As a software professional, I appreciate elegant design.
I was fortunate to be exposed to Unix® and other POSIX operating systems
early.
I took to heart the philosophy of: Do one thing, do it well and work
together with other such tools using the universal interface of text
streams.
Many Unix programs perform quite trivial things on their own but
combined, become powerful, general-purpose tools.
Eventually I started collecting Unix computers.
Some I repurposed from our deprecated home computers.
I bought some from the local Goodwill.
A few of the oddballs I purchased on eBay or local auctions.
A couple were donated by acquaintances in the local Linux user group.
Most I rescued from the dumpster at companies where I worked.
Many originally ran their own commercial form of Unix.
Some ran simple home computer OSs, but thanks to the proliferation
of GNU and Open Source Software in the '90s, Linux and
OpenBSD/NetBSD/FreeBSD were ported to those architectures.
Part of the hobby was getting them running again, increasing resources
(hard disk space, RAM and peripherals), adding them to my growing
network and, often, installing Linux or BSD on them in order to take
advantage of newer features and simpler software porting.
Unfortunately I never acquired any of the early DEC PDP or VAX
minicomputers, Hewlett Packard HPPAs, IBM RT or RS/6000 PowerPCs,
Silicon Graphics (SGI) workstations, an Atari ST or Amiga PC.
Many of these exhibits have decayed.
Others I simply ran out of interest and somewhere to keep them all.
As such, some have been donated or recycled.
Some remain — only the most interesting like the Motorola branded
machines, the NeXT slabs, an A/UX machine and some of the old Apples we
personally used as Mac OS desktops before they were replaced by faster
Macs.
This is a Unix museum, after all — obviously it runs a Unix-like operating
system.
One can infer that all exhibits must also be running.
Unfortunately time has caused much attrition.
I've been able to replace many parts such as RAM, disk drives, power supplies,
some I/O cards, etc. but I've lost machines to critical chips or boards going
bad.
In particular, several '80s and '90s era minicomputers and workstations
stored their boot firmware on various models of STMicro MK48T
NVRAM/timekeeping chips.
These consist of a small realtime clock micro, a SRAM and a battery.
As one might guess, eventually the battery is going to reach its
practical limit of charge/discharge cycles and make the chip a
volatile RAM.
The effect was exacerbated when I didn't power the machines frequently
enough to keep the NVRAM battery charged.
Some have been recoverable, but the necessary firmware gets more
difficult to find as time and rarity take their toll.
2. Not Intel
Ever since the emergence of the various BSD on Intel and Linux, Unix on
x86 has been easy.
And commonplace.
Boring.
Even so, I do kinda wish I had kept my AMD 8088 PC clone running Minix.
It was the first Unix I owned and it provided many great learning
experiences.
3. TCP/IP Networking
As a practical matter, I wanted to get to my Unix computers over the
network.
I installed a SSH server on all of them.
All but one had serial consoles but only a few had video, keyboard and
sometimes mouse interfaces.
So SSH was a satisfyingly practical way to go.
With Ethernet, why would I ever need more than one computer with a video
screen?
Oh yeah…
A fourth practical rule was that it was reasonably feasible to
run in my house.
This effectively meant 110VAC power, smaller than a full rack, weight
less than 100 lbs., etc.
This, unfortunately, excluded a lot of the more interesting, historical
Unix platforms.
And I needed to get exhibits cheap wholesale, at auction or rescued from
depreciation, decommission and destruction (which were the best finds).