Question What did the small digital display with two numbers denote in older cpu cases?

[amit.rudy]

I remember that cpu cases in our schools in late 90s had a small green colored display that used to show some two digit numbers. what was the meaning behind the number? My friend once told me that it shows temperature, but i wasn't satisfied with the answer and No, i never asked the teacher. Check out the photo ---> Old CPU case . As you can see the case shown in the pic is showing "66".

 

[rgd1101]

cpu speed?

 

[USAFRet]

66MHz CPU.

Pentium, from 1995-1997 or so
https://www.pcmag.com/encyclopedia/term/49076/pentium

 

[kerberos_20]

there was also turbo button around it

 

[amit.rudy]

66MHz CPU.

Pentium, from 1995-1997 or so
https://www.pcmag.com/encyclopedia/term/49076/pentium

Seems correct! are you 100% sure?

 

[Remeca]

It showed the current CPU speed. It also worked above 100mhz, it just showed the last two digits. The purpose of the turbo button was to slow down your CPU, so software that was designed around a certain clock speed wouldn't run super fast on newer hardware.

 

[jsmithepa]

Seems correct! are you 100% sure?

My question is, WHY is this 20 years old "feature" interesting to you?

 

[amit.rudy]

My question is, WHY is this 20 years old "feature" interesting to you?

Was laying on my bed yesterday, an old pc with that display(in meme) came in my mobile, and my curiosity rose to sky to know what those numbers denote. Then i remembered that we had those pc in our school but i never got the exact answer.

 

[amit.rudy]

It showed the current CPU speed. It also worked above 100mhz, it just showed the last two digits. The purpose of the turbo button was to slow down your CPU, so software that was designed around a certain clock speed wouldn't run super fast on newer hardware.

That sounds right and im 100% satisfied with the answer.

 

[SkyNetRising]

Those digits actually were pre-programmed with jumpers or dip switches.
You could make them display, whatever you wanted.

 

[jsmithepa]

That sounds right and im 100% satisfied with the answer.

Now you are ready for JEOPARDY!

 

[InvalidError]

It showed the current CPU speed. It also worked above 100mhz, it just showed the last two digits.

Not sure I'd call those really "working" since all they do is display two patterns depending on how jumper links are setup: segment always on/off, turbo-only or normal-only. They're just dumb jumper-configurable segment displays.

 

[Remeca]

Not sure I'd call those really "working" since all they do is display two patterns depending on how jumper links are setup: segment always on/off, turbo-only or normal-only. They're just dumb jumper-configurable segment displays.

I'm not explaining how they work, just what they're indicating and why.

Edit: I see what you guys are saying now. I didn't mean it as the display was showing a live feed of the current cpu speed, whatever it was. It would just be programmed to show if the CPU was set to 33 or 66mhz. Or 166/33(would show as 66.)

 

[kerberos_20]

turbo used to to have led (around 286 era), around 386 era they improved turbo with digital display (high end pc cases), around pentium era it was just feature to brag about your cpu frequency (highest i saw was 199), this was on AT cases, with ATX cases it went away (pentium 2)

 

[InvalidError]

turbo used to to have led (around 286 era), around 386 era they improved turbo with digital display (high end pc cases), around pentium era it was just feature to brag about your cpu frequency (highest i saw was 199), this was on AT cases, with ATX cases it went away (pentium 2)

LED signs were on cheap cases a long time ago, nothing particularly high-end about it, PCs were just a whole lot more expensive in general to begin, almost nothing under $1000 new. Those things went away when CPU multipliers became software-controlled via BIOS instead of controlled via motherboard jumpers. Can't use the "turbo" button to change a jumper link on the motherboard via the case switch when the physical functionality no longer exists on newer CPUs.

 

[kerberos_20]

well that display was tied to turbo button anyway