19 Nov
2005
19 Nov
'05
6:50 a.m.
I have a chart of paper tape hole patterns for all 128 characters, and it
shows the LSB (bit zero, although the chart numbers them 1-8) as the edge
hole on the 3-hole side, with the bits in order 0 to 7 (or 1 to 8).
However, one question, this chart shows the high-order bit (parity bit)
punched for every character, no exceptions. Was that a standard convention
in sending ascii files to paper tape?
19 Nov
19 Nov
6:58 a.m.
>>>> "Barry" == Barry Watzman
<Watzman at neo.rr.com> writes:
Barry> However, one question, this chart shows the high-order bit
Barry> (parity bit) punched for every character, no exceptions. Was
Barry> that a standard convention in sending ascii files to paper
Barry> tape?
You mean the high order bit was always on -- as opposed to being a
parity bit? That's unusual. Parity is a bit more common, but I don't
think there was a single standard. Classic ASCII is a 7-bit code,
leaving the 8th bit for people to mess with as they saw fit.
paul
7:28 a.m.
There are 4 parity states.
Mark parity = always punched
Space parity = never punched
Odd & even = punching based on other 7 bits of data
and None = all 8 bits are data.
Bob
On Sat, 19 Nov 2005 09:50:58 -0500, Barry Watzman wrote:
I have a chart of paper tape hole patterns for all 128
characters, and it
shows the LSB (bit zero, although the chart numbers them 1-8) as the edge
hole on the 3-hole side, with the bits in order 0 to 7 (or 1 to 8).
However, one question, this chart shows the high-order
bit (parity bit)
punched for every character, no exceptions. Was that a standard convention
in sending ascii files to paper tape?
6975
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6975
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2 comments
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participants (3)
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Bob＠BRADLEE.ORG -
pkoning＠equallogic.com -
Watzman＠neo.rr.com