Emulate old PC?

Question

I'm writing a Flash game, pretty intensive on CPU.

Besides optimizing it a lot, I would like to be able to play it as players on slow PC's will, because I have a good CPU and I would like to make it also playable on bad CPU's

First I thought that virtualization would help, but I've tried vmware player with an ubunto image and I can't find anywhere how to do this.

Buying an old PC is not an option, as I prefer not having machines around only for this.

What I need is something like a software underclocker, or a virtual machine where I can specify low specs for CPU and RAM.

Anyone know how to do this?

Thanks!

Answer 1

Buy another OLD PC.

Old PCs are so cheap, the cost of an old box should be a heck of lot cheaper than the time it will take you to figure out how to do this.

Answer 2

Modern "virtual PC" software relies on virtualization support features in the host CPU, and that the virtual machine has the same instruction set as the host. So programs are executed directly, with "traps" stopping execution when the host needs to do something behind the scenes to maintain the virtualization. This would not help you.

If you're on Linux, you could try running the program in Valgrind, that provides a 10X slowdown in most cases. :) It's not by design though, so it's not a long-term solution.

Answer 3

there are CPU throttling utilities that slow the cpu down, not entirely sure how much they'd help. Heres a link to one I just found with a quick google.

Answer 4

Microsoft Virtual PC is VM software that allows you to determine the speed of the CPU, RAM settings, and Video Card settings for each virtual Machine you create. From the website:

Configurability - After installing Virtual PC, you can configure it to suit your requirements. Virtual PC has a number of settings that control how the product interacts with the physical computer, allocates resources, and so on.

I've used it to emulate a 400mhz PC with 128 Megs of RAM before.

Edit:

A Virtual Machine on Virtual PC will be slower than your host PC. I remember in VPC 2004, it would even say what the mHz speed it was virtualising was. That is no longer in Virtual PC 2007, but some digging shows that the Microsoft guys have addressed this very issue.

From their website's blog (given that it may disappear one day):

Well - maybe an emulation solution is better for your needs. Or, maybe you need to invest in some older hardware. Or - you could pursue the use of 'slow down' software inside of the virtual machine. Some programs that I have used with varying levels of success include:

• For DOS:
  • SlowDown or MoSlo
• For Windows:
  • Turbo

One final comment on this topic - some people have noticed that some older DOS programs that are known to crash on fast hardware actually run perfectly inside of Virtual PC / Virtual Server. The reason for this is that a long time ago in Virtual PC development, we put in some code to detect the problematic routines in some common DOS libraries (checkout this for an example reference) and to patch these binaries 'on the fly' so that they would run correctly inside of the virtual machine.

I hope that helps.

Answer 5

Just go to garage sales/look in the newspaper/check thrift stores/etc. for an old machine. You should be able to pick up like a PIII 450 for cheap.

Answer 6

Well, buying an old PC is not an option, as I prefer not having machines around only for this.

I've downloaded microsoft virtual PC, but I can't seem to find where to adjust CPU settings. Ok with RAM, but CPU throttling is not available!

The option killersponge mentioned: i've downloaded the utility, but I'm on Vista x64 and it doesn't work :(

Answer 7

I used a program called CPU Killer to play commandos behind enemy lines on my modern pc. The speed of that game is proportional to the speed of your computer. It's designed for 200mhz so running it on 3GHz without cpu-killer was impossible. :D

Answer 8

Press the "turbo" button off on the front of your case.

Answer 9

Install Norton Antivirus

Turns any modern cpu into a 400MHz

Answer 10

You can try using CPU Killer

http://www.cpukiller.com/

Answer 11

Throttle your program to a fixed framerate using a timer. That way you give CPU time you don't need back to the operating system. The human eye can't do much better than 25 fps anyways. Setting a fixed framerate of 50/60 fps should be more than enough for a Flash game.

Answer 12

DOSBOX emulates an old PC. It is intended to play old PC games. Some of these games must not run too fast and often does not work at all on modern hardware.