MegaDrive++ : new switchless region + IGR mod

I'm working on a all in one board that includes your switchless mod and the switchable oscillator.

I believe the 2313s arrived awhile ago. But just not got around to testing yet!!

 

Hi guys !

So i could finally set my IGR nano mod.

Damn, that wasn't a piece of cake, i spent a full morning on this. Yeah, the nano part is somehow simple, lemme explain.

First, i had to install the Nano drivers, and then the flashing soft. Everything seemd to go well, except that f*ckin' Windows alert "It seems that this software didn't install correctly, wwaht do you want to do, etc..." So you never know if you did right... well, let's see.

The flashing soft is pretty self explanatory... IN ENGLISH. In french, the translation is so bad it's rather hard to get what you have to do. Plus, i dunno why, but my first try to flash the Nano (in french so) failed. As i thought i choose the wrong option, i switched to english language. It appears that i had chosen the good action in first. I tried in english, and this time it was a success.

So, i had my freshly flashed Nano in the hand. I must add that i changed the code line to drive a green/red LED (but no luck, my LED has its yellow almost red too, the difference is very very tiny, i think the red is too strong compared to the green intensity).

For the intallation, i choose my already modded MegaDrive. Removed that good ol' switch, cut some traces, soldered everything according to diagram.
Then connect everything to TV and AC, insert a game, turn ON and... a picture. CoOol !
But... no sound. No sound ? what the * ? Check once, twice... no sound. Try IGR, refresh change.. no effect. Strange behaviors. The Reset button seems to work normally though.
Remove game, insert my MegaEverDrive. Stuck to blue screen. WHAAAAT ?

Start to sweat...

First news check... i swapped the wires of controller pin 9 and pin 7. What a dumb -_-. Never NEVER do such work with children around you a sunday morning...
Fix the thing... turn On... No sound...GHAAAAAAAA !
Disconnect the Nano, short the jumpers for 50 or 60 Hz... the sound is back. BUT WHY THIS F$#¤ WILL WASTE MY SUNDAY MORNIN' ?
Check again and again... Hey, i forgot that that MegaDrive was modded for Overclock...
Remove the overclock mod, restore the trace. Sound is back... Damn... the overclock mod is somehow rerouting some clock signal from game port to clock pin of processor. Is the "normal clock" signal not as normal as the original ? It's getting more and more weird. And i'm getting more and more upset...
Restore the overclock mod, 50-60Hz switch too. New test... WhaAat ? My console is stuck in 60Hz, so i can't even boot my game as i get that "This gamepak is designed for PALetc" message. RHAAAAA F$#¤ shitty sunday !!
Some more test.. my switch juts died -_-

Well, keep calm, drink a coffee, back to the beginning.

I restore all the original setting of this MegaDrive (50-60Hz and Overclock), take another MegaDrive and redo the whole soldering job.

And Voila ! everything working flawlessly

So TL;DR : i can't know for sure, as i had so many issue during the installation, but could it be possible that the overclock mod (even in normal setting) has something wrong with the Nano mod ?

Some other question : how do you dim the two colors green and red of the LED ? I would like a yellow more... yellow (well, more different to the full red).

And last but not least, could it be possible to adapt this wondeful mod to the MasterSystem, and so drive the Reset, Pause and Refresh function by sniffing the controller pad ?

Thank you (and congratulation) for reading !

 

Glad you got to a working situation in the end . I don't know anything about the overclock mod, so I don't really know what to say, can you provide a link on how it's done?

To have a dimmer green I would suggest to just use a bigger resistor on the green leg, something like 680 Ohm (and 220 on the red leg). I usually test resistor values with the led before installing them, until I am satisfied with the colors.

It would probably be trivial to make a Master System version of this. The worst part would be finding satisfactory key combos to trigger the functions, since the MS pad doesn't have many keys. Actually it would probably be better to trigger them through key sequences rather than through combos. This is slightly more difficult but it's doable.

PS: Got my 2313A's!

 

thank you for your comments
here is a link to the mod i did (it's a very old tut' i made so long ago... but i hope it'll hellp you).
http://gueux-forum.net/index.php?/topic/162491-tuto-megadrive-overclock/

'bout the MasterSystem mod, i did myself a mod that uses "gate chip", inspired from this work :
http://www.smspower.org/Development/JoypadPauseButton
Don't ask me more, i'm really noob at electronic
TL;DR : the mod consist in adding a button that will activate a D-Pad direction line (let's say Right). Then, by pressing this button and the D-Pad left, you create a combo usually impossible to do, used to activate the Reset function.
I added a second button so i can activate the Pause too.
Modding the controller could be a solution, but too heavy, and not in the mood of a simple mod.

Another idea inspired from my Atari2600 RGB experience. Tim Worthington (creator of NESRGB and 2600RGB) use something similar to drive his board, by adding a button on the controller (the original one has only one button).
I personnaly used an Amstrad GX4000 controller that has a second button, that i used as an "alt" button.
SO my question : do you think we could use a MegaDrive controller on the MasterSystem in order to add some button function ?
I'm at my work now and can't check for both controller pinouts. Just an idea

See ya !

 

Judging from your tutorial I really see no reason for the overclock to interfere with any MegaDrive++ functions, and even less reasons for it to mute any sounds. I don't feel comfortable with overclocking anything, so I cannot really reproduce the issue.

Got it about the Master System mod, but again, I don't feel comfortabile drilling holes and installing extra buttons in my gamepads. Unfortunately using the MegaDrive pad's extra buttons on a MS can be done, but has some side effects: the Start and A buttons use the same signal lines as the C and B buttons. I could detect when Start is pressed and pause the CPU, but the MS game would register a press of the C button, which maps to button 1 of the MS pad. Ditto for A.

To avoid that, I can think of two ways:
1. Pause the CPU for a brief moment while the pad is sampled: since this must be done at least 10 times a second or so, it would hardly go unnoticed.
2. Reroute pins 6 and 9 of the gamepad port to the modchip: this means that the connections of said pins to the MS mainboard should be severed, and then the modchip would be connected to the mainboard and properly drive the signals. This probably sounds harder to do than it actually is , but I would need another MS to experiment, as I only have one which is in pretty good conditions and thus serves for collection purposes. This idea just came to my mind while I was typing the above, gonna head to eBay, LOL!

PS: Did some testing of MD++ on 2313A's and it seems to work fine!

 

For completeness

 

Looks cool @Bad_Ad84, but I prefer the other side .

Has anyone noticed this: https://vmod.wordpress.com/megamod-v3-0/? It is based on MegaDrive++ and adds a switchable audio filter.

PS: Got myself a second Master System, gonna try to make that other mod!

 

Yeah, that looks cool!

 

Bad_Add84: don't suppose you could make the combined DFO/Mod board mount on the oscillator posts internally like the DFO itself does? Would save a bit of wiring and would secure it properly inside the console too.

another suggestion is connector ports for the cabling - you could sell (pre sized) wiring kits too!

 

Well, after quite a bit of work, the Master System mod is almost done:


Gonna open a new thread ASAP .

 

'llo here
Back from hollidays, and such a good new !Glad you finally could take a look over that MasterSystem !
Very excited waiting foryour report !
See ya, and thank you once again !

 

I've installed this in a VA5 japanese MD alongside a DFO and everything appears to work fine, until i use the boost in super hang-on...

Somehow after the console has been running for a few minutes it will reset when pressing B and C together, no other button combo does this (except start+a+b+c of course) and i can't reproduce it in other games, only super hang-on!
I'll have to go triple check my wiring when i find some time...

 

I would suggest to check the wiring of pin 7 in particular, and maybe 6 and 9. There may be other reasons though, I can't test as I don't have that game. Could anybody else with the mod try it?

 

I've checked everything but can't find any fault with the wiring, no shorts between the pins either.
The only games i have on hand is a "Mega Games 1" cartridge containing hang-on, colums and some football game, it only happens in hang-on even trying to provoke it...
Happens in all three modes with three and six button controllers.
I wonder if it's a brown-out issue with the arduino nano but the LED stays lit and i'm powering from the region jumpers just like keropi.

Next step will be turning the arduino off entirely and trying it with just the DFO and hardwired jumpers.

 

Then it might very well be a software problem. I will try to get hold of the cartridge and to reproduce the issue.

There's no need to turn off the Arduino, you can just try to temporarily disconnect the Reset Out signal.

 

Yep that does sound like the easier way to test it and so i did it, with the disconnected Reset Out wire everything runs fine through multiple levels, i guess that rules out my DFO as the culprit.
I made extra sure that the reset trace is cut properly so that shouldn't be it either. Sure enough once the wire is reconnected the problem occurs again, hold B+C for a second and the system resets.

The sketch i flashed had the LED colours changed to not use the blue channel, i somehow doubt that's the cause.

Edit: I've found out how to reproduce it, hold B+C and wiggle the dpad left and right. after a few times the console resets every time no matter which software is running.

 

OK, bug is confirmed.

What Arduino did you use for your mod?

If I provide you with updated code containing a tentative fix, are you able to upload the new code to the Arduino?

 

Going to install sometime this week.