[peter_d_sherman]

>"The PDP-11/45 on which our UNIX installation is implemented is a 16-bit word (8-bit byte) computer with 144 Kbytes of core memory;

UNIX occupies 42K bytes."

Compare that to Ubuntu's requirements in 2020:

https://help.ubuntu.com/community/Installation/SystemRequire...

>"Ubuntu Desktop Edition

o 2 GHz dual core processor

o 4 GB RAM (system memory)

o 25 GB of hard-drive space (or USB stick, memory card or external drive but see LiveCD for an alternative approach)

o VGA capable of 1024x768 screen resolution

o Either a CD/DVD drive or a USB port for the installer media

o Internet access is helpful"

[musicale]

Linux distributions might be a lot smaller if a) the kernel only included drivers for a single hardware platform, single file system, text terminals, and no network devices or protocols, b) /usr/lib only included libc, and c) everything was still 32-bit.

There are certainly examples of very compact Unix-like OSes that nonetheless offer memory protection, paging/virtual memory, preemptive multitasking, and a system call interface.

[msla]

> Linux distributions might be a lot smaller if a) the kernel only included drivers for a single hardware platform, single file system, text terminals, and no network devices or protocols, b) /usr/lib only included libc, and c) everything was still 32-bit.

As for that last: The PDP-11 was a 16-bit architecture, which got somewhat interesting to work with when software began to grow functionality beyond what would comfortably fit in that address space. The 32-bit PDP-11 was going to be called the Virtual Address Extension, or the VAX; instead, the VAX was turned into a machine rather more elaborate than a "better PDP-11".

[taneliv]

Perhaps something like this is closer in functionality:

"Sufficient Flash to accommodate OpenWrt firmware image

* 4MB min (won't be able to install GUI (LuCI))

* 8MB better (will fit GUI and some other applications)

Sufficient RAM for stable operation

* 32MB min, 64MB better"

(Directly from https://openwrt.org/supported_devices)

Still a few magnitudes more than the PDP-11/45, though.

[zaptheimpaler]

Now try comparing the capabilities of UNIX on PDP to Ubuntu on a modern desktop as well

[pjmlp]

It hardly makes a difference, given how many seem to enjoy tailoring their octa core laptop with HiDPI screen to look like a PDP developer experience.

[tannhaeuser]

The elephant in the room is more, like, the conceptual simplicity, interface stability, and portability compared to the never-ending proliferation of Linux kludges ^H^H^H innovations turning out to bring as much problems as they're trying to solve, or more eg https://lwn.net/Articles/679786/

[mushufasa]

better comparison would be ubuntu server edition (no gui) 1 GHz CPU 512 MB RAM (system memory) 2.5 GB hard drive

[Waterluvian]

I doubt a PDP-11 will handle an AMD graphics card upgrade then.

[pjmlp]

It hardly makes a difference to running CLI with screen, bash and vim.

[spongeb00b]

The real overhead now is in interfacing: your CLI screen still needs to output (probably) VGA graphics, you'll need USB host support, wired and wireless networking, more sophisticated file systems...

[pjmlp]

From my point of view that is still kind of catching up with big iron UNIX and mainframes, revienting many of their ideas that were already a thing in the late 90's.

For example, my first experience with containers was with HP-UX Vault, likewise for most fancy filesystems that GNU/Linux might be getting.