Found Modded mega drive 1
- Thread starter slk486
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I need to read up on the whole 12.5 mhz 4 pin oscillators, arent they for if you're not using RGB?
---------- Post added at 00:19 ---------- Previous post was at 00:05 ----------
Right I just read up. Where I buy? lol.
---------- Post added at 00:19 ---------- Previous post was at 00:05 ----------
Right I just read up. Where I buy? lol.
r0jaws
Mondeo Man
Time for an update. I had some time last night and today to get this sorted out.
The MD I bought from Taj is in reasonable condition, I'll give the plastics a bit of a clean up once I'm finished. The expansion cover is here, I just had removed it before the photo.
There are only 6 screws to be removed on the base and once these are out , you have to disconnect the LED in order to get the top off.
For this, straighten the legs and slide the connector down and clear. It may be a bit stiff, but it will come off...
The RF shielding is next and was a bit of a problem to remove. There is one screw that is used to secure the shielding to the Regulators heatsink. Unfortunately it seems they drilled a hole, but didn't put in a thread. The screw was in so tight I had to eventually cut off the head using a rotary tool in order to get the shielding off at all.
Once the motherboard was out, flip it over and find the CPU from underneath. You need Pin 15 and Pin 17. Pin 15 is for the clock speed and pin 17 is for the halt signal.
Cut the trace from Pin 15, this allows you to then add your own clock speed with a little soldering.
Next was soldering some wires to the various points. Yellow wire to Pin 15, the Processor clock speed pin, The Green wire to the original 7 Mhz clock and the pale blue wire to Pin 17, the CPU Halt signal.
While the board was over, I took the opportunity to run a +5v and GND wire from the underneath of one of the regulators.
All the wires I threaded through one of the Casing stanchion holes.
I then took my 12.5Mhz oscillator that will be used to create the overclock speed. It is a Dale XO-43B. I downloaded the datasheet HERE, but the part you need to identify what pin does what is below. Be careful to get these right, you don't want to send 5v in the wrong way. I marked mine up for when I came to solder it up. I hot glued the oscillator in place adjacent to the CPU. I was conscious of keeping the wires as short as possible so as not to introduce any problems.
Then it was a simple case of soldering all the wires to the switches. I am positioning these so that having the switches all to the left leaves the MD in standard British PAL configuration.
Pink is the 12.5Mhz clock, yellow connects to pin 15 (CPU Clock), Green to 7Mhz (native clock)
Pale blue is the CPU Halt (pin 17) and Black is GND. The third position is unconnected, when pin 17 is grounded the CPU is halted, allowing you to switch clock speed. Make note, you will still hear music playing while the system is halted. That is perfectly Ok.
Next it was the 60 Mhz and Language Mods. Find JP2 and 3 and cut the tracks inbetween them.
JP3 (White) is the 50/60Mhz jumper.
JP2 (Blue) is the language jumper.
I also connected 2 wires to the +5v (Red) and GND (Black)
I then connected them all up to the SPDT switches. When Blue is on Red (+5v) you have English, When White is on Black (GND) you have 50Mhz.
Again, I will orientate the switches so that when they are to the left they will be in standard configuration.
A quick overview of the project so far.
I then hooked her up to the TV and ran her through her paces and all seems fine. I was interested to see how she responds overclocked, but I have to say I didn't notice a huge difference. But when I get her back together again I shall give her a good old test out with my son in both speeds and video whatever difference comes up.
The MD I bought from Taj is in reasonable condition, I'll give the plastics a bit of a clean up once I'm finished. The expansion cover is here, I just had removed it before the photo.
There are only 6 screws to be removed on the base and once these are out , you have to disconnect the LED in order to get the top off.
For this, straighten the legs and slide the connector down and clear. It may be a bit stiff, but it will come off...
The RF shielding is next and was a bit of a problem to remove. There is one screw that is used to secure the shielding to the Regulators heatsink. Unfortunately it seems they drilled a hole, but didn't put in a thread. The screw was in so tight I had to eventually cut off the head using a rotary tool in order to get the shielding off at all.
Once the motherboard was out, flip it over and find the CPU from underneath. You need Pin 15 and Pin 17. Pin 15 is for the clock speed and pin 17 is for the halt signal.
Cut the trace from Pin 15, this allows you to then add your own clock speed with a little soldering.
Next was soldering some wires to the various points. Yellow wire to Pin 15, the Processor clock speed pin, The Green wire to the original 7 Mhz clock and the pale blue wire to Pin 17, the CPU Halt signal.
While the board was over, I took the opportunity to run a +5v and GND wire from the underneath of one of the regulators.
All the wires I threaded through one of the Casing stanchion holes.
I then took my 12.5Mhz oscillator that will be used to create the overclock speed. It is a Dale XO-43B. I downloaded the datasheet HERE, but the part you need to identify what pin does what is below. Be careful to get these right, you don't want to send 5v in the wrong way. I marked mine up for when I came to solder it up. I hot glued the oscillator in place adjacent to the CPU. I was conscious of keeping the wires as short as possible so as not to introduce any problems.
Then it was a simple case of soldering all the wires to the switches. I am positioning these so that having the switches all to the left leaves the MD in standard British PAL configuration.
Pink is the 12.5Mhz clock, yellow connects to pin 15 (CPU Clock), Green to 7Mhz (native clock)
Pale blue is the CPU Halt (pin 17) and Black is GND. The third position is unconnected, when pin 17 is grounded the CPU is halted, allowing you to switch clock speed. Make note, you will still hear music playing while the system is halted. That is perfectly Ok.
Next it was the 60 Mhz and Language Mods. Find JP2 and 3 and cut the tracks inbetween them.
JP3 (White) is the 50/60Mhz jumper.
JP2 (Blue) is the language jumper.
I also connected 2 wires to the +5v (Red) and GND (Black)
I then connected them all up to the SPDT switches. When Blue is on Red (+5v) you have English, When White is on Black (GND) you have 50Mhz.
Again, I will orientate the switches so that when they are to the left they will be in standard configuration.
A quick overview of the project so far.
I then hooked her up to the TV and ran her through her paces and all seems fine. I was interested to see how she responds overclocked, but I have to say I didn't notice a huge difference. But when I get her back together again I shall give her a good old test out with my son in both speeds and video whatever difference comes up.
r0jaws
Mondeo Man
With the casing washed and dried, it was time to put it all back together.
I tidied up some of the wires, and secured the switches with a dab of superglue. Usually I would use hot glue, but in order to access the motherboard again in the future, superglue is a lot easier to remove and replace. The switches are quiet secure and firmly placed, so have no chance of coming loose unless you really pummel them. I had to trim some of the RF Shielding at the rear to be able to refit it. I know it's not strictly necessary, but why not if I am able?
Next I wanted to make up some small labels to identify all the switches. I found a Sega font online and messed about with some ideas until I found a layout I was happy with.
In place, they look Ok, but I think maybe a gloss paper, or even some form of sticker would work a little better. The MD casing is a matt black plastic, so quite hard to "blend" in.
Once it as all done, I wanted to give it a good old run through. My 6 year old as more than happy to help play test. I fired up Sonic 2 and we played some 2 player using the standard 7 Mhz clock, I deliberately died with a lot of rings to appreciate just how much it slowed down. I then flipped over to the 12.5 mhz and did the same, and the difference is noticeable.
I then popped in my Everdrive to give it a further run through, and discovered that the menu screen is fine with the everdrive, but if you navigate to folders, the screen garbles and is unusable. Clearly the Everdrive doesn't like overclocked systems. However, I put it back to standard, selected my game and loaded it into memory. I then switched it off, overclocked it, and switched it on again. This way I was able to play my game selection in overclocked mode, no problem.
I'm taking it over to Zetr0's later on, hopefully I should get some video footage to demonstrate and have a bit of a laugh.
I tidied up some of the wires, and secured the switches with a dab of superglue. Usually I would use hot glue, but in order to access the motherboard again in the future, superglue is a lot easier to remove and replace. The switches are quiet secure and firmly placed, so have no chance of coming loose unless you really pummel them. I had to trim some of the RF Shielding at the rear to be able to refit it. I know it's not strictly necessary, but why not if I am able?
Next I wanted to make up some small labels to identify all the switches. I found a Sega font online and messed about with some ideas until I found a layout I was happy with.
In place, they look Ok, but I think maybe a gloss paper, or even some form of sticker would work a little better. The MD casing is a matt black plastic, so quite hard to "blend" in.
Once it as all done, I wanted to give it a good old run through. My 6 year old as more than happy to help play test. I fired up Sonic 2 and we played some 2 player using the standard 7 Mhz clock, I deliberately died with a lot of rings to appreciate just how much it slowed down. I then flipped over to the 12.5 mhz and did the same, and the difference is noticeable.
I then popped in my Everdrive to give it a further run through, and discovered that the menu screen is fine with the everdrive, but if you navigate to folders, the screen garbles and is unusable. Clearly the Everdrive doesn't like overclocked systems. However, I put it back to standard, selected my game and loaded it into memory. I then switched it off, overclocked it, and switched it on again. This way I was able to play my game selection in overclocked mode, no problem.
I'm taking it over to Zetr0's later on, hopefully I should get some video footage to demonstrate and have a bit of a laugh.
That is just awesome! I'm looking forward to seeing this handywork on hand
my son will also be thrilled as he always complains about the slowdown in sonic and gunstar.
Great work!!
Sent from my iPhone using Tapatalk
my son will also be thrilled as he always complains about the slowdown in sonic and gunstar.Great work!!
Sent from my iPhone using Tapatalk
Zetr0
Ya' Like it Retr0?
Thread update
r0jaws and I have been giving this hack-up a real test with all sorts of play - have a look
more later =D
r0jaws and I have been giving this hack-up a real test with all sorts of play - have a look
Code:
MegaDrive
GAME CPU VID NOTICE
Sonic 2 12.5MHz 50Hz 4/5
Sonic 2 12.5MHz 60Hz 5/5
Streets OR2 12.5Mhz 50Hz 4/5
Streets OR2 12.5MHz 60Hz 5/5 *[4]
Gunstar Heros 12.5Mhz 50Hz` 2/5
Gunstar Heros 12.5Mhz 60Hz` 5/5
Master System
GAME CPU VID NOTICE
Alien 3 12.5MHz 50Hz 2/5
Alien 3 12.5MHz 60Hz 2/5
32x
GAME CPU VID NOTICE
Virtua Racing 12.5MHz 50Hz 4/5 *[2]
DOOM 12.5MHz 50Hz CRASH *[3]
Compatability
[0]MegaDrive Works in all modes with 32x installed
[1]EverDrive is not completely compatible with 12.5Mhz Mod
Notes
*[0] 32x must have a Video Frequency mod 50/60Hz
*[1] Can only select Play Flash Loaded game
*[2] After 1 Lap, Game stuttered in and out of Pause Mode
*[3] Game Crashed after 2 minutes of play
*[4] It should be noted that with these modes slected this is a completely differnt game, it is both exceptionally responsive and more fun to play.more later =D
Interesting what would happen with a 60hz 32x. What do the 1/5-5/5 mean? HOW noticeable the overclock is?
A new trend may have been started here
A new trend may have been started here
Last edited:
r0jaws
Mondeo Man
Exactly that, We discussed at length how noticeable the overclock was. We would play the game in standard mode for a while to get the feel, and then restart it in 12.5 mhz.
Some games were hardly noticeable, Alien 3 on the Master system via the Everdrive for instance. But some games, like Streets of Rage 2 were very noticeable. To the point of transforming the game's playability. with 60hz and the overclock it was like a new game, responsive and highly enjoyable.
I have videos of us playing Sonic 2 in standard and overclocked mode, I'll link to them tomorrow.
Some games were hardly noticeable, Alien 3 on the Master system via the Everdrive for instance. But some games, like Streets of Rage 2 were very noticeable. To the point of transforming the game's playability. with 60hz and the overclock it was like a new game, responsive and highly enjoyable.
I have videos of us playing Sonic 2 in standard and overclocked mode, I'll link to them tomorrow.
Fantastic! There are a few others I'm looking forward to playing also - Thunderforce IV amongst them. That game has notoriously bad slowdown at times.
Job well done!
Sent from my iPhone using Tapatalk
Job well done!
Sent from my iPhone using Tapatalk
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