VOGONS

AOpen FC-PGA slocket - JP6 and JP7?

Topic actions

First post, by jwt27

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie

I found an AOpen FC-PGA recently and I'm now trying to see how far I can push a Celeron 733 with it.
There are seven jumpers on the slocket: JP1-5 set the CPU core voltage, JP7 selects FSB clock (1-2=auto, NC=100), and JP6 is "reserved for manufacture", according to the manual I found.
Now the JP7 description is pretty vague already, since the slocket obviously has no way of controlling the bus clock. Does this perhaps "trick" the CPU into thinking it's running at 66 or 100MHz, locking or unlocking higher multiplier settings?
And JP6 is a complete mystery to me. It was set to 1-2 when I found it, but of course I have no idea if that's the default setting. I tried 2-3 but fail to notice any difference so far.

Anyone who knows what these jumpers do?

Reply 2 of 3, by gerwin

Posted on 
User metadata
Rank l33t
Rank
l33t
jwt27 wrote:

Does this perhaps "trick" the CPU into thinking it's running at 66 or 100MHz, locking or unlocking higher multiplier settings?

I don't know that particular slotket, but a slotket cannot trick a CPU or unlock higher multiplier settings. The jumpers usually do this:

- Allow for an override of the CPU Front side bus frequency request pins. 2 jumpers. Gives either Auto, 66, 100 or 133MHz FSB, when all parts cooperate.

- Allow for an override of the CPU VID Voltage request pins. 5 jumpers.

These jumpers are very convienient, and why I prefer Slot 1 with Slotket over native Socket 370 myself. But do stick to Slotkets with a proper voltage clamp chip.

There are also jumpers which I don't fully understand: Compatibility jumpers for Coppermine 256k, Cyrix III, Dual-CPU...

--> ISA Soundcard Overview // Doom MBF 2.04 // SetMul

Reply 3 of 3, by jwt27

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie
Tetrium wrote:

Whats the part number? Have you tried googling it? And I suppose you mean slotket? Because FC-PGA just means flip chip pin grid array 😜

Yes, it's a slocket ("slocket" sounds funny so I call it that 🤣), and as far as I can tell, "FC-PGA" IS the model number. If you google "AOpen FC-PGA" you'll find the manual in the first few results. The AOpen ftp seems down at the moment but Google has cached a text-only version.

gerwin wrote:
I don't know that particular slotket, but a slotket cannot trick a CPU or unlock higher multiplier settings. The jumpers usually […]
Show full quote
jwt27 wrote:

Does this perhaps "trick" the CPU into thinking it's running at 66 or 100MHz, locking or unlocking higher multiplier settings?

I don't know that particular slotket, but a slotket cannot trick a CPU or unlock higher multiplier settings. The jumpers usually do this:
- Allow for an override of the CPU Front side bus frequency request pins, by 2 jumpers. Gives either Auto, 66, 100 or 133MHz FSB, when all parts cooperate.
- Allow for an override of the CPU VID Voltage request pins, by 5 jumpers.
These jumpers are very convienient, and why I prefer Slot 1 with Slotket over native Socket 370 myself. But do stick to Slotkets with a proper voltage clamp chip.

Then sometimes there are jumpers which I don't understand fully:
- Compatibility jumpers: Coppermine 256k, Cyrix III, Dual-CPU...

So if I get this right, JP7 would have no effect on a mainboard with jumpered FSB setting?
The reason I thought it might unlock multiplier settings is because I read about some Abit boards, which had a SEL100/66 jumper. On certain CPUs this would unlock higher multipliers, and drop the L2 cache latency from 8 to 3 clocks.

Perhaps JP6 is one of these compatibility jumpers, but then I don't get why this wouldn't be documented in the manual.

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window