Kernel.org: 5.2.9
sid (unstable): 5.2.7-1
buster (testing): 4.19.37-5+deb10u2
stretch (stable): 4.9.168-1+deb9u5
jessie (oldstable): 3.16.72-1

Debian GNU/Linux device driver check & report

DELL: Optiplex Gx1 500L

PCI IDWorks?VendorDeviceDriverKernel
80867190YesIntel Corporation440BX/ZX/DX - 82443BX/ZX/DX Host bridgeagpgart
80867191YesIntel Corporation440BX/ZX/DX - 82443BX/ZX/DX AGP bridgeagpgart
80867110YesIntel Corporation82371AB/EB/MB PIIX4 ISAignore
80867111YesIntel Corporation82371AB/EB/MB PIIX4 IDEata_piixv2.6.25-
80867112YesIntel Corporation82371AB/EB/MB PIIX4 USBusb-uhci,uhci-hcd
80867113YesIntel Corporation82371AB/EB/MB PIIX4 ACPIi2c-piix4v2.6.25-
10024742YesATI Technologies Inc3D Rage Pro AGP 1X/2Xatyfbv2.6.27-

I appended "pnpbios=off" boot-option at my lilo.conf, to make sound works with 2.6.8 kernel (snd-cs4236 alsa module), since, sometimes, the card was not recognized at boot time and  modprobe freezed if I tryed it.
You can make your custom kernel and compile rtc module which is not marked at debian's .config, and it is used by mplayer.
I don't know anything about the original ethernet card (or hard drive), since this computer came to me without it. Anything else I think it works without any problem.