Knuth's MIX i/o unit 19: typewriter and paper tape

I'm a little confused by the MIX i/o unit 19 in vol.1 of Knuth's Art
of Computer Programming, pp.132-134. The unit is described as a
"Typewriter and paper tape", with a block size of 14 words.

I don't really understand what the unit is. If I were to guess, I would
guess that it consists of two items, one of which is used for input and
the other for output, i.e. the typewriter for output and the paper tape
for input. Is that correct?

Assuming that it is, what facilities does MIX offer for writing programs
to a paper tape? Am I correct in further guessing that the typewriter has
an attachment which let's a human typist type programs into a paper tape?

Where are old peripherals like that explained?

Ignorantly,
Allan Adler
ara (AT) zurich (DOT) ai.mit.edu

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Allan Adler writes:

I'm a little confused by the MIX i/o unit 19 in vol.1 of Knuth's Art
of Computer Programming, pp.132-134. The unit is described as a
"Typewriter and paper tape", with a block size of 14 words.

I don't really understand what the unit is. If I were to guess, I would
guess that it consists of two items, one of which is used for input and
the other for output, i.e. the typewriter for output and the paper tape
for input. Is that correct?

Assuming that it is, what facilities does MIX offer for writing programs
to a paper tape? Am I correct in further guessing that the typewriter has
an attachment which let's a human typist type programs into a paper tape?

Where are old peripherals like that explained?

The back flyleaf of Volume I lists IN and OUT as instructions and IN is
described on page 132 and seems to be what you want so I suppose OUT is too.

I hate MIX and wish he would spend his remaining time replacing it with
pseudocode and come up with MIX less versions of the current volumes. Since
HE already knows MIX, I suspect I have a lost cause on my hands since there
is no reason to believe he does this for the money. Actually, I think most
writers don't do it for the money.

On 13 Nov 2003 00:56:20 -0500, Allan Adler <ara (AT) nestle (DOT) ai.mit.edu>
wrote:

I'm a little confused by the MIX i/o unit 19 in vol.1 of Knuth's Art
of Computer Programming, pp.132-134. The unit is described as a
"Typewriter and paper tape", with a block size of 14 words.

I don't really understand what the unit is. If I were to guess, I would
guess that it consists of two items, one of which is used for input and
the other for output, i.e. the typewriter for output and the paper tape
for input. Is that correct?

Chances are he had a teletype in mind. There would have been a
typewriter and paper tape reader/punch in the same unit, with a serial
connection to the computer. When the tape was turned on, anything
typed or received on the serial connection was both printed on a roll
of paper and punched on the tape. Conversely, reading a punched tape
caused symbols to be printed on the paper and sent to the computer.
The serial connection could also be to a modem - in fact most teletype
were used to send text messages over phone lines.

Assuming that it is, what facilities does MIX offer for writing programs
to a paper tape? Am I correct in further guessing that the typewriter has
an attachment which let's a human typist type programs into a paper tape?

Where are old peripherals like that explained?

Here's one place: http://www.columbia.edu/acis/history/teletype.html

--
Al Balmer
Balmer Consulting
removebalmerconsultingthis (AT) att (DOT) net

On Thu, 13 Nov 2003 07:31:50 -0800, osmium wrote:

Allan Adler writes:

I'm a little confused by the MIX i/o unit 19 in vol.1 of Knuth's Art
of Computer Programming, pp.132-134. The unit is described as a
"Typewriter and paper tape", with a block size of 14 words.

I don't really understand what the unit is. If I were to guess, I would
guess that it consists of two items, one of which is used for input and
the other for output, i.e. the typewriter for output and the paper tape
for input. Is that correct?

Assuming that it is, what facilities does MIX offer for writing programs
to a paper tape? Am I correct in further guessing that the typewriter has
an attachment which let's a human typist type programs into a paper tape?

Where are old peripherals like that explained?

The back flyleaf of Volume I lists IN and OUT as instructions and IN is
described on page 132 and seems to be what you want so I suppose OUT is too.

I hate MIX and wish he would spend his remaining time replacing it with
pseudocode and come up with MIX less versions of the current volumes.

He has already created MMIX to replace MIX, and does plan to produce
MMIX versions of the current volumes. Of course, MMIX is still assembly
language...

osmium wrote:

.... snip ...
is no reason to believe he does this for the money. Actually, I
think most writers don't do it for the money.

But, if they are successful and popular, my god how the money
rolls in :-)

--
Chuck F (cbfalconer (AT) yahoo (DOT) com) (cbfalconer (AT) worldnet (DOT) att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!

On Thu, 13 Nov 2003 18:13:31 GMT, CBFalconer <cbfalconer (AT) yahoo (DOT) com>
wrote:

osmium wrote:

... snip ...
is no reason to believe he does this for the money. Actually, I
think most writers don't do it for the money.

But, if they are successful and popular, my god how the money
rolls in :-)

Yep. The story is that he got a royalty of about $4.00/copy, and the
publisher figured to sell a few thousand. The first edition sold more
than a million.

That doesn't happen to software geeks often enough :-)

--
Al Balmer
Balmer Consulting
removebalmerconsultingthis (AT) att (DOT) net