|HP Pavilion a4316f Desktop PC - support|
Motherboard Specifications, M2N78-LA (Violet6)
* Motherboard manufacturer's name: Pegatron M2N78-LA
* HP/Compaq name: Violet6-GL8E
"...Pegatron is a division within ASUS. ASUS is spinning-off Pegatron completely and will be a separate company (partly owned by ASUS) that does the actual manufacturing. ASUS' branding will still go on the products that are marketed by ASUS, but not the products that Pegatron supplies to OEMs such as HP."
I see your mboard has no legacy floppy data header. Bogus.
I have never come across an internal USB connected or SATA connected floppy drive; the former might exist; I very much doubt that the latter exists. There is no such thing as a cable or adapter that connects a legacy floppy drive directly wired to a USB port connection - there has to be additional circuitry in between the two.
You could use an external USB connected floppy drive, but they cost at least $40 or so.
The F USB headers are probably the same as on Asus mboards - for two USB ports - and wired up the same way as for Asus mboards.
F probably stands for Front ?
Pin 1 is on the 4 pin side, on the other end from where the pin is missing.
In that 4 pin row, from pin 1, +5v, Data 1 -, Data 1 +, Ground
In the 5 pin row
The pin beside pin 1 is +5v, Data 2 -, Data 2 +, Ground, no connection to the fifth pin.
Each row is for one USB port.
You have two F USB headers, not four.
Use something to magnify the printing on the mboard if you need to.
NOTE that there is a F 1394 header - it has the identical pin layout as the F USB headers, upside down - DO NOT connect USB port wiring to that, or firewire port wiring to the USB headers - doing so will damage whatever you plug into the mis-wired ports in a very short time, and can damage mboard circuits as well.