Resetting The BIOS

[Reloadron]

A question was posed in another forum under the heading of resetting the RTC (Real Time Clock). Todat we use terms like resetting the BIOS or resetting the CMOS. Doing this is generally done by opening the case and moving a jumper or removing the CMOS battery for a brief period of time.

The poster was looking for a way to remotely or externally reset the BIOS without opening the case. Sort of interesting, though resetting the BIOS is not something I do daily, weekly or for that matter yearly. I provided a solution using a switch mounted on the front panel and elimination the jumper on the motherboard.

The more I think about it, the more I wonder what would drive someone to frequently reset a BIOS to defaults? We are not talking about entering the BIOS at start and editing it but simply resetting it.

Can anyone see where this would be practical? I can't see a requirement and I keep thinking about it.

Ron

[screwballl]

I couldn't think of a use either unless they have a problematic mobo which if it is new should be sent back in for replacement if it has that many problems or it is user headspace errors.

[One4yu2c]

Originally Posted by Reloadron

Can anyone see where this would be practical? I can't see a requirement and I keep thinking about it.
Ron

Enthusiast overclocking, which can require tinkering with quite a few different settings in the BIOS. Same thing applies to reviewing hardware, as it comes in handy to quickly revert back to a baseline (we're big fans of manufacturers that implement reset buttons on the board, rather than playing with a jumper). Also could come in handy if experimenting with different BIOS versions, particularly beta versions.

However, in the case of the former (OCing and reviewing hardware), most current motherboards are good about resetting back to a bootable state without having to clear the CMOS should something go awry - just turn the system off for 5-10 seconds, then back on. That usually doesn't reset everything back to default, but scale back changed settings to make the system bootable again.

[screwballl]

I can see that temporarily but not a permanent button on the front. Usually once the stable OC/tinkering is done, it doesn't get messed with.

[One4yu2c]

Originally Posted by screwballl

I can see that temporarily but not a permanent button on the front. Usually once the stable OC/tinkering is done, it doesn't get messed with.

Depends - the more hardcore tinkerers frequently swap out components and update BIOS versions, which is obviously the case with reviewers too. In these cases, tinkering becomes an ongoing process. Heck, even among the one-time tinkering crowd, that process can last days, weeks, or potentially even months and include several resets. On very much a related note, it's also worth mentioning that some boards place the CMOS battery and jumper inconveniently nestled in difficult to reach places, such as under a videocard (we've griped about this in more than one mobo review). Installing a switch at the time of installing the motherboard could potentially save a headache (or three) down the line.

This isn't a feature that would have a mass mainstream market appeal, but I can see a sizable niche among enthusiasts and reviewers alike that would appreciate an easily accessible reset switch.

[Reloadron]

Thanks for the wealth of information. For what it is worth this was the basic drawings:



The switch is a simple DPDT (Double Pole Double Throw) and in reality a SPDT (Single Pole Double Throw) is all that is needed. The jumper on the motherboard would be replaced with a connector wired to the switch and a 3 pin fan connector would likely work. The switch (I suggest a mini switch) could be mounted in the front or rear of the case.

Just remember something. Looking at the switch in the picture and the toggle position. As pictured pind 2&3 would be closed. Think backwards.

If anyone has an interest as a "mod" and needs info just let me know.

Ron

[simple_inhibition]

i could definitely use something like that. im always tweaking my system and its a PITA getting to the cmos battery between my video cards.

[screwballl]

why not just a 2 post momentary switch? turn the system off, unplug the power, hold in the momentary for 5-10 seconds, plug it back in and you're done. Plus most momentary switches are small enough that there should be a hole somewhere on the back of the case to mount it (or easily drilled out to fit).

[Reloadron]

Originally Posted by screwballl

why not just a 2 post momentary switch? turn the system off, unplug the power, hold in the momentary for 5-10 seconds, plug it back in and you're done. Plus most momentary switches are small enough that there should be a hole somewhere on the back of the case to mount it (or easily drilled out to fit).

The combination I came up with and posted was one of several. Pretty much does as I said in that it does the same thing using a switch as removing and moving the jumper.

The thought of using a DPDT switch was also mentioned and using the second free set of switch contacts to feed a RED and GREEN LED. The color would indicate switch position.

The only issue I see with a single pole momentary switch (like a simple momentary push button) is the single pole is really a SPST (Single Throw) or basic momentary On / Off. We come up short a terminal. Now a push button that duplicates SPDT would work. Just hold the button and deal done.

Ron

[Capper]

A lot of newer enthusiast boards have addressed this issue by simply incorporating a BIOS that resets automatically if the board doesn't boot correctly (ASUS new BIOS comes to mind).....but still, a very good idea for those of us who tinker a lot.