Feb 09, 2012 5:16 am
omp Joined: 13 Nov 2007 Posts: 219	I installed the language mod first, got the shits and installed the FM board after wards. Tim has modified it to work with this mod (rev1.1 board). I also removed the 2 port pause mod (which has a slight boo-boo in the development section) as well. No luck. *Edit is worth while changing the 74LSxxx with 74HCxxx?

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Fri Feb 10, 2012 1:05 am
	I forgot to mention I had another SMS that had this issue. Have you tried taking the various solder points near that DB-9 connector and grounding them to see if they still function? I soldered small jumpers from those EMxx (whatever those things are, they have 3 pins on them) to the appropriate places they went to and that fixed the issue on that particular SMS.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Fri Feb 10, 2012 2:59 am
omp Joined: 13 Nov 2007 Posts: 219	This is most annoying, I transfered this over to another master system 2 and no go! Do you mean you ran additional wires from the EM filters to the final destination? Do you have any pics to show what you mean please? Just asking how this would affect this mod as it isn't connected to the control ports? I am going to Jaycar tomorrow to grab some other 74LS125/138 as well as some 74HC variants and try that. perhaps I have been given dodgy chips. My only other option is to send these boards back to Tim to get changed back to accept the original mod (ie pin 23 and hold left to get WB3 to work in FM sound) as this is starting to really piss me off.

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Sat Feb 11, 2012 12:28 am
	Oh! You're fucked with WB3 and FM brother. Just get a Pro Action Replay or get a hacked ROM that disables that stupid ass check. The holding left is a dodgy hack that actually doesn't work. I highly recommend getting a PAR for your SMS. Not only can you bypass these silly checks, you can open up a whole new world to hacking your games. I found one on ebay without the box and manual for $15 USD plus $10 shipped from germany a year or so ago. So it's possible to get it without paying $100 for a complete boxed version.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Sat Feb 11, 2012 6:05 am
omp Joined: 13 Nov 2007 Posts: 219	Hmmm thing is this SMS2 is for a mate of mine, would like to get this working. My old SMS2 (with the old language mod - GND pin 23) works ok with the hold left trick. On this console (the one for my friend) I tried the old language mod and hold left with this new FM board and it didn't work, perhaps due to the new design and the fact it is supposed to work with the new language mod (which I can't get to work lol)! I went to Jaycar today and got some name brand 74LSxxx chips, I am going to re-visit this and cross my fingers these chips while appearing to be ok are actually dodgy in some way.

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Mon Feb 13, 2012 4:09 pm
	Keep us updated. But, there was an exhaustive thread where even I asked about how to get this working and it was discovered that it was a weird, dodgy hack and you're lucky if it works for you. Seriously though, I highly recommend a PAR if you can't get anywhere with this (and even if you can!)

omp Joined: 13 Nov 2007 Posts: 219	Posted: Mon Feb 13, 2012 8:20 pm
omp Joined: 13 Nov 2007 Posts: 219	Didn't work with the other chips. Most frustrating. I had a look at PAR's on ebay, bloody expensive! I will keep an eye out. *Edit Do you have a link to this exhaustive thread please?

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Tue Feb 14, 2012 5:24 pm
	http://www.smspower.org/forums/viewtopic.php?t=12481&postdays=0&postorde... http://www.smspower.org/forums/viewtopic.php?t=12718&highlight= And of course, earlier posts in this thread.

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Tue Feb 14, 2012 5:24 pm
	omp wrote I had a look at PAR's on ebay, bloody expensive! I will keep an eye out. You have to look on international ebay sites for it. They will show up, you might have to sit on it for awhile though. I waited a few months before I saw one for auction and not some ridiculous buy it now crap.

viletim Joined: 24 Sep 2006 Posts: 191 Location: Sydney, Australia	Posted: Sun Feb 26, 2012 11:55 am
	Omp sent his Master System to me after he couldn't get Charles's modification to work. After playing with it for a bit, I can say with certainty that this region modification doesn't work, or at least doesn't work reliably. If you think about how it works... the idea is to prevent a write to the I/O register at port $3F. It does this by monitoring the bus for a write and shutting off the I/O controller when one is detected. But this doesn't work because by the time a write to port $3F is detected, it has already happened. The circuit depends on the logic being fast enough to shut off the I/O controller before the write takes place. And it isn't fast enough. If you were to replace the 74LS125 switching element with a PNP transistor, as I have done, the circuit will actually work, although for the wrong reasons. I recorded the waveform at the collector on my oscilloscope to see why this was working, while the 'LS125 was not. The transistor has a base resistor of 4.7k and is driven deeply into saturation. This, and the asymmetrical drive from the logic gate causes the transistor to remain on for an extended period of time. This will thwart the export SMS region detection routine, but in an unexpected way. The code works by setting the TH output and reading the value back in the next instruction. The transistor switch is too slow to prevent the write to $3F, but stays on for a few extra instruction cycles and ends up blocking the read from $DD instead. I have come up with another region modification that I hope will put an end to problems like this. It doesn't disable the I/O controller, instead it prevents the /IOReq signal from getting to it if the address $3F or one of its mirrors is detected on the bus. The major disadvantage compared to Charles's circuit is that the IORQ line to the I/O controller must be intercepted. For the SMS2 board layout, the only practical way to go about this is to cut the pin at the chip with a pair of side cutters and solder onto the stub. sega0.png (2.32 KB) CH1 = 74LC128-Y0 CH2 = Transistor-collector SMSregion.PNG (4.09 KB)

Charles MacDonald Joined: 28 Sep 1999 Posts: 1197	Posted: Sun Feb 26, 2012 5:22 pm Last edited by Charles MacDonald on Wed Feb 29, 2012 3:30 am; edited 1 time in total
Charles MacDonald Joined: 28 Sep 1999 Posts: 1197	Quote The circuit depends on the logic being fast enough to shut off the I/O controller before the write takes place. And it isn't fast enough. Nice detective work! I implemented the region mod using a 15-ns 22V10 GAL and that worked fine. But using a 74LS138 and 74LS125 together gives a much longer propagation delay as you found. The 74F138 and 74F125 seem fast enough, but are there other reasons not to use them in the SMS? I'm not too familiar with those parts. EDIT: Now I'm curious why this fails exactly. Assuming worst-case timings, the original circuit will still assert KILLGA well before the rising edge of WR# at the end of the port write. How much of an overshoot were you seeing time-wise? Even 74HCT parts should be fast enough to do it. It could be that KILLGA won't really 'cancel' the write that was in progress, but it does work consistently on my machine using the GAL, unless that is a fluke of some kind. Maybe it just latches garbage during a write that's been interrupted by KILLGA and that's where the variable behavior comes from on different systems?

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Sun Feb 26, 2012 6:27 pm
	Awesome. Now I just need to find a spare SMS to play around with.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Sun Feb 26, 2012 9:25 pm
omp Joined: 13 Nov 2007 Posts: 219	Well I am glad it wasn't me. I was half expecting "Ah you have this wired wrong dumb-ass". When I get the console back, I will have to do this for myself (in another console). Any problem with using a CD4071 OR gate instead of the 7432? Oh and thank you for looking at it and solving the problem!

omp Joined: 13 Nov 2007 Posts: 219	Posted: Sat Mar 24, 2012 5:44 am
omp Joined: 13 Nov 2007 Posts: 219	Well I got the console back from Tim and while the Japanese mode works, unfortunately the FM board still won't with WB3......

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Sat Mar 24, 2012 3:26 pm
	How bad do you want it and how bad do you want to spend more time on it? That's why I gave up and just got the PAR. You could also just patch the ROM, but you'd need an EEPROM burner. Either option would work out well.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Sat Mar 24, 2012 9:47 pm
omp Joined: 13 Nov 2007 Posts: 219	Well it was for a mate, as I was telling him about my SMS2 (with original FM board and old language switch) and how much better WB3 sounds with the FM board. Mentioned with mine I had to hold left and button 1 for the FM sound to work but was worth it. He was keen for the same, so I ordered 2 boards, 1 for him and one for myself to "revise" my old SMS2 (to the new "safer" language mod). I just feel like a right prick as I essentially promised my mate the same setup as my SMS2 (minus the RGB out) and I can't deliver on that promise, as I was unaware that the new board (modified further to suit the new mod) was incompatible with WB3. I have PM'ed Tim, I want to have these boards de-modified or swapped over, I will do the old language switch mod, I no longer give a....... These things are starting to cost me a small fortune, I sent my SMS2 down, paid for it to be looked at, paid for it to be sent back. I stewed on it yesterday after getting my SMS2 back thinking it was all sweet and I am pretty ^$^#%& pissed off about it. Just my luck to be the guinea pig for this.

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Mon Mar 26, 2012 3:18 am
	Yeah, I hear ya. Tim's a reasonable guy though. I see no reason why he wouldn't help to make it right.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Mon Mar 26, 2012 3:51 am
omp Joined: 13 Nov 2007 Posts: 219	He certainly is, wasn't having a go at him. Just annoyed at the whole situation. WB3 is a bitch of a game and unfortunately we may not be able to have our cake and eat it too with this one. Have discussed with him about taking the boards back to standard and the possibility that it may work. The reason why it was modified in the first place is due to the KILLGA (thingy-ma-jiggy) being used in the mod. Since Tim came up with this new one there is no need to modify the board. I am going to try it this weekend or thereabouts. I really have to calm down lol, I already have issued myself a ban from Sega-16 because I went a bit nuts over there trying to explain myself and failing miserably.

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Mon Mar 26, 2012 5:23 am
	It hasn't been 100% verified if the KILLJOY/KILLGA is the issue. I brought it to his attention that a mix of my PAR and his FM unit was occasionally fudging things up. I wish someone out there had the time to seriously reverse engineer the PAR and do a small run for about $50-$60 range. I'd stock up on a couple.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Fri Mar 30, 2012 8:34 pm
omp Joined: 13 Nov 2007 Posts: 219	Well done to Tim! I de-modifed the FM board and tried WB3, works straight off the bat, no need to hold left/button. Just plug the game in and BANG! done!

Maraakate Joined: 05 Jun 2010 Posts: 757 Location: Pennsylvania, USA	Posted: Sun Apr 01, 2012 3:47 am
	Pretty sweet, how much did he charge to do the region mod and is it the complex method thats been described in this thread?

omp Joined: 13 Nov 2007 Posts: 219	Posted: Sun Apr 01, 2012 9:31 am
omp Joined: 13 Nov 2007 Posts: 219	Well I sent it down originally as the mod by charles refused to work (used multiple sets of IC's etc). Tim came up with the new one (as he posted above). This one to me is simpler as it just uses a NAND and OR gate which I understand so is less daunting to me. I had asked Tim since this mod doesn't interfere with JOYKILL, would in his opinion, work if I reverted his FM board back to standard (as his earlier post states with Charles's mod his FM board requires modding). He wasn't 100% sure, so I thought I had nothing to lose, undone the mod and PRESTO! So in short if you have a (PAL) SMS2 and want a FM board, get off Tim a STANDARD FM board and do his Japanese mod. Tim charged me $40 to look at it and I paid for postage both ways so about $70-80 all up (lucky I live in the same country). EDIT Also confirmed with console in Japanese mode the light gun will work!

rrobertsen Joined: 24 Dec 2011 Posts: 29 Location: Norway	Posted: Fri May 17, 2013 3:18 pm
	For the first schematic posted by Charles McDonald: For a noob figuring this out: - Do I lift 315-5216 pin 23 or hot wire on it? - I need one 74LS125 and one 74LS138? i.e: those spare gates are all in the same chip? (Not used to deciphering schematics.) Thanks.

Charles MacDonald Joined: 28 Sep 1999 Posts: 1197	Posted: Fri May 17, 2013 3:40 pm
Charles MacDonald Joined: 28 Sep 1999 Posts: 1197	rrobertsen wrote - Do I lift 315-5216 pin 23 or hot wire on it? - I need one 74LS125 and one 74LS138? i.e: those spare gates are all in the same chip? Don't lift it, just solder a wire directly to pin 23. Usually for console mods you do lift pins, but this is one of those situations where you don't. You do need one 74LS125 chip and one 74LS138 chip. The spare gates just show how to connect the unused pins of the 74LS125. It has four buffers in it and we're only using one, so the schematic is showing what to do with the unused pins on the remaining three buffers. If the mod works well for you, I'd love to hear about it. :) Please note, when omp built this circuit it didn't work. It may not work for you. Tim posted a different schematic in this thread which did work for omp, so you may want to consider building that instead.

omp Joined: 13 Nov 2007 Posts: 219	Posted: Sat May 18, 2013 9:48 am
omp Joined: 13 Nov 2007 Posts: 219	Yes it depends which revision of Master System you have. It didn't work in a SMS2 and I would assume it may not work in a VA3 SMS model 1 since it uses the same I/O IC.

Bock Site Admin Joined: 08 Jul 2001 Posts: 8652 Location: Paris, France	Odd regions detection in Samsung system Posted: Sat Aug 13, 2016 11:43 am
	Linked to that topic: http://www.smspower.org/forums/16249-SamsungGamBoyRegionDetection Also http://www.smspower.org/forums/13423 - Samsung Gam-Boy 1 modelled after Japanese SMS comes in two variants: one has the FM chip or doesn't appear to have it. - Yamasa note that his console (without FM chip) appears to boot the Export and Japanese roms of Wonder Boy Monster Land respectively with English and Japanese language. This isn't consistent with that happens with testing the same roms in an emulator where the region dictate the language.

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