[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: What are the 94 printable characters from the 128 characters of ASCII table?




On Jul 26, 2011 12:51 AM, "Bob Proulx" <bob@proulx.com> wrote:
>
> Paul E Condon wrote:
> > but 2 are non printing: 0x20 and 0x7F
> > I leave the last step as an exercise for the reader. ;-)
>
> I hate to make this thread longer...  Sigh.
>
> Whether something is printable or not was easier to see in the old
> days when printers had dot matrix or daisy wheels or selectric balls
> or other such loud and visible print heads.  If you emitted a
> printable character the head moved forward.  If you emited a
> non-printable character the head did not move forward.
>
> Using that definition space is definitely a printable character since
> it moves the print head forward.  We are all agreed that it is
> invisible.  But being invisible is not part of the definition of
> whether it is printable or not.
>

Ummm, earlier printers than that didn't have moveable heads like that. There was this printer that used a chain with a few sets of letters and 80 hammers. When the right letter moved under the proper hammer, it fired (and if you asked it to print a row with letters in the 'right' order, the chain would snap). Point being, a 'head' didn't move to create a space, so that logic is flawed.

I also don't think space is printable but whatever.


Reply to: