Playing Games on a 60s Computer [video] (opens in new tab)

This is the computing I fell in love with back in the 80s/90s, when I could realistically understand most, if not all about a given computer (that applies mostly to 80s computers).

Nothing wrong with the stuff we do today, but I think some of the "magic" of fully mastering a computer and seeing all those raw commands executing at lightning speed (relatively speaking!) was lost.

Sends me back to programing a PDP-11/40 around 1972. Managed to get a lunar lander program to work, although the console was a teletype (not a cool video screen)

You can get an 8-bit MCU if you want to explore that aspect. Modern embedded programming is often on a similar low level, and even on 32-bit MCUs you’re still poking registers and directly accessing memory with no protection. You want to display something on a screen, you can just get yourself a TFT display, write the driver yourself and send a good old fashioned byte array via SPI or parallel. Meanwhile just sending pixels to the screen on a modern PC is not at all straightforward, unless you use a library abstracting everything from you.

I had the experience you describe playing around with a z80 and asm.

You can freeze the CPU with one pin, single step the whole CPU, etc.

Or things like swapping memory banks, doing something, then swapping it back and returning to the original codepath.

It's neat that it all fits in your head. You can, for any slice in time, walk through all the pin states, registers, memory locations, etc...and fully understand why they are all in the state they are.

Agreed. As much as we talk about how programming is manipulation of ideas...at the end of the day it is a very physical process too. You are manipulating actual physical things in this world. This is a fascinating concept to think about. Programming is physics.

https://news.ycombinator.com/item?id=20264848 stage0 is a bootstrapping project aimed to make the link from machine code to high level languages more understandable.

What is neat about these demonstrations is how it illustrates that a computer is just a bunch of switches. Computers got better because they were able to jam more switches into a smaller area.

You can use Forth and switch between low and high level on demand. CollapseOS is being rewritten in Forth.

These early mini computers were cost optimised.

Their earlier mainframe cousins often had features to easy "Initial Program Loading". The IBM 1401 had a load button that was hardwired to read a single punchcard (80 6bit words) into memory locations 001 to 080 and jump to it. The CDC6000 had a panel with 144 toggle switches, acting essentially as a 144 bit bootrom. (12, 12bit words) These were expensive mainframe computers, so they could usually afford some budget towards IPL functionality.

But I guess even these cheaper minicomputers were expected to stay on long enough that there was little point spending money on IPL functionality to make cold booting easier.

I also wondered this, what did the pipeline company do if/when there was a loss of power?

It's a balance between compactness and ease of converting to binary. The switches on the front panel are in binary. It's a lot easier to convert octal to binary than hexadecimal. For example:

    0o13 -> 0b1_011

versus

    0xB -> 0b1011

Octal arithmetic is pretty easy as compared to hex and some instruction sets have 3 or six bit opcodes and/operands. So confusing or no it's pretty much for the convenience of the programmer or operator.

Point him at the Twine community :) Though be careful, some of them are uhhhh "for mature audiences."

http://twinery.org/