9 Sep
2022
9 Sep
'22
1:33 a.m.
I heard that the IBM 709
series had 36 bit words because Arthur Samuel,
then at IBM, needed 32 bits to identify the playable squares on a
checkerboard, plus some bits for color and kinged
To be precise, Samuel's checkers program was written for
the 701, which originated the architecture that the 709 inherited.
Note that IBM punched cards had 72 data columns plus 8
columns typically dedicated to sequence numbers. 700-series
machines supported binary IO encoded two words per row, 12
rows per card--a perfect fit to established technology. (I do
not know whether the fit was deliberate or accidental.)
As to where the byte came from, it was christened for the IBM
Stretch, aka 7020. The machine was bit-addressed and the width
of a byte was variable. Multidimensional arrays of packed bytes
could be streamed at blinding speeds. Eight bits, which synced
well with the 7020's 64-bit words, was standardized in the 360
series. The term "byte" was not used in connection with
700-series machines.
Doug
9 Sep
9 Sep
2:12 a.m.
New subject: Does anybody know the etymology of the term "word" as in collection of bits?
On Thu, Sep 08, 2022 at 09:33:42PM -0400, Douglas McIlroy wrote:
As to where the byte came from, it was christened for
the IBM
Stretch, aka 7020. The machine was bit-addressed and the width
of a byte was variable.
Huh, I did a lot of the Unix port to the ETA-10, that was the only
machine that I encountered that had bit pointers. I never understood
why that was a thing, Doug, do you know the rationale for bit pointers?
The ETA-10 is not well known, I was part of the Lachman group:
https://en.wikipedia.org/wiki/ETA10
My first job after school, I got to watch Neil toggle in the bootstrap
stuff at the console. He wasn't Seymour but he was very very good.
One of the more substantial people I've ever met, I would guess he
has passed but if he hasn't, he would like this group of people.
Whatever, Doug or anyone, why do bit pointers make sense? Why?
13 Sep
13 Sep
2:23 p.m.
New subject: Does anybody know the etymology of the term "word" as in collection of bits?
At 09:12 PM 9/8/2022, Larry McVoy wrote:
My first job after school, I got to watch Neil toggle
in the bootstrap
stuff at the console. He wasn't Seymour but he was very very good.
One of the more substantial people I've ever met, I would guess he
has passed but if he hasn't, he would like this group of people.
He passed away in 2007:
https://www.msthalloffame.org/neil_robert_lincoln.htm
Lincoln died on Jan. 26, 2007, at age 69. He was a member of the American
Institute of Astronautics and Aeronautics and holds nine U.S. patents for
computer hardware. He was a Distinguished Lecturer of the Institute of
Electronics and Electrical Engineers, a National Lecturer of the
Association for Computer Machinery and on the Advisory Committee
on Science and Technology Centers for the National Science Foundation.
- John
9 Sep
9 Sep
2:45 a.m.
New subject: Does anybody know the etymology of the term "word" as in collection of bits?
There is a certain amount of "use makes master" about word and byte length.
I think DECs decision to go with 6bit for 36bit was probably fine, in the
context of belief around BCD. That it turned out to be a royal pain in the
neck for an 8 byte world was a bit overblown given its time and place.
People found ways to exploit 4 extra bits in a word to do things. DEC
provided the UUO mechanism, people coded odd things into it. If BCD had
been more significant who knows how long packed ASCII might have lasted.
The entire field from bletchley onwards was full of arch, fey witticisms
about machine names. ending things with -AC (for automatic computer) led to
SILLIAC in Sydney Uni and there was a sort of poem which included them all
to MANIAC. I can't but think the neologism byte over 'bite sized chunks of
a whole word' goes directly to this tendency to play with language. And,
the times were ones with many strange players on many continents, fertile
ground for wordplay.
8 is a useful number. 5 hole Baudot wasn't enough: with parity and cases
and control signal in band data was heading to 8 irrespective.
Aligning data with memory and registers makes sense.
On Fri, Sep 9, 2022 at 9:35 AM Douglas McIlroy <
douglas.mcilroy(a)dartmouth.edu> wrote:
I heard that the IBM 709
series had 36 bit words because Arthur Samuel,
then at IBM, needed 32 bits to identify the playable squares on a
checkerboard, plus some bits for color and kinged
To be precise, Samuel's checkers program was written for
the 701, which originated the architecture that the 709 inherited.
Note that IBM punched cards had 72 data columns plus 8
columns typically dedicated to sequence numbers. 700-series
machines supported binary IO encoded two words per row, 12
rows per card--a perfect fit to established technology. (I do
not know whether the fit was deliberate or accidental.)
As to where the byte came from, it was christened for the IBM
Stretch, aka 7020. The machine was bit-addressed and the width
of a byte was variable. Multidimensional arrays of packed bytes
could be streamed at blinding speeds. Eight bits, which synced
well with the 7020's 64-bit words, was standardized in the 360
series. The term "byte" was not used in connection with
700-series machines.
Doug 
16 Sep
16 Sep
5:55 a.m.
New subject: Does anybody know the etymology of the term "word" as in collection of bits?
BTW, IBM’s “Computer Museum” has (had?) a (the?) Stretch and Harvest. The
“museum” is a warehouse full of old stuff.
On Thu, Sep 8, 2022 at 9:35 PM Douglas McIlroy <
douglas.mcilroy(a)dartmouth.edu> wrote:
--
=====
nygeek.net
mindthegapdialogs.com/home <https://www.mindthegapdialogs.com/home>
I heard that
the IBM 709
series had 36 bit words because Arthur Samuel,
then at IBM, needed 32 bits to identify the playable squares on a
checkerboard, plus some bits for color and kinged
To be precise, Samuel's checkers program was written for
the 701, which originated the architecture that the 709 inherited.
Note that IBM punched cards had 72 data columns plus 8
columns typically dedicated to sequence numbers. 700-series
machines supported binary IO encoded two words per row, 12
rows per card--a perfect fit to established technology. (I do
not know whether the fit was deliberate or accidental.)
As to where the byte came from, it was christened for the IBM
Stretch, aka 7020. The machine was bit-addressed and the width
of a byte was variable. Multidimensional arrays of packed bytes
could be streamed at blinding speeds. Eight bits, which synced
well with the 7020's 64-bit words, was standardized in the 360
series. The term "byte" was not used in connection with
700-series machines.
Doug
582
days inactive
589
days old
4 comments
5 participants
participants (5)
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Douglas McIlroy -
George Michaelson -
John Foust -
Larry McVoy -
Marc Donner