Since I mentioned the project here, I'll follow up on it here.
Using 128MB SIMMs on NetBSD with a stock ROM, stock everything centris 650:
Using tmpfs:
That's 400MB of tmpfs (RAMdisk in MacOS terms. 
), and a total of 456MB physical RAM being used. It's not 520MB because I couldn't touch the first 2 banks (interleaving means if it touches one, it touches both) of RAM SIMMs since the kernel and supporting data exceeds the soldered 8MB of physical RAM.
But hey. That's a respectable amount of RAM for these systems.
Using 128MB SIMMs on NetBSD with a stock ROM, stock everything centris 650:
Using tmpfs:
Code:
c650# df -hl
Filesystem Size Used Avail %Cap Mounted on
/dev/sd0a 3.7G 749M 2.8G 20% /
kernfs 1.0K 1.0K 0B 100% /kern
ptyfs 1.0K 1.0K 0B 100% /dev/pts
procfs 4.0K 4.0K 0B 100% /proc
tmpfs 1.3G 400M 936M 29% /mnt
Code:
load averages: 0.28, 0.96, 0.96; up 0+00:25:12 01:17:12
19 processes: 18 sleeping, 1 on CPU
CPU states: 0.7% user, 0.0% nice, 1.0% system, 0.0% interrupt, 98.3% idle
Memory: 419M Act, 4608K Exec, 7252K File, 12M Free
Swap: 922M Total, 922M FreeBut hey. That's a respectable amount of RAM for these systems.