On Tue, Jun 01, 2004 at 04:41:49PM -0700, Tom Jennings wrote:
> On Tue, 2004-06-01 at 14:00, Gene Buckle wrote:
> > I had one of those when I was in high school. It was a Terminet 300 and
> > didn't have any keyboard attached to it. Right after I got it (in trade
> > for a wrecked R/C helicopter of all things), I loaned it to a friend that
> > discovered the hard way that Form Feed _really_ meant Feed All 2500 Sheets
> > of Paper Out of The Box And On To The Floor. He wasn't amused. :)
>
> You merely needed to punch a new VFU tape on your paper tape punch....
That's like a great "bug" in bisync protocols - you could instruct the
printer to "skip to channel n", meaning do linefeeds until there was a
hole in the nth channel on the VFU tape. By convention, channel 1 was
always punched to the top of form - issuing a "skip to channel 1" was
the HASP/3780 equivalent of an ASCII FF.
The bug is that the communication protocol allows your program to issue
a "skip to channel 0" command to the printer - but there _is_ no channel
zero on a 12-channel paper tape. Newer devices treat channel 0 as if
it were channel 1. Older, especially mechanical devices with real VFU
tapes, empty the box of paper, waiting for a non-existent channel to
respond.
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 02-Jun-2004 01:30 Z
South Pole Station
PSC 468 Box 400 Temp -89.7 F (-67.5 C) Windchill -136.7 F (-93.7 C)
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Ethan.Dicks_at_amanda.spole.gov http://penguincentral.com/penguincentral.html
Received on Tue Jun 01 2004 - 20:48:27 BST