These Rockman/Megaman 6 in 1 carts are more prolific now and I decided to try one off of aliexpress.
specifically: http://www.aliexpress.com/item/Megaman- ... 44e59b955c
A couple of points worth noting here is that this does not function properly on clone hardware. I have a Tri Star Super 8 unit which piggy-backs off a SNES and a few games locked up and would not proceed: MM3, MM6
On original hardware there are no issues and everything works as specified. The issue comes up when speaking about the sound processing of MM1 & 2. Whether on clone or real hardware both games have distortion and thats why I am ultimately posting with respect to this.
Here is an example of the sound troubles on a similar bootleg (pardon the 50hz speed): https://youtu.be/523qkDi1Zyw?t=53
(also, check the video in the aliexpress link for samples)
I have no background as to the cause pardon searching and seeing the notes regarding the registers [#115318
]. I also wondered if there was a conflict with the mappers and rom types not being implemented properly on cartridge.
All the same, there are cases where the sound is not distorted on MM multi-carts: https://youtu.be/NOJOX88UHTw?t=170
The issue isn't that the Rockman roms are different from the Megaman roms in the mapper department as I learned so I wondered exactly why this issue exists and what can possibly be done to remedy it. Here is further information as I found elsewhere on the exact circuit board in place on these bootlegs:
Ok on the battery side the chip says:
The text in the upper left corner says "Pocket games" which seems to be the brand name of these boards.
As you can see there is what looks like a place to connect a chip as well as a few dip points. The one on the right hand side of the battery is closed. The one next to the chip looks like a solid blob in my cruddy pic, but it's actually 3, and the top two are closed together. It's labeled "j8".
The back of the pcb:
It says UNION at the top... it appears to be the pcb manufacturer. The serial on the upper right reads: SMD157D-72 (72 most likely stands for 72 pin as there is a famicom version of this cart). The large white text in the lower right says SMD151212.
On the top left hand side there are solder points for what looks like a diode, a dip and another diode respectively labeled D1 R1 and D2. Since it's labeled R1 maybe the dip is actually a spot for a resistor?
There is a blank spot for a chip on the left labeled U6 and a chip labeled U9 below it.
The large chip to the left is labeled U3 and reads:
The square chip in the center is labeled U1 and reads:
The solder pads (for a dip) to the left of that chip are labeled 5/6K. The one below and to the right is labeled H/V (the rom order dip). The rest of the dip pads on this side of the pcb are unlabeled.
imgs: http://i.imgur.com/4htrpG1.jpg http://i.imgur.com/j45bo6b.jpg