Well I became a big BeOS fan a few days ago trying it out, but unfortunately it was discontinued 
But there is Haiku, so I’d like to try that, but first, I’d like to know if these PCs are support:
*PC 1 (don’t want to run it on this PC at the time, but I’d like to know anyways)
- 3.0 Ghz dual-core Pentium D
- 1 GB of RAM
- SiS Mirage 3 integrated graphics (Monitor is 1680x1050 (but run Xubuntu at 1600x1200), 24-bit colour LCD)
- 160 GB HD
*PC 2 (the one likely to get a Haiku treatment)
- 2.4 single-core Celeron
- 256 MB of RAM
- Integrated Intel GFX (Monitor is 1280x720, 32-bit colour LCD)
- 75 GB HD
*PC 3 (already running BeOS, but…)
- 500 Mhz Pentium 3
- 64 MB of RAM
- ATI Rage Pro (Monitor is 800x600 (but run BeOS at 640x480), 16-bit colour CRT with a 60Hz refresh rate)
- 8 GB HD
Will these PCs run Haiku correctly?
the first two PC should be fine to run Haiku, but the third one seems to not have enough memory(RAM), and the screen (800*600) will be quite uncomfortable (the processor is not very powerful but it doesn’t matter).
what are the chipsets, network adapters and sound cards ?
PC 1&2 = yes
PC 3 = no*
*Increase RAM to at least 96MB to install & run from CD. Or install hard drive into other computer with more RAM, install Haiku onto drive, enable virtual memory and reinstall drive into PC3.
Can’t say for sound or network. Network is very well supported in Haiku and Sound is too with OSS.
Haiku requirements:
i586 (Pentium) or better
1 GB hard drive (AHCI/Legacy SATA or regular PATA)
128 MB RAM (without swap file to install & run LiveCD)
Any VESA 2.0 graphics card (will use VESA or native graphics driver)
Sound & network may or may not work depending on your hardware.
People have run Haiku with Intel Core i5/i7 and AMD Phenoms.
I already run BeOS on PC 3 and have no interest ont running Haiku on PC 1, my main problem is PC 2.
The PC was made in 2004 and Linux already has drivers for this PC’s networking and sound… (I do know this won’t change Haiku’s support, but it’s a benchmark…)
This also puts PC 4 outta the question. (FYI, it has a 233 Mhz processor and 28 MB of RAM. Won’t go anywhere at all)
if you do, ls /dev/audio, in terminal and have nothing in there (no driver listed), then you can install opensound driver which may give you audio. You should use installoptionalpackage from terminal to download & install but without working network driver I give direct link to actual file:
http://haiku-files.org/files/optional-packages/opensound-4.2-r1a2-x86-gcc2-2010-05-01.zip
opensound supports many sound cards and you should use it if no other Haiku audio driver loaded for you.
Give listdev info for audio & network cards & I can look them up in less than 6 minutes total to see what support there is for them.