This Ferranti Mark I computer is notable because, despite being one of the earliest electronic computers, its instruction set included 4 instructions that are now included in most modern ISAs, but which have been missing for many decades from the instruction sets of most later computers, with the exception of the supercomputers made by CDC and Cray.

Those 4 instructions, with their mnemonics in the Intel/AMD x86 CPUs are:

LZCNT (leading zero bits count), which was named "The position of the most significant digit" in this manual.

POPCNT (population count), which was named "Sideways adder" in Mark I (it is listed in a table at the end of this manual).

RDRAND (read random number), which was named "The random numbers generator" in this manual.

RDTSC (read time stamp counter), "The clock" in this manual.

It is said that some or even all of these less usual instructions had been suggested by Alan Turing himself to the designers of Ferranti Mark I.

Another notable instruction of Ferranti Mark I was used to produce an audible beep, like the internal loudspeaker of the older IBM PC compatibles, "The hooter" in this manual.

It looks like this is part of the Knuth Digital Archive Project: https://archive.computerhistory.org/resources/text/Knuth_Don.... There's some fascinating stuff in there, like this "What a Programmer Does" (https://archive.computerhistory.org/resources/text/Knuth_Don...).

A little bit easier on the eyes: https://rauterberg.employee.id.tue.nl/lecturenotes/DDM110%20...

This is dated 1950, when the Manchester "Baby" was working, but the Mark I wasn't working yet. This was five years after Von Neumann's original draft of the EDVAC design. The EDVAC itself was delivered in 1949. Actual EDVAC report [2] (reset in Tex for readability) [3].

The EDVAC report is something everyone in computer science should read, if they haven't already.

The big problem in the early days was memory. Early memory systems were not only small, but were usually delay lines, where you have to wait for the slot you want to come around, like a disk. Not random access. Both the EDVAC and the MARK I had some true CRT-type random access memory, but not much of it. The Mark I had an index register, which was missing from the EDVAC. That was the last essential piece of CPU architecture needed to make programming reasonably sane. Otherwise you had to store into your program code to index.

[1] https://en.wikipedia.org/wiki/First_Draft_of_a_Report_on_the...

[2] https://archive.org/details/firstdraftofrepo00vonn

[3] https://archive.org/details/vnedvac

"It is not difficult to see that information expressed with one set of symbols can be translated into information expressed with another sot by some suitable conventions, e.g. to convert sequences of decimal digits into sequences of O's and 1's we could replace 0 by 0000, 1 by 1000, 2 by 0100, 3 by 1100, 4 by 0010, 5 by 1010, 6 by 0110, 7 by 1110, 8 by 0001, and 9 by 1001."

I've never seen someone use this form of binary notation(little-endian?) when writing binary numbers.

Edit: I suppose he's writing the numbers in the order they'd be input into the machine.

My how things have changed.... he says "Desk Machine"... and of course I think Keyboard, Computer, Monitor, Mouse.. ;-) Instead of one of the Friden Calculators.

Like this one, seen in a storage rack somewhere deep inside a TARDIS.

https://en.wikipedia.org/wiki/Friden,_Inc.#/media/File:Fride...

Boy I love this. Both for the pleasure of reading what Turing thought his ‘experienced’ operators needed to know, and also for the glimpse back at all the engineering, physical constraints, and solutions pulled together. Within a few pages we’re talking about where on a physical circle “tubes” physical bits reside, just, you know, as a starting intro. Really amazing.

It’s interesting to see how he had to write math in this paper. Instead of being able to type it, he had to leave spaces and fill it with his own handwriting. Maybe LaTeX isn’t so bad after all.

Am I tripping or is the linked manual for the Mark II, not the Mark I?

That was interesting. I just casually clicked on the link and before I knew it I had read 20 pages.

still better than brainfuck