Automatic Computing Engine - Revision history

Jnc: /* Further reading */ link AHC

2024-12-06T01:22:29Z

‎Further reading: link AHC

Jnc: /* Further reading */ +From ACE to the G-15

2024-03-25T01:53:20Z

‎Further reading: +From ACE to the G-15

Jnc: /* External links */ +The other Turing machine

2024-03-17T17:29:18Z

‎External links: +The other Turing machine

Jnc: /* External links */ +high resolution image

2024-03-17T16:48:08Z

‎External links: +high resolution image

Jnc: Note separate multiplier and divider hardware units

2024-03-17T16:35:33Z

Note separate multiplier and divider hardware units

Jnc: Minor tweaks

2024-03-17T16:14:30Z

Minor tweaks

Jnc: The name was a conscious tribute to the Analytical Engine

2024-03-17T01:30:24Z

The name was a conscious tribute to the Analytical Engine

Jnc: A good start - documentation on it is very hard to find, now

2024-03-16T16:13:32Z

A good start - documentation on it is very hard to find, now

New page

The '''Automatic Computing Engine''' (usually given as the acronym, '''ACE''') was a very early [[computer]] (the first one designed in the UK), designed by [[Alan Turing]], personally. Its [[main memory]] was mercury [[delay line]]s, and the whole [[architecture]] of the machine was adapted to their characteristics, to a degree which today is hard to imagine without seeing the details (for instance, in the use of using [[optimum coding]], to give a simple example). For its day, as a result, it was thus a very fast machine indeed, although difficult to program.

Turing did the design in late 1945, after he moved to the National Physical Laboratory - perhaps inspired by news of [[John von Neumann]]'s ''First Draft of a Report on the EDVAC''. He produced a lengthy detailed design document, ''Proposal for Development in the Mathematics Division of an Automatic Computing Engine (ACE)'', which came out in March, 1946; the NPL approved his proposal, but moved very slowly on doing anything. Turing, apparently unhappy at the delays in building it, eventually moved to Manchester University.

The NPL then produced a scaled-down prototype, the [[Pilot ACE]], starting in early 1949, and initially operational by May, 1950; it was both successful, and much copied. After a considerable delay, they then moved on to produce the full-scale ACE, starting in 1953; it was initially operational in 1958. Already obsolescent, but still quite powerful (oh, had it only been built when he first proposed it!), it soldiered on, and was shut down in February, 1967.

==Technical details==

In addition to 24 long delay lines, each of which had a capacity of 32 48-bit [[word]]s, it also had 5 4-word lines (the reduced size gave lower [[access time]]s), 4 2-word lines, and 7 1-word lines; the shorter ones had the role of [[register]]s in most computers. The time required for one word (the whole machine was [[serial]]) was termed a 'minor cycle'; a complete cycle of a long line was a 'major cycle'.

The ACE's [[instruction]]s were also 48 bits. They contained 10 fields:

{| class="wikitable"
! Field !! Width !! Description
|-
| Wait || 5 || Minor cycle in which to start instruction
|-
| Source A || 6
|-
| Source B || 6
|-
| Function || 6 || 8 groups of 8
|-
| Destination || 6
|-
| Stop || 1 || Actuated by console key
|-
| Next || 5 || Next instruction line
|-
| J || 6 || Counting area
|-
| Time || 5 || Next instruction minor cycle
|-
| Characteristic || 2 || Number of minor cycles for this instruction
|}

One bit was unused. Apparently, for sources in long lines, the minor cycle used was that selected by the 'Wait' field. Instructions contained no less than ''4'' [[address]]es; two sources, a destination, and the address of the next instruction. (The ACE had no [[Program Counter]].) Many of the destinations had side-effects.

When eventually built, the ACE was given 4 [[drum]]s (each holding 256 [[track]]s of 32 words - the same size as the large delay lines), and 6 [[magnetic tape drive]]s. [[Input/output]] used [[punched card]]s and [[paper tape]].

{{semi-stub}}

==Further reading==

* Alan Turing, B. E. Carpenter (editor), R. W. Doran (editor), ''A. M. Turing's ACE report of 1946 and other papers'', MIT Press/Tomash, Cambridge/Los Angeles, 1986
* ''ACE Programming Manual'', 1960 (not online, or re-printed, alas)
* David M. Yates, ''Turing's Legacy: A History of Computing at the National Physical Laboratory 1945-1995'', Science Museum, London, 1997 - the ACE is covered in Section 3.2
* B. Jack Copeland (editor), [https://dokumen.tips/documents/alan-turings-automatic-computing-engine.html ''Alan Turing's Automatic Computing Engine: The Master Codebreaker's Struggle to Build the Modern Computer''], Oxford University, Oxford, 2005 - essays from a number of people on various aspects of the Pilot ACE and ACE

==External links==

* [http://cs.furman.edu/~tallen/csc475/materials/Turing_Report_on_ACE.pdf Proposal for Development in the Mathematics Division of an Automatic Computing Engine] - scan of Turing's original proposal
* [https://www.alanturing.net/turing_archive/archive/index/aceindex.html Turing's Automatic Computing Engine] - NPL internal correspondence about the ACE
* [https://cds.cern.ch/record/263304/files/p230.pdf Turing and ACE: Lessons from a 1946 Computer Design] - a later paper by Carpenter about the ACE
* [http://www.cs.man.ac.uk/CCS/res/res02.htm#f Evolution of the ACE]
* [http://www.cs.man.ac.uk/CCS/res/res02.htm#g ACE hardware]

[[Category: Early Computers]]
[[Category: Unique Computers]]

@@ Line 56: / Line 56: @@
 ** [https://www.alanturing.net/turing_archive/archive/l/l09/l09.php Some Features of the ACE Computer] - a fairly complete, detailed description, from May, 1957
 * [https://cds.cern.ch/record/263304/files/p230.pdf Turing and ACE: Lessons from a 1946 Computer Design] - a later paper by Carpenter about the ACE
 * [https://fineartamerica.com/featured/ace-computer-1958-national-physical-laboratory-c-crown-copyright.html Ace Computer, 1958] - high resolution image
 * [http://www.cs.man.ac.uk/CCS/res/res02.htm#f Evolution of the ACE]

← Older revision		Revision as of 01:30, 17 March 2024
Line 1:		Line 1:
−	The '''Automatic Computing Engine''' (usually given as the acronym, '''ACE''') was a very early [[computer]] (the first one designed in the UK), designed by [[Alan Turing]], personally. Its [[main memory]] was mercury [[delay line]]s, and the whole [[architecture]] of the machine was adapted to their characteristics, to a degree which today is hard to imagine without seeing the details (for instance, in the use of using [[optimum coding]], to give a simple example). For its day, as a result, it was thus a very fast machine indeed, although difficult to program.	+	The '''Automatic Computing Engine''' (usually given as the acronym, '''ACE'''; the name was a conscious tribute to the [[Analytical Engine]]) was a very early [[computer]] (the first one designed in the UK); it was designed by [[Alan Turing]], personally. Its [[main memory]] was mercury [[delay line]]s, and the whole [[architecture]] of the machine was adapted to their characteristics, to a degree which today is hard to imagine without seeing the details (for instance, in the use of using [[optimum coding]], to give a simple example). For its day, as a result, it was thus a very fast machine indeed, although difficult to program.

	Turing did the design in late 1945, after he moved to the National Physical Laboratory - perhaps inspired by news of [[John von Neumann]]'s ''First Draft of a Report on the EDVAC''. He produced a lengthy detailed design document, ''Proposal for Development in the Mathematics Division of an Automatic Computing Engine (ACE)'', which came out in March, 1946; the NPL approved his proposal, but moved very slowly on doing anything. Turing, apparently unhappy at the delays in building it, eventually moved to Manchester University.		Turing did the design in late 1945, after he moved to the National Physical Laboratory - perhaps inspired by news of [[John von Neumann]]'s ''First Draft of a Report on the EDVAC''. He produced a lengthy detailed design document, ''Proposal for Development in the Mathematics Division of an Automatic Computing Engine (ACE)'', which came out in March, 1946; the NPL approved his proposal, but moved very slowly on doing anything. Turing, apparently unhappy at the delays in building it, eventually moved to Manchester University.

@@ Line 49: / Line 49: @@
 * David M. Yates, ''Turing's Legacy: A History of Computing at the National Physical Laboratory 1945-1995'', Science Museum, London, 1997 - the ACE is covered in Section 3.2
 * B. Jack Copeland (editor), [https://dokumen.tips/documents/alan-turings-automatic-computing-engine.html ''Alan Turing's Automatic Computing Engine: The Master Codebreaker's Struggle to Build the Modern Computer''], Oxford University, Oxford, 2005 - essays from a number of people on various aspects of the Pilot ACE and ACE
-* Harry D. Huskey, ''From ACE to the G-15'', Annals of the History of Computing, Vol. 6, No. 4, Oct0ber, 1984, pp. 350-371
+* Harry D. Huskey, ''From ACE to the G-15'', [[Annals of the History of Computing]], Vol. 6, No. 4, October, 1984, pp. 350-371
 ==External links==

@@ Line 28: / Line 28: @@
 | Next || 5 || Next instruction line
 |-
-| J || 6 || Counting area
+| Auxiliary Timing Number (J) || 6 || Counting area
 |-
 | Time || 5 || Next instruction minor cycle
@@ Line 36: / Line 36: @@
 One bit was unused. Apparently, for sources in long lines, the minor cycle used was that selected by the 'Wait' field. Instructions contained no less than ''4'' [[address]]es; two sources, a destination, and the address of the next instruction. (The ACE had no [[Program Counter]].) Many of the destinations had side-effects.
 When eventually built, the ACE was given 4 [[drum]]s (each holding 256 [[track]]s of 32 words - the same size as the large delay lines, for ease of bringing their contents in), and 6 [[magnetic tape drive]]s. [[Input/output]] used [[punched card]]s and [[paper tape]].
@@ Line 52: / Line 54: @@
 * [http://cs.furman.edu/~tallen/csc475/materials/Turing_Report_on_ACE.pdf Proposal for Development in the Mathematics Division of an Automatic Computing Engine] - scan of Turing's original proposal
 * [https://www.alanturing.net/turing_archive/archive/index/aceindex.html Turing's Automatic Computing Engine] - NPL internal correspondence about the ACE
 * [https://cds.cern.ch/record/263304/files/p230.pdf Turing and ACE: Lessons from a 1946 Computer Design] - a later paper by Carpenter about the ACE
 * [http://www.cs.man.ac.uk/CCS/res/res02.htm#f Evolution of the ACE]

@@ Line 1: / Line 1: @@
-The '''Automatic Computing Engine''' (usually given as the acronym, '''ACE'''; the name was a conscious tribute to the [[Analytical Engine]]) was a very early [[computer]] (the first one designed in the UK); it was designed by [[Alan Turing]], personally. Its [[main memory]] was mercury [[delay line]]s, and the whole [[architecture]] of the machine was adapted to their characteristics, to a degree which today is hard to imagine without seeing the details (for instance, in the use of using [[optimum coding]], to give a simple example). For its day, as a result, it was thus a very fast machine indeed, although difficult to program.
+The '''Automatic Computing Engine''' (usually given as the acronym, '''ACE'''; the name was a conscious tribute to [[Charles Babbage|Babbage]]'s [[Analytical Engine]]) was a very early [[computer]] (the first one designed in the UK); it was designed by [[Alan Turing]], personally. Its [[main memory]] was mercury [[delay line]]s, and the whole [[architecture]] of the machine was adapted to their characteristics, to a degree which today is hard to imagine without seeing the details (for instance, in the use of using [[optimum programming]], to give a simple example). For its day, as a result, it was thus a very fast machine indeed, although difficult to program.
-Turing did the design in late 1945, after he moved to the National Physical Laboratory - perhaps inspired by news of [[John von Neumann]]'s ''First Draft of a Report on the EDVAC''. He produced a lengthy detailed design document, ''Proposal for Development in the Mathematics Division of an Automatic Computing Engine (ACE)'', which came out in March, 1946; the NPL approved his proposal, but moved very slowly on doing anything. Turing, apparently unhappy at the delays in building it, eventually moved to Manchester University.
+Turing did the design in late 1945, after he moved to the National Physical Laboratory - perhaps inspired by news of [[John von Neumann]]'s ''First Draft of a Report on the EDVAC''. He produced a lengthy detailed design document, ''Proposal for Development in the Mathematics Division of an Automatic Computing Engine (ACE)'', which came out in March, 1946; the NPL approved his proposal, but moved very slowly on doing anything. Turing, apparently unhappy at the delays in building it, left the NPL in September, 1947 for a short sabbatical at Cambridge, and then moved to Manchester University.
-The NPL then produced a scaled-down prototype, the [[Pilot ACE]], starting in early 1949, and initially operational by May, 1950; it was both successful, and much copied. After a considerable delay, they then moved on to produce the full-scale ACE, starting in 1953; it was initially operational in 1958. Already obsolescent, but still quite powerful (oh, had it only been built when he first proposed it!), it soldiered on, and was shut down in February, 1967.
+The NPL then produced a scaled-down prototype, the [[Pilot ACE]], on which construction started in early 1949, and initially operational by May, 1950; it was both successful, and much copied. After another considerable delay, they then moved on to produce the full-scale ACE, starting in 1953; it was initially operational in 1958. Already obsolescent, but still quite powerful (oh, had it only been built when he first proposed it!), it soldiered on, and was shut down in February, 1967.
 ==Technical details==
@@ Line 14: / Line 14: @@
 ! Field !! Width !! Description
 |-
-| Wait || 5 || Minor cycle in which to start instruction
+| Wait || 5 || Minor cycle in which to start instruction execution
 |-
-| Source A || 6
+| Source A || 6 || Line holding source [[operand]] A
 |-
-| Source B || 6
+| Source B || 6 || Line holding source operand B
 |-
 | Function || 6 || 8 groups of 8
 |-
-| Destination || 6
+| Destination || 6 || Line where result is to be stored
 |-
 | Stop || 1 || Actuated by console key
@@ Line 37: / Line 37: @@
 One bit was unused. Apparently, for sources in long lines, the minor cycle used was that selected by the 'Wait' field. Instructions contained no less than ''4'' [[address]]es; two sources, a destination, and the address of the next instruction. (The ACE had no [[Program Counter]].) Many of the destinations had side-effects.
-When eventually built, the ACE was given 4 [[drum]]s (each holding 256 [[track]]s of 32 words - the same size as the large delay lines), and 6 [[magnetic tape drive]]s. [[Input/output]] used [[punched card]]s and [[paper tape]].
+When eventually built, the ACE was given 4 [[drum]]s (each holding 256 [[track]]s of 32 words - the same size as the large delay lines, for ease of bringing their contents in), and 6 [[magnetic tape drive]]s. [[Input/output]] used [[punched card]]s and [[paper tape]].
 {{semi-stub}}