Genesis 2 Overclock Kit Review! First I want to give a big thanks to Helder for sending me a couple of his kits to test out. This is an impressive mod, and an overclock for the Model 2 (and Model 1 VA7) Genesis is LONG overdue. So mad props to him! What is it? This is Helders Genesis 2 (or model 1 VA7) overclock/HALT kit. it allows overclocking of Genesis Model 2, and Model 1 VA7 Gensis systems. This is of great benefit to those who want to run PAL games on their Genesis and wish to reduce the slow-down of 50Hz mode. It's also of great benefit for getting rid of "slowdown" in games that become glitchy and slow when certain actions are performed in the game. A good example is loosing a lot of rings in any Sonic game. How does it work? To quote Helder in a personal message to me... The LTC1799 generates a square wave from 1kHz to 30Hz with the proper pin being either left floating or powered by 5v or grounded to achieve certain frequency ranges. This little device here has a simple schematic that explains the pin and frequency ranges with the correct setting http://www.ebay.com/itm/1KHz-to-33MH...YAAOxyNo9SuoJG So this chip once you have the pin configuration (has to be grounded for the home consoles since all operate on MHz) you have to tweak the resistors to get a range or a setting. What I did with mine is find the value that got me to 12mhz max and then tuned the other resistor to not drop below the normal clock or close enough to it. I had a variety of pots on hand and an oscilloscope to see the exact signals so it was a bit of trial and error and that is how I came to find the correct pot values and therefore resistor values to use in this mod. I also like how the system can be tweaked without the Halt switch if you turn it gradually and see immediate results. That's cool, but what about the modkit itself? This kit allows for overclocking a PLCC-type 68000 processor by soldering the board directly to the processor itself. Helder eliminated the need for the original clock signal by getting the LTC1799 to output the original clock speed when the potentiometer is adjusted not to have overclock enabled. The clock circuitry to all on the board that gets soldered the processor. Thus eliminating any possibility of latency issues whatsoever. The second PCB is to mount the potentiometer in the Genesis shell. There's two types of pots that can be used. Discreet (which eliminates the need to drill a hole in the shell of Genesis) and... Standard, which is a more adjustable-friendly version of the board for those that want to play around with clock speed. The kit requires that you cut the original clock trace that would normally go to pin 17 on the Motorola 68000. Helder provides the location of the clock trace on the model 2 in his PDF on how to install the mod board. I had to figure out which trace to cut on the VA7 I modded, which can be seen below. Genesis 2 clock trace to cut... For Model 1 VA7 Genesis, I used continuity check to figure out which trace to cut, but it's a bit harder to find. So I mocked up some more detailed images showing where the VA7 trace is. For example, Here is a close up board I soldered into my VA7 For more info, here's the video's I made about Helders Model 2 Variable Overclock Kit. These give you a much better idea of how to go about installing the board into the system If you have any questions or comments, please feel free to let me know! I'm sure Helder would be happy to answer any questions as well
