| Re: Where do byte orders come from [message #396913 is a reply to message #396907] |
Wed, 22 July 2020 14:50   |
|
|
Originally posted by: Gareth Evans
On 22/07/2020 17:45, Quadibloc wrote:
> On Wednesday, July 22, 2020 at 4:05:25 AM UTC-6, Gareth Evans wrote:
>> On 22/07/2020 01:51, Alan Bowler wrote:
>>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>>
>>>> Didn’t the original -11s have to have the bootstrap toggled in from the
>>>> console?
>>>
>>> Yes. Did that a few times.
>>>
>>
>> Altogther now, off the top of my head, from 46 years ago ...
>>
>> 16701
>> 26
>> 12702
>> 352
>>
>> ... but I forget the rest!
>
> I was able to Google a page which preserves it:
>
> http://gunkies.org/wiki/PDP-11_Bootstrap_Loader
>
> Set the address to 7744.
>
> Then put the loader in:
>
> 7744 016701
> 7746 000026
> 7750 012702
> 7752 000352
> 7754 005211
> 7756 105711
> 7760 100376
> 7762 116162
> 7764 000002
> 7766 007400
> 7770 005267
> 7772 177756
> 7774 000765
>
> and then the next word needs to contain the address of the boot device, which
> may vary between systems.
Yes, thanks, and that triggers my memory of being able to read
the machine code in its neat orthogonal octal!
|
|
|
|
| Re: Where do byte orders come from [message #396921 is a reply to message #396899] |
Wed, 22 July 2020 20:39 |
Robin Vowels
Messages: 426
Registered: July 2012
Karma: 0
|
Senior Member |
|
|
On Wednesday, July 22, 2020 at 8:05:25 PM UTC+10, Gareth Evans wrote:
> On 22/07/2020 01:51, Alan Bowler wrote:
>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>
>>> Didn’t the original -11s have to have the bootstrap toggled in from the
>>> console?
>>
>> Yes. Did that a few times.
>>
>
> Altogther now, off the top of my head, from 46 years ago ...
>
> 16701
> 26
> 12702
> 352
>
> ... but I forget the rest!
ACE and DEUCE had a far better and well-designed system.
No loader was required to be in the machine.
All programs were self-loading.
Three punch cards contained 32 words to be loaded into a delay line.
The initial 4 rows of the first card contained 3 or 4 instructions
to read in the remaining 32 rows of the cards and to store them
directly in the high speed store.
|
|
|
|
| Re: Where do byte orders come from [message #396922 is a reply to message #396907] |
Wed, 22 July 2020 20:43 |
|
|
Originally posted by: Bob Eager
On Wed, 22 Jul 2020 09:45:52 -0700, Quadibloc wrote:
> On Wednesday, July 22, 2020 at 4:05:25 AM UTC-6, Gareth Evans wrote:
>> On 22/07/2020 01:51, Alan Bowler wrote:
>>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>>
>>>> Didn’t the original -11s have to have the bootstrap toggled in from
>>>> the console?
>>>
>>> Yes. Did that a few times.
>>>
>>>
>> Altogther now, off the top of my head, from 46 years ago ...
>>
>> 16701 26 12702 352
>>
>> ... but I forget the rest!
>
> I was able to Google a page which preserves it:
>
> http://gunkies.org/wiki/PDP-11_Bootstrap_Loader
>
> Set the address to 7744.
>
> Then put the loader in:
>
> 7744 016701 7746 000026 7750 012702 7752 000352 7754 005211 7756 105711
> 7760 100376 7762 116162 7764 000002 7766 007400 7770 005267 7772 177756
> 7774 000765
>
> and then the next word needs to contain the address of the boot device,
> which may vary between systems.
As it happens, I have that printed on the programming card right beside
me on the desk (I am doing PDP-11 stuff).
--
Using UNIX since v6 (1975)...
Use the BIG mirror service in the UK:
http://www.mirrorservice.org
|
|
|
|
| Re: Where do byte orders come from [message #396924 is a reply to message #396921] |
Wed, 22 July 2020 22:56 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
<robin.vowels@gmail.com> wrote:
> On Wednesday, July 22, 2020 at 8:05:25 PM UTC+10, Gareth Evans wrote:
>> On 22/07/2020 01:51, Alan Bowler wrote:
>>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>>
>>>> Didn’t the original -11s have to have the bootstrap toggled in from the
>>>> console?
>>>
>>> Yes. Did that a few times.
>>>
>>
>> Altogther now, off the top of my head, from 46 years ago ...
>>
>> 16701
>> 26
>> 12702
>> 352
>>
>> ... but I forget the rest!
>
> ACE and DEUCE had a far better and well-designed system.
> No loader was required to be in the machine.
> All programs were self-loading.
> Three punch cards contained 32 words to be loaded into a delay line.
> The initial 4 rows of the first card contained 3 or 4 instructions
> to read in the remaining 32 rows of the cards and to store them
> directly in the high speed store.
>
The only real machine I know that couldn’t do this was the CDC 6400. S/360
had a three-card loader that you could IPL from the card reader.
--
Pete
|
|
|
|
| Re: Where do byte orders come from [message #396930 is a reply to message #396924] |
Thu, 23 July 2020 01:58 |
Charlie Gibbs
Messages: 5313
Registered: January 2012
Karma: 0
|
Senior Member |
|
|
On 2020-07-23, Peter Flass <peter_flass@yahoo.com> wrote:
> <robin.vowels@gmail.com> wrote:
>
>> On Wednesday, July 22, 2020 at 8:05:25 PM UTC+10, Gareth Evans wrote:
>>
>>> On 22/07/2020 01:51, Alan Bowler wrote:
>>>
>>>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>>>
>>>> > Didn’t the original -11s have to have the bootstrap toggled in from the
>>>> > console?
>>>>
>>>> Yes. Did that a few times.
>>>
>>> Altogther now, off the top of my head, from 46 years ago ...
>>>
>>> 16701
>>> 26
>>> 12702
>>> 352
>>>
>>> ... but I forget the rest!
>>
>> ACE and DEUCE had a far better and well-designed system.
>> No loader was required to be in the machine.
>> All programs were self-loading.
>> Three punch cards contained 32 words to be loaded into a delay line.
>> The initial 4 rows of the first card contained 3 or 4 instructions
>> to read in the remaining 32 rows of the cards and to store them
>> directly in the high speed store.
>
> The only real machine I know that couldn’t do this was the CDC 6400. S/360
> had a three-card loader that you could IPL from the card reader.
I wrote a one-card loader for the Univac 9300 (sort of like a 360/20)
which could load up to 16 subsequent cards (1280 bytes) into contiguous
memory locations and jump to the beginning. If you couldn't do what you
wanted in 1280 bytes (e.g. my 3-card memory dump), you could always write
a loader that would bring in whatever you wanted. (Mind you, that's what
the standard cards on the front of a binary deck did...)
--
/~\ Charlie Gibbs | Microsoft is a dictatorship.
\ / <cgibbs@kltpzyxm.invalid> | Apple is a cult.
X I'm really at ac.dekanfrus | Linux is anarchy.
/ \ if you read it the right way. | Pick your poison.
|
|
|
|
| Re: Where do byte orders come from [message #396932 is a reply to message #396924] |
Thu, 23 July 2020 04:55 |
Robin Vowels
Messages: 426
Registered: July 2012
Karma: 0
|
Senior Member |
|
|
On Thursday, July 23, 2020 at 12:56:51 PM UTC+10, Peter Flass wrote:
> <r......@gmail.com> wrote:
>> On Wednesday, July 22, 2020 at 8:05:25 PM UTC+10, Gareth Evans wrote:
>>> On 22/07/2020 01:51, Alan Bowler wrote:
>>>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>>>
>>>> > Didn’t the original -11s have to have the bootstrap toggled in from the
>>>> > console?
>>>>
>>>> Yes. Did that a few times.
>>>>
>>>
>>> Altogther now, off the top of my head, from 46 years ago ...
>>>
>>> 16701
>>> 26
>>> 12702
>>> 352
>>>
>>> ... but I forget the rest!
>>
>> ACE and DEUCE had a far better and well-designed system.
>> No loader was required to be in the machine.
>> All programs were self-loading.
>> Three punch cards contained 32 words to be loaded into a delay line.
>> The initial 4 rows of the first card contained 3 or 4 instructions
>> to read in the remaining 32 rows of the cards and to store them
>> directly in the high speed store.
> The only real machine I know that couldn’t do this was the CDC 6400. S/360
> had a three-card loader that you could IPL from the card reader.
A number of the early machines had the loader in some form
of magnetic storage. I think that these computers had only
paper tape input, so the loader needed to assemble instruction
words from successive rows of paper tape.
As I said, ACE (1951) and DEUCE did not have any in-store
loader. For any program, the operator placed a deck of
program cards in the card reader and pressed a key on
the card reader, which cleared the high-speed store
and started the card reader.
The self-loading instructions on the first four rows of
a set of 3 cards were ordinary 32-bit binary-image instructions.
(as were the contents of the next 32 rows of the three cards).
|
|
|
|
| Re: Where do byte orders come from [message #396933 is a reply to message #396924] |
Thu, 23 July 2020 05:33 |
|
|
Originally posted by: Bob Eager
On Wed, 22 Jul 2020 19:56:49 -0700, Peter Flass wrote:
> <robin.vowels@gmail.com> wrote:
>> On Wednesday, July 22, 2020 at 8:05:25 PM UTC+10, Gareth Evans wrote:
>>> On 22/07/2020 01:51, Alan Bowler wrote:
>>>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>>>
>>>> > Didn’t the original -11s have to have the bootstrap toggled in from
>>>> > the console?
>>>>
>>>> Yes. Did that a few times.
>>>>
>>>>
>>> Altogther now, off the top of my head, from 46 years ago ...
>>>
>>> 16701 26 12702 352
>>>
>>> ... but I forget the rest!
>>
>> ACE and DEUCE had a far better and well-designed system.
>> No loader was required to be in the machine.
>> All programs were self-loading.
>> Three punch cards contained 32 words to be loaded into a delay line.
>> The initial 4 rows of the first card contained 3 or 4 instructions to
>> read in the remaining 32 rows of the cards and to store them directly
>> in the high speed store.
>>
>>
> The only real machine I know that couldn’t do this was the CDC 6400.
> S/360 had a three-card loader that you could IPL from the card reader.
Three cards? The Elliott 4100 series could do it on 12 rows (4 words) of
paper tape.
--
Using UNIX since v6 (1975)...
Use the BIG mirror service in the UK:
http://www.mirrorservice.org
|
|
|
|
| Re: Where do byte orders come from [message #396937 is a reply to message #396922] |
Thu, 23 July 2020 07:08 |
|
|
Originally posted by: Gareth Evans
On 23/07/2020 01:43, Bob Eager wrote:
> On Wed, 22 Jul 2020 09:45:52 -0700, Quadibloc wrote:
>
>> On Wednesday, July 22, 2020 at 4:05:25 AM UTC-6, Gareth Evans wrote:
>>> On 22/07/2020 01:51, Alan Bowler wrote:
>>>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>>>
>>>> > Didn’t the original -11s have to have the bootstrap toggled in from
>>>> > the console?
>>>>
>>>> Yes. Did that a few times.
>>>>
>>>>
>>> Altogther now, off the top of my head, from 46 years ago ...
>>>
>>> 16701 26 12702 352
>>>
>>> ... but I forget the rest!
>>
>> I was able to Google a page which preserves it:
>>
>> http://gunkies.org/wiki/PDP-11_Bootstrap_Loader
>>
>> Set the address to 7744.
>>
>> Then put the loader in:
>>
>> 7744 016701 7746 000026 7750 012702 7752 000352 7754 005211 7756 105711
>> 7760 100376 7762 116162 7764 000002 7766 007400 7770 005267 7772 177756
>> 7774 000765
>>
>> and then the next word needs to contain the address of the boot device,
>> which may vary between systems.
>
> As it happens, I have that printed on the programming card right beside
> me on the desk (I am doing PDP-11 stuff).
>
Yes; should've thought of that, as I have PDP11 programming
cards from 1971 and also a fair selection of PDP8 and PDP11
manuals from that time.
PDP11 - undergraduate internship in the summer of 1971
and then a PDP11 assembler programmer from 1972 to 1981.
PDP8 - Final year at Essex in 1972 studying Computer
and Communications Engineering as a 3rd year specialism
of Electronics, we had the PDP8 as study examples both
for hardware and software.
Also, from 1971 I've a sales glossy, "Digital Products
and Applications" which covered the whole of their then
range.
(Reminder to self; must gird the loins and actually
assemble the PiDP8 and PiDP11 kits :-) )
|
|
|
|
| Re: Where do byte orders come from [message #396941 is a reply to message #396922] |
Thu, 23 July 2020 08:09 |
|
|
Originally posted by: Andy Walker
On 23/07/2020 01:43, Bob Eager wrote:
> On Wed, 22 Jul 2020 09:45:52 -0700, Quadibloc wrote:
[...]
>> Set the address to 7744.
>> Then put the loader in:
>> 7744 016701 [...]
> As it happens, I have that printed on the programming card right beside
> me on the desk (I am doing PDP-11 stuff).
I was doing that in the '70s, and have now [of course] forgotten
all the details, but I have a vague memory that someone found a way of
shortening that by a couple of words, which makes a big difference when
you're setting switches by hand. Any takers?
Anyway, it was a great moment when the 11/05 was replaced by an
11/34, which just booted up into Unix "automatically".
The 11/05 was in a room carved out of a basement area previously
used as a "Gents". There had regularly been puddles on the floor, which
were ascribed to carelessness by the users. But when it was a computer
room, it became clear that the problem lay elsewhere. The University
wasn't disposed to do much about it -- yes, the building had been built
directly over a stream, yes, the [expensive] architect had bungled, but
what's the problem, really? "Well, there's a puddle half-way across
the floor, it's raining, the puddle is growing, and if it gets to where
the computers are, it could blow them, and cost ..." "Oh, /computers/.
Right." There was a pump installed within the hour.
--
Andy Walker,
Nottingham.
|
|
|
|
| Re: Where do byte orders come from [message #396942 is a reply to message #396924] |
Thu, 23 July 2020 08:00 |
Ahem A Rivet's Shot
Messages: 4843
Registered: January 2012
Karma: 0
|
Senior Member |
|
|
On Wed, 22 Jul 2020 19:56:49 -0700
Peter Flass <peter_flass@yahoo.com> wrote:
> S/360 had a three-card loader that you could IPL from the card reader.
The 1130 had a single card loader that IPL'd from the card reader,
attempting to copy one in an 029 was a bad idea.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:\>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
|
|
|
|
| Re: Where do byte orders come from [message #396945 is a reply to message #396941] |
Thu, 23 July 2020 09:57 |
|
|
Originally posted by: Gareth Evans
On 23/07/2020 13:09, Andy Walker wrote:
> On 23/07/2020 01:43, Bob Eager wrote:
>> On Wed, 22 Jul 2020 09:45:52 -0700, Quadibloc wrote:
> [...]
>>> Set the address to 7744.
>>> Then put the loader in:
>>> 7744 016701 [...]
>> As it happens, I have that printed on the programming card right beside
>> me on the desk (I am doing PDP-11 stuff).
>
> I was doing that in the '70s, and have now [of course] forgotten
> all the details, but I have a vague memory that someone found a way of
> shortening that by a couple of words, which makes a big difference when
> you're setting switches by hand. Any takers?
You could save the input device directly in the first instruction as ...
12701
177560
instead of picking it up from the end, but can't see how
to save another word!
|
|
|
|
| Re: Where do byte orders come from [message #396946 is a reply to message #396924] |
Thu, 23 July 2020 11:11 |
scott
Messages: 4237
Registered: February 2012
Karma: 0
|
Senior Member |
|
|
Peter Flass <peter_flass@yahoo.com> writes:
> <robin.vowels@gmail.com> wrote:
>> On Wednesday, July 22, 2020 at 8:05:25 PM UTC+10, Gareth Evans wrote:
>>> On 22/07/2020 01:51, Alan Bowler wrote:
>>>> On 2019-08-08 8:41 p.m., Peter Flass wrote:
>>>>
>>>> > Didn’t the original -11s have to have the bootstrap toggled in from the
>>>> > console?
>>>>
>>>> Yes. Did that a few times.
>>>>
>>>
>>> Altogther now, off the top of my head, from 46 years ago ...
>>>
>>> 16701
>>> 26
>>> 12702
>>> 352
>>>
>>> ... but I forget the rest!
>>
>> ACE and DEUCE had a far better and well-designed system.
>> No loader was required to be in the machine.
>> All programs were self-loading.
>> Three punch cards contained 32 words to be loaded into a delay line.
>> The initial 4 rows of the first card contained 3 or 4 instructions
>> to read in the remaining 32 rows of the cards and to store them
>> directly in the high speed store.
>>
>
> The only real machine I know that couldn’t do this was the CDC 6400. S/360
> had a three-card loader that you could IPL from the card reader.
Burroughs medium systems used a one-card loader, and the 'load' button
was hardwired to issue a read from the card reader (or strapped to read
the first sector of disk) and transfer control to the buffer after the
read completed.
|
|
|
|
|
|
| Re: Where do byte orders come from [message #396962 is a reply to message #396949] |
Thu, 23 July 2020 19:45 |
Alfred Falk
Messages: 195
Registered: June 2012
Karma: 0
|
Senior Member |
|
|
Joe Pfeiffer <pfeiffer@cs.nmsu.edu> wrote in
news:1btuxytchd.fsf@pfeifferfamily.net:
> I remember the Nova with floppy disk drive had a two-instruction
> loader -- first one started a DMA transfer from the disk to address 0,
> second one was a jmp to itself.
Correct. In full:
Reset
000376
Examine Sets address for subsquent deposits
0601xx NIOS xx Start IO on device xx (typically 33 or 37)
Deposit
000377 JMP 377
Deposit Next
000376
Start
(I had to look that up. Later machine with automatic load made it even
simpler:
Reset
xx device address (typically 33 or 37)
Start
|
|
|
|
| Re: Where do byte orders come from [message #396971 is a reply to message #385903] |
Fri, 24 July 2020 06:51 |
Quadibloc
Messages: 4399
Registered: June 2012
Karma: 0
|
Senior Member |
|
|
On Saturday, August 10, 2019 at 1:04:57 PM UTC-6, googlegroups jmfbahciv wrote:
> Who did the design? If it was someone who left to start up Data General,
> perhaps reading _The Soul of a Machine_ might give hints.
The guy who left to start up Data General, Edson de Castro, designed the PDP-5
architecture which was later used in the PDP-8. He left specifically because they
rejected his design for their 16-bit computer, and made the PDP-11 instead.
John Savard
|
|
|
|
| Re: Where do byte orders come from [message #396972 is a reply to message #396971] |
Fri, 24 July 2020 06:54 |
Quadibloc
Messages: 4399
Registered: June 2012
Karma: 0
|
Senior Member |
|
|
On Friday, July 24, 2020 at 4:51:27 AM UTC-6, Quadibloc wrote:
> On Saturday, August 10, 2019 at 1:04:57 PM UTC-6, googlegroups jmfbahciv wrote:
>
>> Who did the design? If it was someone who left to start up Data General,
>> perhaps reading _The Soul of a Machine_ might give hints.
>
> The guy who left to start up Data General, Edson de Castro, designed the PDP-5
> architecture which was later used in the PDP-8. He left specifically because they
> rejected his design for their 16-bit computer, and made the PDP-11 instead.
While this page doesn't explain when the decision to include little-endian was
made, it does name the originator of the design for the PDP-11: Harold
McFarland.
https://history-computer.com/ModernComputer/Electronic/PDP-1 1.html
John Savard
|
|
|
|
| Re: Where do byte orders come from [message #396973 is a reply to message #386009] |
Fri, 24 July 2020 06:57 |
Quadibloc
Messages: 4399
Registered: June 2012
Karma: 0
|
Senior Member |
|
|
On Tuesday, August 13, 2019 at 6:00:34 PM UTC-6, Quadibloc wrote:
> On Tuesday, August 13, 2019 at 3:47:31 PM UTC-6, Rich Alderson wrote:
>> Quadibloc <jsavard@ecn.ab.ca> writes:
>
>>> Edson de Castro, who designed the original Nova, and used to work at
>>> DEC... left because DEC went with the PDP-11 instead of his design. So he
>>> wasn't working on the PDP-11.
>
>> This is the mythology.
>
> Where did I say that the design of Edson de Castro that DEC didn't go with - was
> the same design as he used later for the Nova?
After all, since he worked on his original PDP-11 proposal while employed by
DEC, they could have sued him if he just used it without changes. And if the
PDP-11 was supposed to be 'better', then instead of an old-fashioned 'me-too'
design that looked like the HP 211x or the Honeywell 316/516, a new design that
he could argue was 'the best of both worlds' might be just the thing.
John Savard
|
|
|
|
| Re: Where do byte orders come from [message #396974 is a reply to message #396972] |
Fri, 24 July 2020 07:00 |
Quadibloc
Messages: 4399
Registered: June 2012
Karma: 0
|
Senior Member |
|
|
On Friday, July 24, 2020 at 4:54:17 AM UTC-6, Quadibloc wrote:
> On Friday, July 24, 2020 at 4:51:27 AM UTC-6, Quadibloc wrote:
>> On Saturday, August 10, 2019 at 1:04:57 PM UTC-6, googlegroups jmfbahciv wrote:
>>
>>> Who did the design? If it was someone who left to start up Data General,
>>> perhaps reading _The Soul of a Machine_ might give hints.
>>
>> The guy who left to start up Data General, Edson de Castro, designed the PDP-5
>> architecture which was later used in the PDP-8. He left specifically because they
>> rejected his design for their 16-bit computer, and made the PDP-11 instead.
>
> While this page doesn't explain when the decision to include little-endian was
> made, it does name the originator of the design for the PDP-11: Harold
> McFarland.
>
> https://history-computer.com/ModernComputer/Electronic/PDP-1 1.html
And this page
http://hampage.hu/pdp-11/birth.html
has some more information.
John Savard
|
|
|
|
| Re: Data General, was Where do byte orders come from [message #396979 is a reply to message #396973] |
Fri, 24 July 2020 11:47 |
John Levine
Messages: 1405
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
>>>> Edson de Castro, who designed the original Nova, and used to work at
>>>> DEC... left because DEC went with the PDP-11 instead of his design. So he
>>>> wasn't working on the PDP-11.
>>
>>> This is the mythology.
>>
>> Where did I say that the design of Edson de Castro that DEC didn't go with - was
>> the same design as he used later for the Nova?
>
> After all, since he worked on his original PDP-11 proposal while employed by
> DEC, they could have sued him if he just used it without changes. And if the
> PDP-11 was supposed to be 'better', then instead of an old-fashioned 'me-too'
> design that looked like the HP 211x or the Honeywell 316/516, a new design that
> he could argue was 'the best of both worlds' might be just the thing.
The Nova was a very good design for the time. It was straightforward
to program and more importantly, straightforward to manufacture. I
gather it was similar to the rejected PDP-X but not identical, which
isn't surprising since its designers had more time to reconsider and
refine the design.
--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly
|
|
|
|
|
|
| Re: Where do byte orders come from [message #396981 is a reply to message #396980] |
Fri, 24 July 2020 12:23 |
Quadibloc
Messages: 4399
Registered: June 2012
Karma: 0
|
Senior Member |
|
|
On Friday, July 24, 2020 at 9:54:58 AM UTC-6, John Levine wrote:
> In article <0972e4a9-2307-449f-8d23-9ff404af98b3o@googlegroups.com>,
> Quadibloc <jsavard@ecn.ab.ca> wrote:
>> While this page doesn't explain when the decision to include little-endian was
>> made, it does name the originator of the design for the PDP-11: Harold
>> McFarland.
>>
>> https://history-computer.com/ModernComputer/Electronic/PDP-1 1.html
>
> I have been trying for many years to find out why DEC used a
> little-endian byte order in the PDP-11 rather than the big-endian that
> all then-existing byte addressable machine used.
> So far nobody has 'fessed up, although lots of people have sent along
> uninformed speculation. I know lots of reasons that DEC might have
> chosen little-endian, but I don't know why they actually did.
Incidentally, from some other sources, I see that MacFarland brought over the
"nucleus" of the PDP-11 design. In "What Have We Learned from the PDP-11",
Gordon Bell notes that giving it byte addressing was one of the significant ways
in which it was an improvement on previous architectures.
In the absence of a more detailed account of the development of the PDP-11, I'm
afraid that "speculation" is all we have.
John Savard
|
|
|
|
| Re: Where do byte orders come from [message #396982 is a reply to message #396980] |
Fri, 24 July 2020 12:28 |
|
|
Originally posted by: Gareth Evans
On 24/07/2020 16:54, John Levine wrote:
> In article <0972e4a9-2307-449f-8d23-9ff404af98b3o@googlegroups.com>,
> Quadibloc <jsavard@ecn.ab.ca> wrote:
>> While this page doesn't explain when the decision to include little-endian was
>> made, it does name the originator of the design for the PDP-11: Harold
>> McFarland.
>>
>> https://history-computer.com/ModernComputer/Electronic/PDP-1 1.html
>
> I have been trying for many years to find out why DEC used a
> little-endian byte order in the PDP-11 rather than the big-endian that
> all then-existing byte addressable machine used.
>
> So far nobody has 'fessed up, although lots of people have sent along
> uninformed speculation. I know lots of reasons that DEC might have
> chosen little-endian, but I don't know why they actually did.
>
>
>
But Little Endian is the obvious and logical approach,
otherwise when dealing with multi precision you have to fart
about to get to the least significant byte when presented
with the address of the variable in memory.
The only justification for Big Endian seems to come from
lazy programmers who need their hands held and nose
wiped when looking at core dumps.
HTH YMMV EOE
|
|
|
|
| Re: Where do byte orders come from [message #396984 is a reply to message #396982] |
Fri, 24 July 2020 12:56 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
Gareth Evans <headstone255@yahoo.com> wrote:
> On 24/07/2020 16:54, John Levine wrote:
>> In article <0972e4a9-2307-449f-8d23-9ff404af98b3o@googlegroups.com>,
>> Quadibloc <jsavard@ecn.ab.ca> wrote:
>>> While this page doesn't explain when the decision to include little-endian was
>>> made, it does name the originator of the design for the PDP-11: Harold
>>> McFarland.
>>>
>>> https://history-computer.com/ModernComputer/Electronic/PDP-1 1.html
>>
>> I have been trying for many years to find out why DEC used a
>> little-endian byte order in the PDP-11 rather than the big-endian that
>> all then-existing byte addressable machine used.
>>
>> So far nobody has 'fessed up, although lots of people have sent along
>> uninformed speculation. I know lots of reasons that DEC might have
>> chosen little-endian, but I don't know why they actually did.
>>
>>
>>
>
> But Little Endian is the obvious and logical approach,
> otherwise when dealing with multi precision you have to fart
> about to get to the least significant byte when presented
> with the address of the variable in memory.
>
> The only justification for Big Endian seems to come from
> lazy programmers who need their hands held and nose
> wiped when looking at core dumps.
>
No, big-endian is the logical approach for any machine bigger that an 8008,
since words are operated on, and brought into the ALU, as a unit.
Big-endian is the way people think of numbers, otherwise you’d write
amounts like 00.000,1$ for a thousand dollars.
--
Pete
|
|
|
|
| Re: Where do byte orders come from [message #396986 is a reply to message #396982] |
Fri, 24 July 2020 13:32 |
Quadibloc
Messages: 4399
Registered: June 2012
Karma: 0
|
Senior Member |
|
|
On Friday, July 24, 2020 at 10:28:13 AM UTC-6, Gareth Evans wrote:
> The only justification for Big Endian seems to come from
> lazy programmers who need their hands held and nose
> wiped when looking at core dumps.
In that case, Big-Endian does not go far enough. Clearly we also have to change
computers over from doing their arithmetic in incomprehensible binary to
calculating everything in decimal so that the contents of storage will make
sense.
We have the technology to do so now without wasting copious amounts of memory -
Chen-Ho encoding!
John Savard
|
|
|
|
| Re: Data General, was Where do byte orders come from [message #396987 is a reply to message #396979] |
Fri, 24 July 2020 13:32 |
Jon Elson
Messages: 646
Registered: April 2013
Karma: 0
|
Senior Member |
|
|
John Levine wrote:
> The Nova was a very good design for the time. It was straightforward
> to program and more importantly, straightforward to manufacture. I
> gather it was similar to the rejected PDP-X but not identical, which
> isn't surprising since its designers had more time to reconsider and
> refine the design.
>
Having programmed both the Nova and the PDP-11, the PDP-11 was light years
ahead of the Nova. The Nova was basically a PDP-8 extended to a 16 bit
word. Yes, it had 4 registers, which was a huge improvement over the PDP-8.
But, I think the Nova was an indication that DeCastro was stuck in the past,
and just wanted to make slight improvements to the PDP-8. The PDP-11 was a
bold step into a new way of thinking, a whole new concept of CPU
architecture. Hopefully I don't have to detail the differences here.
(And, my memory of the Nova has faded largely into the distant past,
I last used one 45 years ago!)
Jon
|
|
|
|
| Re: Where do byte orders come from [message #396988 is a reply to message #396984] |
Fri, 24 July 2020 14:08 |
|
|
Originally posted by: Radey Shouman
Peter Flass <peter_flass@yahoo.com> writes:
> Gareth Evans <headstone255@yahoo.com> wrote:
>> On 24/07/2020 16:54, John Levine wrote:
>>> In article <0972e4a9-2307-449f-8d23-9ff404af98b3o@googlegroups.com>,
>>> Quadibloc <jsavard@ecn.ab.ca> wrote:
>>>> While this page doesn't explain when the decision to include
>>>> little-endian was
>>>> made, it does name the originator of the design for the PDP-11: Harold
>>>> McFarland.
>>>>
>>>> https://history-computer.com/ModernComputer/Electronic/PDP-1 1.html
>>>
>>> I have been trying for many years to find out why DEC used a
>>> little-endian byte order in the PDP-11 rather than the big-endian that
>>> all then-existing byte addressable machine used.
>>>
>>> So far nobody has 'fessed up, although lots of people have sent along
>>> uninformed speculation. I know lots of reasons that DEC might have
>>> chosen little-endian, but I don't know why they actually did.
>>>
>>>
>>>
>>
>> But Little Endian is the obvious and logical approach,
>> otherwise when dealing with multi precision you have to fart
>> about to get to the least significant byte when presented
>> with the address of the variable in memory.
>>
>> The only justification for Big Endian seems to come from
>> lazy programmers who need their hands held and nose
>> wiped when looking at core dumps.
>>
>
> No, big-endian is the logical approach for any machine bigger that an 8008,
> since words are operated on, and brought into the ALU, as a unit.
> Big-endian is the way people think of numbers, otherwise you’d write
> amounts like 00.000,1$ for a thousand dollars.
When writing Arabic* that's exactly how it's done. That is, the digit
order is the same as it is in Latin script, which is opposite the letter
order for words. Although "arabic numerals" is perhaps a misattribution
it does seem that that is whence they were adopted by Europeans. It
seems they just got the endianness wrong -- to be consistent they should
have reversed the order.
Least significant digit first is also exactly how numbers are written
when they are being calculated by hand, which was the point of
zero-based notation in the first place.
* I would guess this is true of other languages using Arabic script,
like Farsi and Urdu. No idea about Hebrew.
|
|
|
|
| Re: Where do byte orders come from [message #396989 is a reply to message #396986] |
Fri, 24 July 2020 14:45 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
Quadibloc <jsavard@ecn.ab.ca> wrote:
> On Friday, July 24, 2020 at 10:28:13 AM UTC-6, Gareth Evans wrote:
>
>> The only justification for Big Endian seems to come from
>> lazy programmers who need their hands held and nose
>> wiped when looking at core dumps.
>
> In that case, Big-Endian does not go far enough. Clearly we also have to change
> computers over from doing their arithmetic in incomprehensible binary to
> calculating everything in decimal so that the contents of storage will make
> sense.
Made sense years ago. It also allows unlimited-precision arithmetic, with
no concerns about word size.
>
> We have the technology to do so now without wasting copious amounts of memory -
> Chen-Ho encoding!
>
> John Savard
>
--
Pete
|
|
|
|
| Re: Data General, was Where do byte orders come from [message #396990 is a reply to message #396987] |
Fri, 24 July 2020 14:45 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
Jon Elson <elson@pico-systems.com> wrote:
> John Levine wrote:
>
>
>> The Nova was a very good design for the time. It was straightforward
>> to program and more importantly, straightforward to manufacture. I
>> gather it was similar to the rejected PDP-X but not identical, which
>> isn't surprising since its designers had more time to reconsider and
>> refine the design.
>>
> Having programmed both the Nova and the PDP-11, the PDP-11 was light years
> ahead of the Nova. The Nova was basically a PDP-8 extended to a 16 bit
> word. Yes, it had 4 registers, which was a huge improvement over the PDP-8.
> But, I think the Nova was an indication that DeCastro was stuck in the past,
> and just wanted to make slight improvements to the PDP-8. The PDP-11 was a
> bold step into a new way of thinking, a whole new concept of CPU
> architecture. Hopefully I don't have to detail the differences here.
> (And, my memory of the Nova has faded largely into the distant past,
> I last used one 45 years ago!)
>
Reading Bell’s paper it appears that the Nova was based on the DEC “PDP-X”
design that was rejected in favor of the PDP-11.
--
Pete
|
|
|
|
| Re: Data General, was Where do byte orders come from [message #396991 is a reply to message #396987] |
Fri, 24 July 2020 15:28 |
John Levine
Messages: 1405
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
In article <Z96dnZpUvreohobCnZ2dnUU7-YvNnZ2d@giganews.com>,
Jon Elson <elson@pico-systems.com> wrote:
>> The Nova was a very good design for the time. It was straightforward
>> to program and more importantly, straightforward to manufacture. I
>> gather it was similar to the rejected PDP-X but not identical, which
>> isn't surprising since its designers had more time to reconsider and
>> refine the design.
>>
> Having programmed both the Nova and the PDP-11, the PDP-11 was light years
> ahead of the Nova. The Nova was basically a PDP-8 extended to a 16 bit
> word. Yes, it had 4 registers, which was a huge improvement over the PDP-8.
> But, I think the Nova was an indication that DeCastro was stuck in the past,
> and just wanted to make slight improvements to the PDP-8.
I agree the PDP-11 was more fun to program, but the Nova was an
excellent piece of engineering. It was two large circuit boards that
pluggeed into a simple backplane so it was cheap and easy to
manufacture. The Nova shipped in 1969 at a base price of $4K or $8K
for a usable configuration. The PDP-11/20 shipped a year later priced
at $20K, partly because it was a more complex design, but also because
it was built from many small modules that plugged into a custom wired
backplane.
Eventually the PDP-11 won as the extra complexity became cheaper to
implement, and the advantages of byte addressing became more
compelling, but DG sold a whole lot of computers, mostly through OEMs
who packaged them into something else so the end customer didn't do
the programming.
DEC's Omnibus in 1971 was a backplane for the PDP-8/E and DEC came
up with one for the PDP-11 around 1973.
--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly
|
|
|
|
| Re: Where do byte orders come from [message #396992 is a reply to message #396982] |
Fri, 24 July 2020 15:30 |
John Levine
Messages: 1405
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
In article <rff26m$d9g$1@dont-email.me>,
Gareth Evans <headstone255@yahoo.com> wrote:
>> So far nobody has 'fessed up, although lots of people have sent along
>> uninformed speculation. I know lots of reasons that DEC might have
>> chosen little-endian, but I don't know why they actually did.
> But Little Endian is the obvious and logical approach, ...
Like I said, we have plenty of uninformed speculation, but no actual
facts.
Personally, I've done more programming on little-endian machines than
big-endian but I don't feel strongly about it.
--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly
|
|
|
|
| Re: Where do byte orders come from [message #396993 is a reply to message #396989] |
Fri, 24 July 2020 15:32 |
scott
Messages: 4237
Registered: February 2012
Karma: 0
|
Senior Member |
|
|
Peter Flass <peter_flass@yahoo.com> writes:
> Quadibloc <jsavard@ecn.ab.ca> wrote:
>> On Friday, July 24, 2020 at 10:28:13 AM UTC-6, Gareth Evans wrote:
>>
>>> The only justification for Big Endian seems to come from
>>> lazy programmers who need their hands held and nose
>>> wiped when looking at core dumps.
>>
>> In that case, Big-Endian does not go far enough. Clearly we also have to change
>> computers over from doing their arithmetic in incomprehensible binary to
>> calculating everything in decimal so that the contents of storage will make
>> sense.
>
> Made sense years ago. It also allows unlimited-precision arithmetic, with
> no concerns about word size.
Well, to be fair, even a BCD machine generally has an underlying
"word" size of some form. Burroughs medium systems, while supporting
operand lengths of up to 100 digits, still fetched from memory in 10 digit
(40 bit) chunks.
Note that on those systems the most significant digit had the lowest
address, and the hardware adder started with the most significant digit
(if the field lengths of both operands were different, the shorter had
implied leading zeros). The algorithm worked form MSD to LSD so that
it could catch overflow immediately and not store a partial result on
overflow. It did this by counting leading digit-by-digit sums of
9 until overflow was detected or an single digit add summed to less
than 9 (proving the overflow of the receiving field was not possible)
before storing the result.
|
|
|
|
| Re: Where do byte orders come from [message #396996 is a reply to message #396986] |
Fri, 24 July 2020 15:54 |
Ahem A Rivet's Shot
Messages: 4843
Registered: January 2012
Karma: 0
|
Senior Member |
|
|
On Fri, 24 Jul 2020 10:32:36 -0700 (PDT)
Quadibloc <jsavard@ecn.ab.ca> wrote:
> In that case, Big-Endian does not go far enough. Clearly we also have to
> change computers over from doing their arithmetic in incomprehensible
> binary to calculating everything in decimal so that the contents of
> storage will make sense.
Careful now, you'll re-invent ENIAC soon.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:\>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
|
|
|
|
| Re: Where do byte orders come from [message #396998 is a reply to message #396980] |
Fri, 24 July 2020 16:06 |
Ahem A Rivet's Shot
Messages: 4843
Registered: January 2012
Karma: 0
|
Senior Member |
|
|
On Fri, 24 Jul 2020 15:54:57 -0000 (UTC)
John Levine <johnl@taugh.com> wrote:
> So far nobody has 'fessed up, although lots of people have sent along
> uninformed speculation. I know lots of reasons that DEC might have
> chosen little-endian, but I don't know why they actually did.
I don't know either but I'd bet it wasn't any single reason but
rather an assessment that on balance it was probably the better option.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:\>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
|
|
|
|
| Re: Where do byte orders come from [message #396999 is a reply to message #396986] |
Fri, 24 July 2020 16:40 |
Dan Espen
Messages: 3867
Registered: January 2012
Karma: 0
|
Senior Member |
|
|
Quadibloc <jsavard@ecn.ab.ca> writes:
> On Friday, July 24, 2020 at 10:28:13 AM UTC-6, Gareth Evans wrote:
>
>> The only justification for Big Endian seems to come from lazy
>> programmers who need their hands held and nose wiped when looking at
>> core dumps.
>
> In that case, Big-Endian does not go far enough. Clearly we also have
> to change computers over from doing their arithmetic in
> incomprehensible binary to calculating everything in decimal so that
> the contents of storage will make sense.
>
> We have the technology to do so now without wasting copious amounts of
> memory - Chen-Ho encoding!
Calculating everything in decimal makes a lot of sense. For business
applications the input and output must be decimal and the data has a
small amount of calculation done to it before it must be printed or
displayed.
Back in the day, I ran performance tests for decimal add vs. the CVB
and CVD instructions. The 2 conversion instructions took 10 times
longer than an add.
The S/360 does decimal arithmetic, but only after the data is packed.
That's a trade off of space for ease of use. Having started programming
on 14xx equipment, I miss the simplicity. I don't think the space
saving was a good trade-off.
The 14xx gave us numbers only limited in magnitude by storage size. The
key to that technology was an extra delimiting bit (the wordmark) in a
character. As much as I liked the word mark concept, I'm unsure that it
should have been carried forward.
I did a lot of Assembler and COBOL for business applications on S/360.
I can't think of any time it made sense to take our decimal input and
convert it to binary for efficiency reasons.
--
Dan Espen
|
|
|
|
| Re: Where do byte orders come from [message #397005 is a reply to message #396988] |
Fri, 24 July 2020 20:54 |
Robin Vowels
Messages: 426
Registered: July 2012
Karma: 0
|
Senior Member |
|
|
On Saturday, July 25, 2020 at 4:08:27 AM UTC+10, Radey Shouman wrote:
> Peter Flass <p......@yahoo.com> writes:
>
>> Gareth Evans <h......@yahoo.com> wrote:
>>> On 24/07/2020 16:54, John Levine wrote:
>>>> In article <0972e4a9-2307-449f-8d23-......@googlegroups.com>,
>>>> Quadibloc <j......@ecn.ab.ca> wrote:
>>>> > While this page doesn't explain when the decision to include
>>>> > little-endian was
>>>> > made, it does name the originator of the design for the PDP-11: Harold
>>>> > McFarland.
>>>> >
>>>> > https://history-computer.com/ModernComputer/Electronic/PDP-1 1.html
>>>>
>>>> I have been trying for many years to find out why DEC used a
>>>> little-endian byte order in the PDP-11 rather than the big-endian that
>>>> all then-existing byte addressable machine used.
>>>>
>>>> So far nobody has 'fessed up, although lots of people have sent along
>>>> uninformed speculation. I know lots of reasons that DEC might have
>>>> chosen little-endian, but I don't know why they actually did.
>>>>
>>>>
>>>>
>>>
>>> But Little Endian is the obvious and logical approach,
>>> otherwise when dealing with multi precision you have to fart
>>> about to get to the least significant byte when presented
>>> with the address of the variable in memory.
>> No, big-endian is the logical approach for any machine bigger that an 8008,
>> since words are operated on, and brought into the ALU, as a unit.
>> Big-endian is the way people think of numbers, otherwise you’d write
>> amounts like 00.000,1$ for a thousand dollars.
>
> When writing Arabic* that's exactly how it's done. That is, the digit
> order is the same as it is in Latin script, which is opposite the letter
> order for words. Although "arabic numerals" is perhaps a misattribution
> it does seem that that is whence they were adopted by Europeans. It
> seems they just got the endianness wrong -- to be consistent they should
> have reversed the order.
>
> Least significant digit first is also exactly how numbers are written
> when they are being calculated by hand, which was the point of
> zero-based notation in the first place.
ACE and DEUCE held values internally in "Chinese" binary, that it with the
least-significant bit on the left.
Being serial machines, the least-significant bit of a word
emerged first from storage on its way to the adders.
|
|
|
|
| Re: Data General, was Where do byte orders come from [message #397006 is a reply to message #396990] |
Fri, 24 July 2020 21:03 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
Peter Flass <peter_flass@yahoo.com> wrote:
> Jon Elson <elson@pico-systems.com> wrote:
>> John Levine wrote:
>>
>>
>>> The Nova was a very good design for the time. It was straightforward
>>> to program and more importantly, straightforward to manufacture. I
>>> gather it was similar to the rejected PDP-X but not identical, which
>>> isn't surprising since its designers had more time to reconsider and
>>> refine the design.
>>>
>> Having programmed both the Nova and the PDP-11, the PDP-11 was light years
>> ahead of the Nova. The Nova was basically a PDP-8 extended to a 16 bit
>> word. Yes, it had 4 registers, which was a huge improvement over the PDP-8.
>> But, I think the Nova was an indication that DeCastro was stuck in the past,
>> and just wanted to make slight improvements to the PDP-8. The PDP-11 was a
>> bold step into a new way of thinking, a whole new concept of CPU
>> architecture. Hopefully I don't have to detail the differences here.
>> (And, my memory of the Nova has faded largely into the distant past,
>> I last used one 45 years ago!)
>>
>
> Reading Bell’s paper it appears that the Nova was based on the DEC “PDP-X”
> design that was rejected in favor of the PDP-11.
>
Or maybe not-
http://simh.trailing-edge.com/docs/pdpx.pdf
--
Pete
|
|
|
|
| Re: Data General, was Where do byte orders come from [message #397009 is a reply to message #396991] |
Fri, 24 July 2020 22:43 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
|
Senior Member |
|
|
John Levine <johnl@taugh.com> wrote:
> In article <Z96dnZpUvreohobCnZ2dnUU7-YvNnZ2d@giganews.com>,
> Jon Elson <elson@pico-systems.com> wrote:
>>> The Nova was a very good design for the time. It was straightforward
>>> to program and more importantly, straightforward to manufacture. I
>>> gather it was similar to the rejected PDP-X but not identical, which
>>> isn't surprising since its designers had more time to reconsider and
>>> refine the design.
>>>
>> Having programmed both the Nova and the PDP-11, the PDP-11 was light years
>> ahead of the Nova. The Nova was basically a PDP-8 extended to a 16 bit
>> word. Yes, it had 4 registers, which was a huge improvement over the PDP-8.
>> But, I think the Nova was an indication that DeCastro was stuck in the past,
>> and just wanted to make slight improvements to the PDP-8.
>
> I agree the PDP-11 was more fun to program, but the Nova was an
> excellent piece of engineering. It was two large circuit boards that
> pluggeed into a simple backplane so it was cheap and easy to
> manufacture. The Nova shipped in 1969 at a base price of $4K or $8K
> for a usable configuration. The PDP-11/20 shipped a year later priced
> at $20K, partly because it was a more complex design, but also because
> it was built from many small modules that plugged into a custom wired
> backplane.
“Flip Chips?”
>
> Eventually the PDP-11 won as the extra complexity became cheaper to
> implement, and the advantages of byte addressing became more
> compelling, but DG sold a whole lot of computers, mostly through OEMs
> who packaged them into something else so the end customer didn't do
> the programming.
>
> DEC's Omnibus in 1971 was a backplane for the PDP-8/E and DEC came
> up with one for the PDP-11 around 1973.
>
--
Pete
|
|
|
|
| Re: Data General, was Where do byte orders come from [message #397011 is a reply to message #397009] |
Fri, 24 July 2020 23:14 |
|
|
Originally posted by: rnetzlof
On Friday, July 24, 2020 at 10:43:16 PM UTC-4, Peter Flass wrote:
> John Levine wrote:
>> I agree the PDP-11 was more fun to program...
>> ...it was a more complex design, but also because
>> it was built from many small modules that plugged into a custom wired
>> backplane.
> “Flip Chips?”
Not really. Flip Chips was DEC's name for their line of logic boards which became somewhat obsolete when 14 and 16 pin DIP packaged RTL, DTL, and TTL circuits became available. The PDP-11 modules used the same physical board design as the Flip Chips but housed much more complex circuits, designed purely for the PDP-11.
Bob Netzlof
|
|
|
|
|
|
| Re: Where do byte orders come from [message #397019 is a reply to message #396996] |
Sat, 25 July 2020 04:55 |
Quadibloc
Messages: 4399
Registered: June 2012
Karma: 0
|
Senior Member |
|
|
On Friday, July 24, 2020 at 2:00:04 PM UTC-6, Ahem A Rivet's Shot wrote:
> On Fri, 24 Jul 2020 10:32:36 -0700 (PDT)
> Quadibloc <jsavard@ecn.ab.ca> wrote:
>
>> In that case, Big-Endian does not go far enough. Clearly we also have to
>> change computers over from doing their arithmetic in incomprehensible
>> binary to calculating everything in decimal so that the contents of
>> storage will make sense.
>
> Careful now, you'll re-invent ENIAC soon.
Although I did have tongue in cheek as I typed that, it was the IBM 7070 I was
thinking of.
ENIAC is interesting for other entirely different reasons: basically, it's what
we now call a dataflow architecture.
John Savard
|
|
|
|
Members
Search
Help
Register
Login
Home
