There probably is a way to wire a switch to it, but Gateway probably opted not to, perhaps.

Tried pressing CTRL+ALT+KP MINUS all at once?

Thanks for the replies.

Yeah, I tried the CTRL+ALT+KP MINUS combo, but didn't have any luck. It looks like I may have to resort to changing mobo jumpers internally (ughh!) if I want to reduce speed.

Or, I did notice in the system's (crappy) Phoenix BIOS that there are options for reducing the "Standby State" processor speed and then eliminating the "wake-up" options so that it might run at the reduced speed until the BIOS settings were changed again.

I haven't tried this last line of thought yet, though, since I want to archive the current (stable) BIOS settings before I start doing changes which can sometimes have "unexpected" results.

I'm having the same troubles with my Commodore PC-50 386SX PC....still banging my head into the wall since I haven't figured out how to change the speed on it either
Damn proprietary motherboards! 😵

digitaldoofus wrote:

It looks like I may have to resort to changing mobo jumpers internally (ughh!) if I want to reduce speed.

Not necessarily...

There are several utilities that will disable the 486's internal cache (ICD/ICE, 486CACHE, etc.), effectively slowing your system to 386-ish speeds, and allowing for games like Wing Commander and Ultima VII (Part One) to run properly.

It looks like I'm having some success by changing the "Standby" cpu speed in my 486's Phoenix BIOS, and then disabling the keyboard and mouse wake-up options.

The BIOS allows for 1/4, 1/8, and 1/16 cpu slow-down in its Standby states, so hopefully this will make very old speed-sensitive games playable. I have already tested it on the old DOS game HEATWAVE and it did indeed slow it down (in fact, to a slideshow level at max slowdown).

Although not as handy as pressing a Turbo button, it provides multiple levels of slowdown -- and it sure beats re-jumpering the mobo!

(If needed for some games, I will also consider using a cache-disabling program as also suggested in this thread.)

digitaldoofus wrote:

It looks like I'm having some success by changing the "Standby" cpu speed in my 486's Phoenix BIOS, and then disabling the keybo […]
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It looks like I'm having some success by changing the "Standby" cpu speed in my 486's Phoenix BIOS, and then disabling the keyboard and mouse wake-up options.

The BIOS allows for 1/4, 1/8, and 1/16 cpu slow-down in its Standby states, so hopefully this will make very old speed-sensitive games playable. I have already tested it on the old DOS game HEATWAVE and it did indeed slow it down (in fact, to a slideshow level at max slowdown).

Although not as handy as pressing a Turbo button, it provides multiple levels of slowdown -- and it sure beats re-jumpering the mobo!

(If needed for some games, I will also consider using a cache-disabling program as also suggested in this thread.)

Nice feature you got there....almost the same feature I have on my ECS UM4980 socket 3 motherboard where I can change the slowdown in 16 steps.
It also has a phoenix bios.

Amigaz wrote:

Tried pressing CTRL+ALT+KP MINUS all at once?

http://www.oldskool.org/guides/oldonnew/friendlyboxes suggests CTRL+ALT+KP SLASH , though admittedly that's not a Gateway.

That combo key press doesn't work on my Gateway (but thanks for the suggestion). 😐