Identifying Atomiswave Motherboard Mod

[shelcoof]

Hey Guys

I finally had time to myself and what better way to enjoy it? Work on some projects
I was performing the Stereo Mod on my Atomiswave Systems when I stumbled upon this Motherboard that seemed like it was modified/repaired
No idea what this is and was curious if anyone else here knows?

My other Atomiswave Motherboard didn't have this extra board with wires on it

 

[XtraSmiley]

Listen, I can't tell you what this is, but DON'T cut the PURPLE wire, the PURPLE WIRE!

 

[shelcoof]

lol there are no purple wires

 

[Chrone]

The chip on there, the LVC74, is a flip-flop. I don't know the pinout for the cartridge connector or GPU so I can't say exactly what it does, but it seems to fix a memory access timing bug. Some games freeze on the AM3AGA-04 2002 motherboards that don’t have the little add-on board. Maximum Speed comes to mind but I'm sure there are others.

TP1 is ground.
TP2 is power
TP3 is the output - goes to cart connector
TP4 is the input - goes to the PowerVR2 GPU
TP6 is the clear - goes to pin1 of the amp, which is mute.


Interestingly, I've come across four motherboard variants, with the revision number corresponding to year (which doesn't necessarily match the serial number manufacture year). This is not authoritative by any means, just what I've observed. There may be other motherboard revisions floating around too.

Serial # starting with 2002 - Uses an AM3AGA-04 2002 with no mod board. Not common.



Serial # starting with 2003 - Uses an AM3AGA-04 2002 with the mod board (of this I've seen two variants, one has TP4 connected to Pin 14, the other doesn't). These are everywhere. Late production year machines may use the AM3AGA-06 2003 motherboard but I've never seen one.
.


Serial # starting with 2004 - Uses an AM3AGA-06 2003. Not common.

 

[shelcoof]

The chip on there, LVC74 is a flip-flop. I don't know the pinout for the cartridge connector or GPU so I can't say exactly what it does but it seems to fix a memory access timing bug as some games crash on the 2002 motherboards without the fix after a certain amount of time. Maximum Speed comes to mind but I'm sure there are others.

TP1 is ground.
TP2 is power
TP3 is the output - goes to cart connector
TP4 is the input - goes to the PowerVR2 GPU
TP6 is the clear - goes to pin1 of the amp, which is mute.


Interestingly, I've come across four motherboard variants, with the main revision corresponding to manufacture year (which doesn't necessarily match the serial number year). This is not authoritative by any means, just what I've observed. There may be other motherboard revisions floating around too.

Serial # starting with 2002 - Uses an AM3AGA-04 2002 with no mod board. Not common.



Serial # starting with 2003 - Uses an AM3AGA-04 2002 with the mod board (of this I've seen two variants, one has TP4 connected to Pin 14, the other doesn't). These are everywhere. Late production year machines may use the AM3AGA-06 2003 motherboard but I've never seen one.
.


Serial # starting with 2004 - Uses an AM3AGA-06 2003. Not common.

That's cool I never knew about this fix
Not that it will ever affect my enjoyment of the Atomiswave
I only have two games
Rumble Fish and Rumble Fish 2 lol

 

[djsheep]

I have 2 x 2003 motherboards here that both freeze on Dolphin Blue. it’s not a game issue as it works fine on other motherboards.

Tried everything from tweaking voltage, cleaning slots, trying different cabs / superguns, etc. — anyone know any other troubleshooting I can do or know what causes this issue? Maybe I need one of those sub boards?