Throttle Blaster: A hardware Turbo knob for slowing down the CPU speed (Part 1) 

Nice idea! Thumbs up.

Wait long enough and everything gets re-invented. We used commercial versions of these in the 1990's for debugging purposes. Back then it was a variable oscillator controlled by a pot that replaced the on board crystal clock source. Nice work bringing this to the Pi.

Amazing! I was a bit worried because we didn't hear from you longer than usual, but it's a pleasure to see new content from you, and this project is especially impressive! You deserve way more followers. Thank you for the video! Editing this comment to add that this makes retro gaming viable on systems where it wasn't. My socket 462 and 478 systems had ISA slots but a lot of older DOS games simply wouldn't run. Some needed patches, others still wouldn't. With this, we can have games from the early nineties to the mid 2000s running on the same hardware!

What an interesting idea I never considered. I have a function generator and can fine-tune waves, but here even a 555 timer would probably do, except for the numeric readout. An Arduino would be better. Pi is an overkill. Still, fascinating. I used to buy custom FSB chips with non-standard frequencies to tune systems, but it wasn't a live process. It still required pin manipulation between reboots. This is a completely different way of throttling the CPU, without taking the rest of the motherboard beyond spec. Truly brilliant.

Impressive ❤ This would be awesome to have in a 5.25 drive bay, with the display and knob. Maybe a task for 3d printing?

This is genuinly amazing. Well done on a great project! Your channel is great for these kinds of things!

Thank you, been collecting older games I can't easily play. Many are clock based so without something like this, it's find exact hardware...and that's getting hard to do.

That's one less TSR and a incredible increase in useability, thanks!

Wow, this is fantastic. I definitely look forward to building one of these once everything is released. This could solve so many headaches with getting games to run at the proper speeds. ESPECIALLY being able to do it on the fly like that? Insanity.

Always a pleasure to see you post.

This is a brilliant idea, well done. An idea for a future development, though I don't know if it would be possible: Integrate the Pi2040 on to an ISA card which can be addressed / controlled by the host PC. Develop some software which can be told the maximum CPU frequency, and then automatically benchmark at varying PWM values to generate a mapping of PWM values for various MHz steps. Users could then simply set the desired clock speed from the command line. It wouldn't even require a TSR.

Very cool, I think I'll make one of these, thanks! Nice to see a new video!

A literal game changing concept. Will make me feel less bad for getting an overpowered Pentium 3 system without an ISA slot.

Super cool! A must have tool. My favorite retro machine is a Slot 1 440BX with a Pentium 3 667MHz. With such device, one can tune it to any retro DOS game. I like it due to the compatibility and flexibility in using not so old infra structure (memory, PS/2 ports, AGP, PCI and ISA, ATX format, etc). Looking forward to the blueprints! And last, the Duke soundtrack is back :)

Awesome project!

This is INSANE! Great work!

You make the coolest toys!

This is so simple yet so ingenious!

Absolutely amazing project ! I would love to buy iy, or even build a retro PC from modern parts and this slow down knob !

Superb work as always!

Absolutely brilliant

great video! thanks

what an awesome project! just like its creator! keep em coming!

Fantastic!!! Using this project, virtually any CPU can be used to play speed sensitive games! Now even Duron and Celerins can be good machines to every game!

I gotta say this is a super cool project. You certainly have a unique voice, too!

fantastic video !!!

TOO COOL!!! Thanks!

This is amazing! How does it behave in regard to input devices like keyboard and mouse, with some solutions there are latency and response challenges...

This is really cool. I'd probably prefer a handful of preset speeds & a button to cycle through, rather than a continuous rotary control. This would make it almost drop-in compatible with existing turbo buttons (not sure if the switch type button would really work right) and allow more precise settings for specific games.

Now attach the Pico to the computers serial port and you can set the speed automatically from a batch file before launching a game :)

Fantastic project! This could be very easy to integrate into the right case, replacing the turbo button with the pot, and the existing display with the generic one.

oh man, this is sweet!

Awesome

Офигеннейшая идея и ОЧЕНЬ интересная реализация!

Amazing! x2 :) what a nice idea so well done ... noone ever thought of that? :D retro pcs get new area and can spread wider

Guys this great news!

As a suggestion for the calibration, you could offer a "program" menu/mode with either a rotary encoder or just some push buttons. You can even have presets and a turbo button switch input. Lots of scope for enhancements. 🙃 Edit: After watching part two it seems a lot of people thougnt the exact same, lol. Funny how that works sometimes.

God, what an amazing project! Thank you for all your efforts and for making it open source right from the get-go! I wonder how new of a CPU this strategy would work on. Socket 754 does not seem to have HOLD/STPCLK or anything similar.

5:59 for a thin wire source, the wire inside of turntable arms is the thinnest I know of (goes to the needle-pickup). If you have old/broken turntables - record-players.

That is very cool, I wonder what different cpus have the stop clock pin.

great channel.. very educational for people like me sort of starting out.. one thing id like to learn is why so many old boards just wont POST to a video output.. i have a couple of boards like that and see a lot for sale on ebay, with sellers acting like it is an "easy fix".. in my experience when a board wont POST to video output that board is DEAD and cant be resurected.. wondering if you could do a video on that taking us through the diagnostic steps, first steps etc.. anyway, keep up the great content!

Great project! Thanks for sharing! I need this. I would be really interested in testing with a locked CPU. Currently building a BX based DOS to Win98 system and would love the speed of a Tualatin CPU. Cheers!

This is an amazing project!!! It would be nice if it would be possible to actually control the speed via the dos command line, maybe sending a signal through the serial port or something. Send something through an I/O port that would be easy to code. It would be easy then to automate launching games with batch files for every specific game. When returning to dos a user could set the speed to enjoy maximum performance in DOS. Also, maybe a bit overkill but a simple CPU interposer would make this very easy to use. I don’t mind soldering a wire at all but some people might do. There’s so much potential in this it’s actually insane!!!

Wow, nice idea. It deserves many more views. Could this also be done by the ISA bus, and using the Pico - like your ISA Blaster?

Cool! I wonder if this could also be used in combination with a heat sensor to see how high one could clock a given CPU without or with passive cooling.

nice video amazing what a single wire and a pot will do.

nice

This is amazing! 👏👏👏 Would there be any chance of displaying stock system speed (say, 450MHz) upon boot, then it triggering over to the percentages when the knob is turned? Also, would there be a way to use the newer RGB 7-segment displays to implement another visual speed indicator?

This is great. It would be dope if you could push the knob for presets.

This project idea is amazing. Do you think it would be possible to allow for remote control the pico through TTL? That way I could get the DOS PC to select its own speed as part of a batch script, then change back when it's done.

I always wondered if such a thing would be possible and now you went ahead and just did it. Nice work! I assume that there's a limit to how fast you can turn STPCLK/HOLD on and off per sec, based on the Pico's capabilities. Any numbers on that?

Is the end result comparable to what the hcf command did back in the day? I know different...but not...?

Pretty cool idea! And if you remove the diplay you dont even need a microcontroller, a simple 555 timer should do the trick just fine, so it is a $0,50 circuit...

I want to try this. What's the PWM frequency?

Just had an idea - why not use a PWM electric motor controller for that? They are ready-made pieces for like 1$ a piece.

Hardware manufacturers always had to fix issues with badly coded games, it still applies today.

Too bad modern CPUs have SMD sockets. I also wonder how CPU power consumption changes. Would it be possible to run CPU like P4 with its fan completely stopped?

This may cause issues with event timers and schedulers in Windows and could therefore result in crashes? maybe... Since i did not build the circuit yet, im not sure though... Have you tried this with Windows Games as well?

Probably would benefit from logarithmic control to get finer control around the slower speeds. I'm thinking a circuit that performs this task can even be built with a 555, a similar schematic to PWM motor control applications. Probably just about any PWM implementation will work for this. Pico probably has enough lines to drive LED segments directly.

Very nice! What about overclocking lol

Great project! But does it require Pico? Can it be done with simple Atmega/Arduino board sending PWM signal?

Oh man this is cooler than the turbo button 😎 What about taking a 533mhz up to 766mhz or can only go down?

This would allow me to play Dark Ages on my Celeron 500. Doesn't produce divide errors much like my Pentium II 233 (even on a 60MHz bus - don't know why when my Pentium II/III and Celeron 300/450 and 333 do), but runs the game too fast. Problem for me is that it's the only full game I have which is truly speed sensitive.

At 4:22 your pot/ potentiometer seems a bit unstable near zero. You might need two. One pot for super fine adjustment.

what a sick idea! maybe you could make it scriptable so it can be set on a per-game basis

This would be good for flight unlimited. GT racing 97 would be good to test because the AI goes weird at a certain speed.

Can you play PC digger? That could be cool demo.

i wish this worked on socket 478

Really interesting concept, I like the idea of the 7 segment display showing a meaningful indication of CPU speed and a hardware control. This would easily allow programs written for XTs or even Wing Commander 1 or 2 to run on much more modern systems such as 486 computers. Who thought too much speed would be a problem ? I am not clear on the comment about pulling down the 486 HOLD pin as the datasheet extract indicates it is active high. I also see the CPU does not have an internal pull down resistor so there must be an external pull down. Would be great to connect to a point where there is lower risk of shorting out an adjacent CPU pin. Great idea and your proof of concept is outstanding, thanks for publishing this.

It's a little bit poetically ironic to use a Raspberry pi that is an order of magnitude faster than the original machine to make it go more slowly...