A Turing machine

[ChrisGreaves]

http://aturingmachine.com/index.php

[HansV]

I remember reading about Turing machines when I was a student.

There is something a bit perverse about using advanced technology including a microprocessor and LEDs to "create" a Turing machine, but of course it makes it possible to demonstrate much more of its capabilities than the extremely limited examples we could work out as students, with strips of paper, a pencil and an eraser.

[ChrisGreaves]

There is something a bit perverse ...

Nice one Hans!
I developed a single-instruction computer on the Uni W.A. CYBER-72 many years ago. It was a thrill to bring the Cyber to its knees.

[John Gray]

I developed a single-instruction computer on the Uni W.A. CYBER-72 many years ago. It was a thrill to bring the Cyber to its knees.

This single instruction was either STOP or B * (i.e. branch to the current instruction...)?

[ChrisGreaves]

This single instruction was either STOP or B * (i.e. branch to the current instruction...)?

Nice try, but no.
"Subtract And Store".
The program instruction cycle (crudely put) is:-

Code: Select all

Next:
       AC <-  (AC) - (Mem)
       Mem <- (AC)
       -> Next

I have some notes on it somewhere and will edit this post if/when I find them in the next hour or so.
(later)
Try this SUBS
I have some (Poole & Waite) STAGE2 macros for a talk I gave on the SUBS machine at a local NaSPA meeting 4 years ago.

[StuartR]

http://aturingmachine.com/index.php

What a delightful project, I really enjoyed reading that site.