There are 20-to-24 pin adapters for ATX PSUs available.
I'd be more concerned about the ability of the M1ATX to provide the power necessary for that board.
I am using a mini-ITX Via C3 mobo with a M1 ATX PSU
Now with the new Intel D201GLY2 available for cheap, I am getting tempted to replace the board
However, the M1 ATX only has a 20 pins power supply cable (and not the 4 pin CPU power cable)
Can i use the M1 ATX to power the D201GLY2 using a molex to 4 pin converter or something similar?
Here are some links that have a bit of information about powering the D201GLY2
I honestly tought the M1 should have been able to power this board until I came across this:
I got it from this website.NOTE: Do not use M1-ATX as the D201GLY draws V(core) power from the 12V rail, therefore the M1-ATX might not work well despite the fact that it is a 90watt PSU.
So you probably gonna need a bigger PSU. As DarquePervert said. Many 20 to 24 pin adapters are available to use then.
EDIT: Wile I was googling, TruckinMP3 seem to have beaten me to it...
The M1-ATX specs says 2A on the 12V rail which equates to a peak available 24W on the 12V rail
GIven the fact that the entire system draws around 20-30W, shouldn't the M1-ATX 12V rail be able to power the CPU?
it powers them just fine, I've got an M1-ATX powering mine, most of the other things I'm running are CF Flash adapter + USB 2.5" HDD and cdrom are 5v, so you'll be fine, just solder a 4-pin connector to one of the floppy connectors