PART 2
The story of v4
Aug 27 2013, the initial concept was conceived for how to approach the next generation MEGAdrive ( now known as v4 ). This version was actually in development months before v2. Thru all the design changes and different approaches during the v4 development, a few of the previously scrapped ideas lead to the creation of v2 and then the improved v3.
v4 is by far the most complexed design I have created for the MEGAdrive project. The complexity of this design presented two issues:
1. finding a user friendly method of installation...
2. making a user friendly plug n play design that will actually fit within the limited space available...
There must have been over 20 design revisions during this development with most of the revisions requiring a complete start over from the beginning. I found myself continuously unsatisfied with the end results. It appeared as if the closer i came to achieving a great fit, the harder the installation became. The greatest challenge during this development was to maintain a user friendly design. What is known and has been a constant goal was to position the modchip between the drivecage and the drive board like this:
The advantage to this design is access to the mainboard would not be any different for how we typically access the mainboard during routine cleaning or inspection of the mainboard, fan, vents, etc etc. About 20 screws are removed from the drivecage. Then the drivecage + dvd drive are lifted off as one piece. This means the modchip will also be removed easily without having to touch it at all, thus minimizing and potential risk of damage . The modded drive could also be swapped into any other mainboard. This would allow a user friendly design since access to the driveboard itself is a very very rare occurrence. Other than adjusting the laser pot, what other reason is there to access the dvd driveboard? With this design in mind, progress moved forward to discover and create the solution.
It all started out from an idea presented by emu_kidid. His idea was to remove the drive connector from the dvd drive board. That connector would be soldered onto a PCB with an FFC connector for direct connection to the HOST side of the modchip and a second FFC connector audiostreaming data.
The drive board would have second PCB with an FFC connector for direct connection to the DVD side of the modchip and a second FFC connector for audio streaming as show in this beta development pic
While emu_kidid's idea was great, it turns out there were physical limitations which would prevent this design from moving forward due to the increased height the DVD drive would have to be lifted from the "drive cage." Using washers, the drive can be lifted maximum of about 1mm (if i remember correctly). Lifting the drive any higher would present issues screwing on the top half of the GC case back on normally. The FFC connectors would be the sole components defeating this design. To put this in perspective here is a crappy drawing:
Due to these clearance issues, this design direction was scrapped but the initial input alone from emu_kidid implanted in my mind a plethora of possibilities and directions to investigate. The initial design attempt created a great foundation of understanding for identifying the limitations of designing an acceptable solution. Since the FFC connectors could not be used with this design, the need to bypass the connectors was required. While looking at the GC controller board, it has an FFC cable directly soldered onto it. Why not create a design similar which would bypass the FFC connector? That direction could be possible but it would also require soldering 5v to the driveboard since the modchip is only capable of passing 3v. I wanted to eliminate the need for soldering as much as possible for anyone who purchased this design. I've come to understand soldering is an evil word and some people will simply turn away and wait for something that requires no soldering. SDML comes to mind. People who are typically nervous about turning a screwdriver, opening a GC, and performing soldering lean toward SDML as an acceptable solution since there is no potential for damage. While i have heard SDML is great, it does come with some limitations. Later on i will discuss a potential MEGAdrive vs SDML challenge.
...to be continued...
