What the KIM-1 really needs is bubble memory | Hacker News Reader

What the KIM-1 really needs is bubble memory

oldvcr.blogspot.com

My only complaint is that the connector used is not a DB-15 connector at all. It is a DA-15, because it has 15 pins in two rows on 1/10-inch centers in a "subminiature" D shell, or "D-sub".

Other sizes included "DC" with room for 37 pins, "DE" with room for 9, or for 15 crammed closer as for PC video, and DD with room for 3 rows with 50 pins (17, 16, 17).

The DE shell is of course what everybody post-PC insists on also calling "DB", as in "DB-9".

The name "subminiature" distinguishes them from "miniature", and not, which as might be imagined were bigger and even bigger yet.

https://en.m.wikipedia.org/wiki/D-subminiature

I'll correct, but compliments are also appreciated. ;)

I did geek out. I recall trying a moon-landing program running on a KIM-1, for which I guess the trick was to turn on thrust at the last possible second, to be discovered I guess by binary search.

I never knew KIM-1 ROM knew how to talk serial. Or maybe at the time I had no TTY, so ignored it. Now it makes the KIM-1 seem more interesting.

Another, more recent abandoned serial memory tech was MRAM, ironically not RAM, which was built into a million Motorola cell phones no longer in use. Or maybe I am mixing it up with something else. What ever happened to spintronics, anyway? Might it still have a future?

Do you mean the Butterfield Lunar Lander? That's a classic too. But yes, the built-in serial support is really nice.

I'd forgotten about spintronics logic!

Working with a retro computer is a good exercise for everyone to do at least once in their life. One of the things which gets lost when your working in the cloud is an understanding of the underlying architecture, and how things work at the lowest level.

It's also useful to manually do some of those steps we take for granted on modern systems. In this case it was file allocation, but there are many others which are equally illustrative.

Plus, the feeling of control and complete understanding is really addictive after awhile. 8-)

Having used retro computers since before they were retro, unless you enjoy the retro vibe you can get much the same benefits - and more useful skills for future life - by just using a microcontroller such as ESP32.

Back when retro computers were the modern hotness, it would have been astonishing that you could buy a computer with a display for ten bucks or so (https://www.amazon.com/LILYGO-T-Display-Arduino-Development-...).

Aw. My KIM-1 still works.

Which revision? I'd like to do the 4K upgrade since the decoding is already on the board, though I also have an AIM-65 configured that way and making everything fit in 1K is a fun problem to figure out.

I’ll have to check.

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