from Hacker News

Modern Baby: A pioneering computer from Manchester

by klelatti on 3/11/25, 6:37 AM with 11 comments

  • by nonrandomstring on 3/11/25, 1:37 PM

    I totally love this early principle [0] for RAM by literally writing in electrons on a 2D surface and then reading them back using the electron gun.

    [0] https://en.wikipedia.org/wiki/Williams_tube

  • by rlpb on 3/11/25, 7:35 PM

    > Was the modified ENIAC less of a computer than the Manchester Baby because its program was in ROM and could not be changed by the computer?

    To me, the most remarkable property of a computer is that data and code are interchangeable. This makes it possible for the same computer to run different programs, run programs that transform programs, and so forth. It's the same fundamental concept that today means that one can "download" an app and then run it.

    (See also: Lisp, which is equally remarkable in the software space for the same reason)

    > Look at it this way: many modern microprocessors, especially small ones for embedded control, have their programs in ROM. If they are modern-style computers, then so was the modified ENIAC.

    What makes them modern-style computers, though, is that they are capable of having their firmware flashed - or at least the development versions can do this while their software is engineered. If the final product only runs a ROM, it has lost the essence of a general purpose computer, which is the fundamental and very remarkable invention that is what we actually celebrate.

  • by apignotti on 3/11/25, 6:31 PM

    You can play with an online simulator of this machine here: https://davidsharp.com/baby/online/index.html

    The simulator is originally written in Java, and the browser version is powered by CheerpJ, a WebAssembly-based JVM (https://cheerpj.com/)

  • by ooFieTh6 on 3/12/25, 4:16 PM

    I had to work on writing a simulator in Java for the SSEM/Manchester Baby as part of my University studies back in the 2000s, it was a fun task, nice to read more about it.

  • by stevefolta on 3/11/25, 8:17 PM

    > In the ENIAC the form of the [sic] that [program] storage (decimal) was quite different to that of the data that ENIAC operated on (binary).

    Huh? ENIAC was a decimal machine all the way through.