Mac OS changed substantially with "OS X". If the system is running OS X 10.4 or earlier, then it can run older Macintosh applications (i.e. those that required OS 9 or earlier) in the "Classic" environment. Support for Classic was dropped in 10.5, which is the last version that G5 can use; on systems with 10.5, you have to use an emulator – in which case you're not much better off than running the same emulator in Windows.
http://www.everymac.com/systems/apple/powerma … -9-windows.html
https://en.wikipedia.org/wiki/List_of_macOS_c … ponents#Classic

For many games like Phantasmagoria, Shadow Warrior, and Quake, you are probably much better off just using the Windows (or DOS) version.

jnjg25 wrote:

so i found a working power mac in the alley i have some mac games, quake, shadow warrior, sim city, phantasmagoria will these game swork on my power mac G5 i know very little of mac os

Check your games. They should specify which system they can run on.
Basically any new games designed for intel macs won't work.
Old games designed for pre-OSX powerpc systems can run in classic environment in OSX 10.0-10.4.
Older games written for 68k macs can run in emulators.
Games designed for powerpc OSX should work.
You can use virtual machines to run DOS or windows or even other OSes, of course, but there is severe speed penalty without 3D support and potential incompatibility with DOS audio.

Jorpho wrote:

Mac OS changed substantially with "OS X". If the system is running OS X 10.4 or earlier, then it can run older Macintosh applic […]
Show full quote

Mac OS changed substantially with "OS X". If the system is running OS X 10.4 or earlier, then it can run older Macintosh applications (i.e. those that required OS 9 or earlier) in the "Classic" environment. Support for Classic was dropped in 10.5, which is the last version that G5 can use; on systems with 10.5, you have to use an emulator – in which case you're not much better off than running the same emulator in Windows.
http://www.everymac.com/systems/apple/powerma … -9-windows.html
https://en.wikipedia.org/wiki/List_of_macOS_c … ponents#Classic

For many games like Phantasmagoria, Shadow Warrior, and Quake, you are probably much better off just using the Windows (or DOS) version.

So if im understanding you correctly you're saying the oldest version of mac os that the g5 supports, is to new for the mac games i have?

It depends on your G5 model, I guess.. But generally speaking, Tiger does also run on G5s.
I think there even was some sort of special edition of 10.4 for that kind of Mac (incl. classic environment).
But I'm speaking under correction, I'm just a G3 and G4 owner right now. 😅

You should be fine with Tiger unless the games require 10.5 but I would check the system over and clean it before putting it to use, I like older PPC macs as they do run a lot that isn't compatible with Intel macs. G5 systems are special in some ways that they are so different from earlier systems while being a very different breed from Intel macs.

jnjg25 wrote:

So if im understanding you correctly you're saying the oldest version of mac os that the g5 supports, is to new for the mac games i have?

No... As suggested, OS X 10.4, "Tiger", should run on your G5. http://www.everymac.com/systems/by_capability … -supported.html actually suggests that 10.3.8 might work, but I wouldn't know of any particular reason to use that instead.

I sure wouldn't mind having a G5. I don't know what I'd do with it, but it would probably be a lot more useful than my Powermac 6100.

Jorpho wrote:

jnjg25 wrote:

So if im understanding you correctly you're saying the oldest version of mac os that the g5 supports, is to new for the mac games i have?

No... As suggested, OS X 10.4, "Tiger", should run on your G5. http://www.everymac.com/systems/by_capability … -supported.html actually suggests that 10.3.8 might work, but I wouldn't know of any particular reason to use that instead.

I sure wouldn't mind having a G5. I don't know what I'd do with it, but it would probably be a lot more useful than my Powermac 6100.

I think you meant - http://www.everymac.com/systems/by_capability … -supported.html - and 10.5.8 😉

I have 10.5.8 on a maxed out 1.42GHz MDD and it stutters a little in basic tasks. Early G5s, the 1.6GHz especially, were supposedly slower than some G4s so an early G5 might benefit from an older OSX. If the OP has a 1.8GHz Dual Processor or better 10.5.8 might be a good fit.

JidaiGeki wrote:

I think you meant - http://www.everymac.com/systems/by_capability … -supported.html - and 10.5.8 😉

I have 10.5.8 on a maxed out 1.42GHz MDD and it stutters a little in basic tasks. Early G5s, the 1.6GHz especially, were supposedly slower than some G4s so an early G5 might benefit from an older OSX. If the OP has a 1.8GHz Dual Processor or better 10.5.8 might be a good fit.

I think Jorpho meant to say 10.4 because 10.5 dropped the support for classic environment which is bad for retro gaming.

lazibayer wrote:

JidaiGeki wrote:

I think you meant - http://www.everymac.com/systems/by_capability … -supported.html - and 10.5.8 😉

I have 10.5.8 on a maxed out 1.42GHz MDD and it stutters a little in basic tasks. Early G5s, the 1.6GHz especially, were supposedly slower than some G4s so an early G5 might benefit from an older OSX. If the OP has a 1.8GHz Dual Processor or better 10.5.8 might be a good fit.

I think Jorpho meant to say 10.4 because 10.5 dropped the support for classic environment which is bad for retro gaming.

I thought J was pointing out the latest OS officially supported but made a typo 😉

Fair point re 10.4, with 10.5.8 the OP could try SheepShaver I guess but that seems comparatively tricky to set up.

Yes, classic environment is REALLY bad for retro-gaming.
The Integration of the Classic Environment is better in 10.3.9 than in 10.4, but it has LOTS of issues.
Sometimes the mouse is not working, sometimes the keyboard. Videos are not played korrect, the sound is corrupted etc.
Some not much demanding games do work like Tombraider 1-3 but they require deactivating the videos and using "macglide".
Other games like Rune/Unreal/UT99 have "lagging" issues. (The OSX Versions (Unreal/UT99) have no music...it's argh!

Do to my experiences (retro) gamers should not use the classic environment.

OS8/9 machines have by far more good games 😀

I wonder if a hypervisor is available here?

JidaiGeki wrote:

Fair point re 10.4, with 10.5.8 the OP could try SheepShaver I guess but that seems comparatively tricky to set up.

Like I said – if you're going to run Sheepshaver, there's no reason to stick with the G5 at all. I think the OS X port of Sheepshaver might be a little more up-to-date than the Windows port, but the latest OS X port won't run on a G5 anyway. As of late there has been some progress in running OS 9 in QEMU, but the same applies there.

dr.zeissler wrote:

Yes, classic environment is REALLY bad for retro-gaming.

I did not know it was that bad. I suppose that means that a G4 is the way to go, since that can apparently still boot OS 9.
http://www.everymac.com/systems/by_capability … -9-classic.html

Jorpho wrote:

I did not know it was that bad. I suppose that means that a G4 is the way to go, since that can apparently still boot OS 9.
http://www.everymac.com/systems/by_capability … -9-classic.html

Except the FW800 model.

If you like a noisy machine, then go for a PM-G4, they were never silent.
I stick to my G4 Mini for the early OSX games up to 10.3.9. and a view os9 titles that work OK in classic
Perhaps Classic was better integrated in the earlier OSX-Versions like 10.1.x
My G4-Mini starts with 10.3.7, the G4-Mini with 64MB Vram starts with 10.4.x

For native OS9 and below I still have a PM-G4 witch is very loud, beside that I have a G3 B&W witch
is relativly silent if you don't put a V3-3000-PCI in it and beside that I still have my PM7300 with
G3-400 upgrade card an an apple pentium166 card as well. This PM7300 is my favorite machine,
since I did not get a doscard from from orange for my G3 B&W. Beside of that I still have my
iMac 15" flat panel, but it has only a GF2-mx. I selled my two cubes a long time ago.

dr.zeissler wrote:

If you like a noisy machine, then go for a PM-G4, they were never silent. I stick to my G4 Mini for the early OSX games up to 10 […]
Show full quote

If you like a noisy machine, then go for a PM-G4, they were never silent.
I stick to my G4 Mini for the early OSX games up to 10.3.9. and a view os9 titles that work OK in classic
Perhaps Classic was better integrated in the earlier OSX-Versions like 10.1.x
My G4-Mini starts with 10.3.7, the G4-Mini with 64MB Vram starts with 10.4.x

For native OS9 and below I still have a PM-G4 witch is very loud, beside that I have a G3 B&W witch
is relativly silent if you don't put a V3-3000-PCI in it and beside that I still have my PM7300 with
G3-400 upgrade card an an apple pentium166 card as well. This PM7300 is my favorite machine,
since I did not get a doscard from from orange for my G3 B&W. Beside of that I still have my
iMac 15" flat panel, but it has only a GF2-mx. I selled my two cubes a long time ago.

I started with a G4 MDD 867MHz and any simple task would trigger its loud fan. Later I swapped the CPU/mobo with 1.42GHz DP/FW800 but kept the old heatsink and man, the fan went full power ever so easily. Recently I found a FW800 1.42GHz DP in a dumpster and surprisingly it's much quieter than the hybrid I built. I monitored the temperature readings in iStatPro and the real FW800 has much better CPU temperature control. I guess the copper heatsink helped a lot.

As people already hinted, someone can't go wrong with Tiger (incl. OS 9 as a part of it).

It's the most compatible, spanning about four processor generations : G3 ,G4, G5 and x86.
Perhaps even more, if we do include the older 603/604 processsors (see this thread).

There's even a theme available to bring back the more consistent Aqua design from Jaguar (incl. transparency and pinstripes)..

-> Just be careful with flashed graphics cards, Tiger got some of its internals changed after 10.2 that could cause a few glitches. 😉
See this thread : https://forums.macrumors.com/threads/help-10- … sappear.205437/
It's not a big thing, though. I solved that by updating my card's firmware.

In terms of networking, Jaguar/Panther were probably the most compatible (see this thread).

lazibayer wrote:

Jorpho wrote:

I did not know it was that bad. I suppose that means that a G4 is the way to go, since that can apparently still boot OS 9.
http://www.everymac.com/systems/by_capability … -9-classic.html

Except the FW800 model.

True, but people are working on stuff like that. 😀
https://www.thinkclassic.org/viewtopic.php?id=46

dr.zeissler wrote:

OS8/9 machines have by far more good games 😀

Yup, that''s for sure. System 7 machines were also nice.
They were around when multi media started to get popular.

Jo22 wrote:

True, but people are working on stuff like that. 😀
https://www.thinkclassic.org/viewtopic.php?id=46

Thanks for the info. I guess the more we discuss the more likely OP would trade the new found G5 for a G4 🤣

lazibayer wrote:

Thanks for the info. I guess the more we discuss the more likely OP would trade the new found G5 for a G4 🤣

Yeah, guess that's right! Haha. ^^
I spent myself a lot of time and some money to fix my G4 :

It was in bad shape when I got it. So I replaced the optical drive, memory, fans - cleaned the case, etc.
Heck, I even upgraded the CPU! That wasn't easy, but I got it done. It's now a dual-processor machine, with one Gibibyte of RAM. 😁

The graphics card is a Geforce 2, because it works so nicely on both OS X and 9 (except for its lack of 16:9 support in OS 9).
The only drawback is the lack of hardware-assisted Core Image. So less graphics effects on Tiger..

But I can't complain. It's now running most recent stuff, like Celestia or Lazarus.
I also got the Arduino IDE working, so I can use it for something useful.
And with some patience, I'm also able to run iMovie HD now.

..

Anyway, a G5 isn't bad, though. It is very powerful and quite a few games are able to run on OS X, too.
I'm thinking of Real Myst, Tasty Static, Cave Story, SRB2 or GLTron.
Besides, Carbon-based games do usually run on both OSes..