8 ms·

I will show my age, but is there a turbo button [1] ? [1] https://en.wikipedia.org/wiki/Turbo_button https://en.wikipedia.org/wiki/Turbo_button

aroundthfur 5y ago
Funnily enough, this is how this is done on intel+linux: `echo 0 > /sys/devices/system/cpu/intel_pstate/no_turbo`
- jeroenhd 5y ago
  For just a second there I thought Intel provides the kernel some kind of backwards compatibility mode to clock down to 4.77MHz like the original turbo button.
  - jeffbee 5y ago
    There is a pin PROCHOT on all Intel processors that can be used to drop the CPU (and IGP, if equipped) into its lowest-power but still running state. It's designed to allow external voltage regulators on the board to assert that they are overloaded, but I don't see why you couldn't also wire in a turbo button there :=)
    - MikusR 5y ago
      On my Lenovo Yoga it's always on when waking from sleep. You have to connect charger, even for a short time, to drop out of PROCHOT.
gurjeet 5y ago
> Contrary to what it suggests, the "turbo" button was generally intended to let a computer run slower than the speed for which it had been designed when pressed. Damn these trickster designers and their shitty design decisions. That's exactly the opposite of what I thought it did.
- googlryas 5y ago
  Like 10 years after my 486-DX2 went into the trash after a long long life, I was reminiscing about the turbo button with a coworker, and he mentioned that he always kept his turbo button activated and that there was never a single repercussion from it!
  - mhh__ 5y ago
    Given that Turbo made it slower, why would that cause repercussions?
    - googlryas 5y ago
      Well, slower was the repercussion, but my coworker thought turbo meant faster, and was thinking along the lines of "my CPU didn't catch fire from all the extra speed I was getting"
      - coolspot 5y ago
        You misuderstood. When the turbo button is pressed, computer runs on nominal speed. When turbo button is un-pressed, computer would run on half of nominal speed. So, unpressed button makes computer slower, not pressed one. Source: actually used the button on my 386 SX 20/40 MHz
        p_l 5y ago
        Yep. I always had the turbo button pressed, except for occasionally deciding to play Test Drive 3 at speeds lower than "light speed". It was the one game I had that didn't calibrate the delay loop properly and my 486 was waaay too fast for normal playing - something that I didn't know so I learnt to play a very twitchy version...
        googlryas 5y ago
        Sorry, but I think you're confused in the same manner my coworker was. Activating the turbo button decreases the speed of your computer. Maybe yours operated differently, but everything I can find about turbo buttons on the internet indicates that they operated as I remember them - your computer gets slower when you turn the button on. I specifically remember playing certain DOS games where, if I didn't activate the turbo button, the entire game would speed through at what felt like double or triple speed. From wikipedia on Turbo button: > On IBM PC compatible computers, the turbo button selects one of two run states: *the default normal speed or a reduced "turbo" speed*. It was relatively common on computers using the Intel 80286,[1] Intel 80386 and Intel 80486 processors,[2] from the mid 1980s to mid 1990s. The name is inspired by turbocharger, a device which increases an engine's power and efficiency. *Contrary to what it suggests, the "turbo" button was generally intended to let a computer run slower than the speed for which it had been designed when pressed.*[3] https://en.wikipedia.org/wiki/Turbo_button https://en.wikipedia.org/wiki/Turbo_button
deleted 5y ago
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danaris 5y ago
One of my father's computers had one of these. It literally did nothing except change an LED readout on the case from saying "16" to saying "166".
- matja 5y ago
  I remember setting those 7-segment LEDs up on my first PC build. On the motherboard there was a jumper which took the input from the turbo switch. To provide feedback to the user, some cases ran a wire from the turbo switch to a bi-color LED on the front of the case as well as to the motherboard to control the turbo state. On fancier cases they had multiple seven-segment LEDs which had a multi-state jumper for each segment, which decided to light that segment depending if the switch was on or off (example: http://www.minuszerodegrees.net/led_speed_display/LED%20display%20-%20GK-01.jpg http://www.minuszerodegrees.net/led_speed_display/LED%20disp...), so you could display either the two different clock frequencies, or a "HI"/"LO" message, or anything you wanted. And connecting that switch input to the motherboard wasn't necessary for the LED to change, so I guess that is how your father's was setup :)

aroundthfur 5y ago

Funnily enough, this is how this is done on intel+linux: `echo 0 > /sys/devices/system/cpu/intel_pstate/no_turbo`

jeroenhd 5y ago
For just a second there I thought Intel provides the kernel some kind of backwards compatibility mode to clock down to 4.77MHz like the original turbo button.
- jeffbee 5y ago
  There is a pin PROCHOT on all Intel processors that can be used to drop the CPU (and IGP, if equipped) into its lowest-power but still running state. It's designed to allow external voltage regulators on the board to assert that they are overloaded, but I don't see why you couldn't also wire in a turbo button there :=)
  - MikusR 5y ago
    On my Lenovo Yoga it's always on when waking from sleep. You have to connect charger, even for a short time, to drop out of PROCHOT.

gurjeet 5y ago

> Contrary to what it suggests, the "turbo" button was generally intended to let a computer run slower than the speed for which it had been designed when pressed. Damn these trickster designers and their shitty design decisions. That's exactly the opposite of what I thought it did.

googlryas 5y ago
Like 10 years after my 486-DX2 went into the trash after a long long life, I was reminiscing about the turbo button with a coworker, and he mentioned that he always kept his turbo button activated and that there was never a single repercussion from it!
- mhh__ 5y ago
  Given that Turbo made it slower, why would that cause repercussions?
  - googlryas 5y ago
    Well, slower was the repercussion, but my coworker thought turbo meant faster, and was thinking along the lines of "my CPU didn't catch fire from all the extra speed I was getting"
    - coolspot 5y ago
      You misuderstood. When the turbo button is pressed, computer runs on nominal speed. When turbo button is un-pressed, computer would run on half of nominal speed. So, unpressed button makes computer slower, not pressed one. Source: actually used the button on my 386 SX 20/40 MHz
      - p_l 5y ago
        Yep. I always had the turbo button pressed, except for occasionally deciding to play Test Drive 3 at speeds lower than "light speed". It was the one game I had that didn't calibrate the delay loop properly and my 486 was waaay too fast for normal playing - something that I didn't know so I learnt to play a very twitchy version...
      - googlryas 5y ago
        Sorry, but I think you're confused in the same manner my coworker was. Activating the turbo button decreases the speed of your computer. Maybe yours operated differently, but everything I can find about turbo buttons on the internet indicates that they operated as I remember them - your computer gets slower when you turn the button on. I specifically remember playing certain DOS games where, if I didn't activate the turbo button, the entire game would speed through at what felt like double or triple speed. From wikipedia on Turbo button: > On IBM PC compatible computers, the turbo button selects one of two run states: *the default normal speed or a reduced "turbo" speed*. It was relatively common on computers using the Intel 80286,[1] Intel 80386 and Intel 80486 processors,[2] from the mid 1980s to mid 1990s. The name is inspired by turbocharger, a device which increases an engine's power and efficiency. *Contrary to what it suggests, the "turbo" button was generally intended to let a computer run slower than the speed for which it had been designed when pressed.*[3] https://en.wikipedia.org/wiki/Turbo_button https://en.wikipedia.org/wiki/Turbo_button

deleted 5y ago

[deleted]

danaris 5y ago

One of my father's computers had one of these. It literally did nothing except change an LED readout on the case from saying "16" to saying "166".

matja 5y ago
I remember setting those 7-segment LEDs up on my first PC build. On the motherboard there was a jumper which took the input from the turbo switch. To provide feedback to the user, some cases ran a wire from the turbo switch to a bi-color LED on the front of the case as well as to the motherboard to control the turbo state. On fancier cases they had multiple seven-segment LEDs which had a multi-state jumper for each segment, which decided to light that segment depending if the switch was on or off (example: http://www.minuszerodegrees.net/led_speed_display/LED%20display%20-%20GK-01.jpg http://www.minuszerodegrees.net/led_speed_display/LED%20disp...), so you could display either the two different clock frequencies, or a "HI"/"LO" message, or anything you wanted. And connecting that switch input to the motherboard wasn't necessary for the LED to change, so I guess that is how your father's was setup :)