7 Jan
2005
7 Jan
'05
10:21 a.m.
> disks on the hardware I have here. "Binary
reads from a device are not
> allowed" is the message at 8753 in DR-DOS 3.41.
On Wed, 5 Jan 2005,
Vintage Computer Festival wrote:
The question I haven't seen answered yet is,
"Well, why the hell not???"
Because the ONLY data that it has to determine EOF is the incoming data
stream.
Following in Gary Kildall's footsteps, they chose to use ^Z as an EOF
marker, thereby permanently disabling the capability of using the device
for inputting anything that contains byte 1Ah
When I was writing XenoComm-Parallel, I would have preferred to do it as a
device driver, so that the user could use COPY. Instead, I had to write a
small stand-alone program.
To be able to sense EOF reauires setting aside one bit pattern for an EOF
character,
using a sequence of bytes (how do you transfer the HELP file that lists
them?)
using user intervention ("press the ANY key when it is done")
using a hardware signal outside of the data stream.
I seriously considered using a time-out to trigger EOF detection! (a
generally BAD idea)
My usual machine for internet access just croaked (bad checksum in
NTVDM.EXE), so, I'm using a Chembook notebook that has several
broken keyboard keys, (so I'll have plenty of spelling errs), while I
figure
out how to boot the machine well enough
to fix it.
--
Grumpy Ol' Fred cisin(a)xenosoft.com