13 Jan
2011
13 Jan
'11
6:32 a.m.
? There are no Teletypes that use Baudot code. They use a US variant of
? the ITA2 five-level code.
? Baudot code was only used until about 1901. Murray code was used until
? the 1930s. Everything after that used ITA2.
That's a little like saying nobody actually uses ASCII since 1968, we're all
really
Using ANSI_X3.4-1968 or later. Technically true but not common usage.
Everyone in the past half century has called a Model 28 TTY a Baudot Teletype when
They had to distinguish it from any other type. (Baudot is still the default for
Several applications so you don't even have to say it's Baudot.)
I suppose classiccmp naturally attracts folks who care about such things (witness
The thread I started over a few years ago when I noted that bitsavers had surpassed
100 GBytes and everyone informed me that no, a Gbyte was 1073741824 bytes so
I was wrong.)
Tim.
13 Jan
13 Jan
6:56 a.m.
On Thu, Jan 13, 2011 at 09:32:48AM -0500, Shoppa, Tim wrote:
??? There are no Teletypes that use Baudot code. They
use a US variant of
??? the ITA2 five-level code.
??? Baudot code was only used until about 1901. Murray code was used until
??? the 1930s. Everything after that used ITA2.
That's a little like saying nobody actually uses ASCII since 1968, we're all
really
...
I suppose classiccmp naturally attracts folks who care
about such things (witness
It's a list of pedants, which is actually quite fine with me.
It was interesting to me hearing it was actually ITA2 five-level code in
some circles. Just learn to smile and nod a lot and it's fine. ;-)
Tim.
- Diane
--
- db at FreeBSD.org db at db.net http://www.db.net/~db
7:23 a.m.
On 1/13/11 9:32 AM, Shoppa, Tim wrote:
? There are no Teletypes that use Baudot code. They
use a US variant of
? the ITA2 five-level code.
? Baudot code was only used until about 1901. Murray code was used until
? the 1930s. Everything after that used ITA2.
That's a little like saying nobody actually uses ASCII since 1968, we're all
really
Using ANSI_X3.4-1968 or later. Technically true but not common usage.
Heh, or EIA-232D vs. RS-232. (RS == "Recommended Standard")
-Dave
--
Dave McGuire
Port Charlotte, FL
6:08 p.m.
On Thursday (01/13/2011 at 10:23AM -0500), Dave McGuire wrote:
On 1/13/11 9:32 AM, Shoppa, Tim wrote:
You know, that RS-232 that comes straight out of a microcontroller's
UART at 3.3v or 1.8v swings... that RS-232.
--
Chris Elmquist
? There are no Teletypes that use Baudot code.
They use a US variant of
? the ITA2 five-level code.
? Baudot code was only used until about 1901. Murray code was used until
? the 1930s. Everything after that used ITA2.
That's a little like saying nobody actually uses ASCII since 1968, we're all
really
Using ANSI_X3.4-1968 or later. Technically true but not common usage.
Heh, or EIA-232D vs. RS-232. (RS == "Recommended Standard") 
14 Jan
14 Jan
noon
Chris Elmquist wrote:
For input (ASR33 to microcontroller) you might get away with it -- after
all the trasnmit loop of the ASR33 is just switch contacts. Although for
some contacts having too low a voltage can prevent them self-cleaning
properly.
For output (microcontroller to ASR33), well 'You cna try it if you like
but you'd far better not-a'. I doubt the ASR33 would mind a bit, though
:-)
-tony
You know, that RS-232 that comes straight out of
a microcontroller's
UART at 3.3v or 1.8v swings... that RS-232.
Cool! That means I can connect it directly to my ASR33!
11:55 a.m.
You know, that RS-232 that comes straight out of a
microcontroller's
UART at 3.3v or 1.8v swings... that RS-232.
Ah yes, anotehr of my pet hates... People who equate asynchronous serial
communications with RS232. There are of course plenty of asynchronosu
data transmission systems which do not use RS232 levels (like te output
of a microcomntroller [1]) and there are plenty of RS232 interaces that
are synchronous.
Equating 'serial port' with either of them annoys me. Particularly people
who don't accept that USGB, I2C, SPI, floppy disk data, etc are all seiral
interfaces.
[1] Of course my first thought for that would be a 5V swing...
-tony
4:04 p.m.
On 14 Jan 2011 at 19:55, Tony Duell wrote:
Equating 'serial port' with either of them
annoys me. Particularly
people who don't accept that USGB, I2C, SPI, floppy disk data, etc are
all seiral interfaces.
[1] Of course my first thought for that would be a 5V swing...
What we commonly knew as a "serial mouse" apparently has shifted
meaning. I was shopping around to see if anyone still made "combo
mice" with PS/2 and RS-232C interfaces.
"Serial" apparently now means USB. Okay, but XT, AT, PS/2, RS232C
and USB are all "serial".
--Chuck
15 Jan
15 Jan
10:02 a.m.
What we commonly knew as a "serial mouse"
apparently has shifted
meaning. I was shopping around to see if anyone still made "combo
mice" with PS/2 and RS-232C interfaces.
"Serial" apparently now means USB. Okay, but XT, AT, PS/2, RS232C
and USB are all "serial".
Last time I bought a mouse (which was only a couple of months ago), the
ones in the local Maplin were labelled as 'USB' or 'PS/2' on the box. Als
on RS232 seiral ones at all.
Not hat it mattered for what I wanted. I didn't want a mouse at all. I
wanted a dual phototransitor to fix a shaft encoder, and a cheap PC mouse
was the easies way to get it.
I would argue that quadrature mice are not serial but prallel in that the
states of the 4 quadrature signasl and the <n> buttons are all available
simultaneously on the interfce connector. Yes, you have to look for
changes in signals to see if/how the mouse is moving, but I don;t think
that makes it serial.
Mind you, I am old enough to rememebr descriptions like 'bit parallel,
characger serial' for the Centronics interface, meaning that while all
the bits of a given character are presented in parallel, the characters
of a line are sent one after another -- serially. I also remember digital
measuring instruments with a fully parallel BCD interface, whiuch would
have perhaps 32 data lines for the 4 bit BCD of each of the 8 digits. All
valid at the same time/.
-tony
11:02 a.m.
On 15 Jan 2011 at 18:02, Tony Duell wrote:
I would argue that quadrature mice are not serial but
prallel in that
the states of the 4 quadrature signasl and the <n> buttons are all
available simultaneously on the interfce connector. Yes, you have to
look for changes in signals to see if/how the mouse is moving, but I
don;t think that makes it serial.
Perhaps, but when was the last time that you saw a new quadrature
mouse being offered for sale? Mice today universally communicate
using a single serial bit stream.
--Chuck
1:39 p.m.
On 15 Jan 2011 at 18:02, Tony Duell wrote:
I am pretty sure I've seen new quadrature-output trackballs farily
recently. Not quite the same thing, but much the same interface...
I would argue that quadrature mice are not serial
but prallel in that
the states of the 4 quadrature signasl and the <n> buttons are all
available simultaneously on the interfce connector. Yes, you have to
look for changes in signals to see if/how the mouse is moving, but I
don;t think that makes it serial.
Perhaps, but when was the last time that you saw a new quadrature
mouse being offered for sale? Mice today universally communicate using a single serial bit stream.
This is classiccmp, right? I think more of my machines take
qudrature-ouptut mice than take serial mice (and of the latter, most of
them are HP-HIL interfaced mice, which is a bit-serial interface).
-tony
14 Jan
14 Jan
4:57 p.m.
On Friday (01/14/2011 at 07:55PM +0000), Tony Duell wrote:
well, it was mine too... but I was trying to be "hip". When I go to
work each day now, I have to leave at least 1.7v at home.
--
Chris Elmquist
You know, that
RS-232 that comes straight out of a microcontroller's
UART at 3.3v or 1.8v swings... that RS-232.
Ah yes, anotehr of my pet hates... People who equate asynchronous serial
communications with RS232. There are of course plenty of asynchronosu
data transmission systems which do not use RS232 levels (like te output
of a microcomntroller [1]) and there are plenty of RS232 interaces that
are synchronous.
Equating 'serial port' with either of them annoys me. Particularly people
who don't accept that USGB, I2C, SPI, floppy disk data, etc are all seiral
interfaces.
[1] Of course my first thought for that would be a 5V swing... 
1:59 a.m.
On Thu, 13 Jan 2011, Dave McGuire wrote:
Or V.24 vs. (whatever)-232... E.g. the ASR33 is not RS-232 but definitely
V.24; the same applies to a DE9 PC "serial port".
Christian
Using
ANSI_X3.4-1968 or later. Technically true but not common usage.
Heh, or EIA-232D vs. RS-232. (RS == "Recommended Standard") 
3:23 a.m.
Christian Corti wrote:
E.g. the ASR33 is not RS-232 but definitely V.24;
The Teletype Model 33 ASR may or may not meet V.24, depending on how it
is wired. There are a *lot* of different ways to wire it.
the same applies to a DE9 PC "serial port".
The DE9 PC serial port meets the EIA/TIA-232 standard electrical
characteristics (if the board is designed properly), and TIA-574
standard connector.
1 p.m.
On 14/01/2011 11:23, Eric Smith wrote:
Christian Corti wrote:
<grin> It would be more accurate to say that TIA-574 meets the DE9 PC
serial port "standard" (or non-standard), as the TIA standard postdates
the PC use by many years. Before that, most DE9 serial ports were wired
like microVAXen.
--
Pete Peter Turnbull
Network Manager
University of York
E.g. the ASR33 is not RS-232 but definitely V.24;
The Teletype Model 33 ASR may or may not meet V.24, depending on how it
is wired. There are a *lot* of different ways to wire it.
the same applies to a DE9 PC "serial
port".
The DE9 PC serial port meets the EIA/TIA-232 standard electrical
characteristics (if the board is designed properly), and TIA-574
standard connector. 
3:20 p.m.
On Fri, 14 Jan 2011, Christian Corti wrote:
Or V.24 vs. (whatever)-232... E.g. the ASR33 is not
RS-232 but definitely
V.24; the same applies to a DE9 PC "serial port".
I remember the manager of a Radio-Shack "Computer Store" telling us that
the DIN connector on the Coco was "RS-232 - Radio Shack 232". No, he did
NOT know that that was not the canonical use of "RS".
--
Grumpy Ol' Fred cisin at xenosoft.com
13 Jan
13 Jan
1:26 p.m.
I wrote:
? There are no Teletypes that use Baudot code. They use a US variant of
? the ITA2 five-level code.
? Baudot code was only used until about 1901. Murray code was used until
? the 1930s. Everything after that used ITA2.
Tim wrote:
That's a little like saying nobody actually uses
ASCII since 1968,
we're all really
Using ANSI_X3.4-1968 or later. Technically true but
not common usage.
No, it's not much like that at all. Baudot code used significantly
different character encodings than ITA2, such that a Baudot device and
an ITA2 device will not interoperate in any meaningful fashion.
ASCII-63, ASCII-67, ASCII-68, and ANSI X3.4 have only minor variations
and will generally interoperate reasonably well.
Look at the following rows that enumerate the character encodings, and
tell me that a Baudot teleprinter can usefully communicate with a
teleprinter using ITA2 or US TTY code. The figures shift and letters
shift codes aren't even the same! ITA2 is obviously derived from
Murray, and to a first glance, it might look like Murray would
interoperate with ITA2 or US TTY, but the letters shift is still in the
wrong place.
Baudot letters: u A E E I O U Y f J G H B C F D
l C X Z S T W V u K M L R Q Z P
figures: u 1 2 & 3 4 O 5 f 6 7 H 8 9 F 0
l . , : ; ! ? ' u ( ) = - / # %
Murray letters: b E j A l S I U c D R J N F C K
T Z L W H Y P Q O B G f M X V d
figures: b 3 j u l ' 8 7 c u 4 u - u ( u
5 . / 2 u 6 0 1 9 ? u f , # ) d
ITA2 letters: b E j A s S I U c D R J N F C K
T Z L W H Y P Q O B G f M X V l
figures: b 3 j - s ' 8 7 c w 4 g , u : (
5 + ) 2 u 6 0 1 9 ? u f . / = l
US TTY letters: b E j A s S I U c D R J N F C K
T Z L W H Y P Q O B G f M X V l
figures: b 3 j - s g 8 7 c $ 4 ' , ! : (
5 " ) 2 # 6 0 1 9 ? & f . / ; l
l letters shift
f figures shift
b blank
c carriage return
j line feed
s space
u undefined or variant graphics
w who are you
g bell
d delete
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17 comments
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participants (10)
-
ard＠p850ug1.demon.co.uk -
cc＠informatik.uni-stuttgart.de -
cclist＠sydex.com -
chrise＠pobox.com -
cisin＠xenosoft.com -
db＠db.net -
eric＠brouhaha.com -
mcguire＠neurotica.com -
pete＠dunnington.plus.com -
tshoppa＠wmata.com