A patch for reducing CPU usage by the Ultima Online Client

[Batlin]

Hi guys/girls

I present you here with a sort of tutorial on how to patch the Ultima Online Client.
To understand everything assembler knowledge is required.

Like most UO addicts will have noticed, the client uses a lot of CPU resources when it shouldn't be doing that, for example at the login screen. This annoyed me and I went inside the client to fix this "bug".

At the same time, you will learn a bit about frame-skipping done by the client (when enabled).

Attached is a PDF that explains how I did it + a ZIP with the patch applied to client version 5.0.8.3.

WARNING! Do not apply this patch to any other client out there unless you know what you are doing, this is a binary patch and modifiying the wrong bit/byte will most probably result in (random) crashes!

For version 5.0.8.3:
MD5 of the original unpatched client : fea4323aec8c71f993aad4af812ab1ed
MD5 of the client with Sleep patch applied : 78a963c0fde2bb935c14c75b688fc3f3

If demand is high enough, I could write a universal patcher that will work for other clients based on the fact they all share the same codebase.

Enjoy

[Derrick]

Great post and Mod Batlin, thanks a ton for this!

[zelda]

all i can say is wow, you have to be the smartest person ive seen to be able to do that, that is excellent work, congrats, I for one would like to see a universal patch or could you please make a patch for client 6.0.1.4, that is what I use and find it to be very stable, if not, thanks anyway, and keep on doing what you do, you are obviously very good at that..

thanks

[Dies Irae]

Great!

Could you release a patch even for client 5.0.9.1?

[Faster Ping]

whoot

[dantehu]

Is it possible that you can create a universal patch for all the cilent? I am currently using an older cilent...its not green....I think your work saves our earth and prevents global worming . Thank you in advance!

[sardino]

Oh, you are awesome. I am a computer engineering student and I know the hard work and the knowledge it takes to get where you went.
I really appreciate your guide and your patch, since that CPU usage problem is killing many computers. My laptop did shutdown last night due to over-warming.
I am sure many people will love if you do an universal patcher (myself included).
The only question I have in my mind is "Why doesn't OSI implement this?"

PS: Sorry for my english and thanks again for being such a nice guy and share your stuff with everybody

[Richardo]

that is what i was looking for years, great! But i can't say i applied it, a universal tool for it will be amazing