10 mhz to 12 mhz
- Thread starter nonosto
- Start date
PascalP
Legendary
Just swap the crystal, that’s it
Pretty easy swap. I’ve done it for myself and a few others here.
http://the-artcade.blogspot.com/2018/06/cps1-dash-kick-harness-upgrade.html
http://the-artcade.blogspot.com/2018/06/cps1-dash-kick-harness-upgrade.html
pacoarcade
Professional
Motorola 68000 seems to support 20% overclock pretty well. In Sunset Riders boards it's common to see 12MHz rated M68000 running at 16MHz without any issue.
One pin is attached to a ground plane so I wouldn't try to desolder the old xtal without a good desoldering tool. I'd also suggest to use a proper socket just in case you need to swap it again in the future.
One pin is attached to a ground plane so I wouldn't try to desolder the old xtal without a good desoldering tool. I'd also suggest to use a proper socket just in case you need to swap it again in the future.
A
Apocalypse
A DIP14 socket with cut legs also does the trick (but doesn't look as nice).
pacoarcade
Professional
I prefer the proper socket since in my experience it grabs the xtal better compared with the DIP14 machine tooled socket I used. It also looks way neater 
So long as you know the donor crystal is good! I assume that cps2 A board is dead, because if it isn’t please don’t kill it. Just buy a new crystal, they’re cheap.
I don’t have measurements on me but I think this is the right size: https://www.digikey.com/product-detail/en/ecs-inc/ECS-100A-120/X126-ND/79217 regardless I’m sure you can find a new crystal.
I don’t have measurements on me but I think this is the right size: https://www.digikey.com/product-detail/en/ecs-inc/ECS-100A-120/X126-ND/79217 regardless I’m sure you can find a new crystal.
ShootTheCore
Legendary
Your "Dash" donor is already running 12 mhz.
A
Apocalypse
I think the dash is faulty and he wants to swap the crystal over.
pacoarcade
Professional
I tried an oscillator from Farnell and it didn't work. This one was recommended in the other thread and I can confirm it worked fine: https://www.ebay.es/itm/401396958941
This is the silkscreen text under that xtal in that board:
711A OR
711S4 OR 711J
10.00MHZ
This is the silkscreen text under that xtal in that board:
711A OR
711S4 OR 711J
10.00MHZ
yes the donor is completely died.
A
Apocalypse
But to answer your question, yes it'll work.
I noticed that the part number of both boards is the same 89626A-4
Which (i thought) makes them both 12mhz boards?
(But the receiver board is clearly 10mhz, did capcom make 10mhz 89626A-4 boards or was ii modified in the past maybe?)
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A
Apocalypse
Probably, the CPU is 10Mhz. The only reason to swap the 12Mhz crystal to 10 would be to have correct speed of play on some older games. But for that you don't need to replace the CPU (you just leave the 12Mhz 68000 running "underclocked" at 10Mhz).
pacoarcade
Professional
The 10MHz board comes with a 10MHz xtal and a 10MHz rated Motorola 68000 CPU. The DASH 12MHz board comes with a 12MHz xtal and a 12MHz rated Motorola 68000.
Swapping the xtal to 12MHz will make the 10MHz board work exactly as a "pure" 12MHz board. The CPU would run at 20% overclock, though, but it seems to support it perfectly well.
If you put a 10MHz xtal to a 12MHz board it will work like a 10MHz board without any problem.
A
Apocalypse
I've also seen 10Mhz mobos with 12Mhz CPUs (I guess they used what was available and cheap at the time of manufacturing).
@nonosto just swap the crystal and you'll be fine. Of course you can also replace the CPU but those J legs are messy...