Importing binary files without removable storage nor non-bundled software (was: TKermitFTP

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Wed Jan 5 16:27:52 2005

> > In the case of DOS 6.22, the message "Cannot do binary reads from a
> > device" is at offset 970F in COMMAND.COM
On Tue, 4 Jan 2005, Tom Jennings wrote:
> Sheesh, it only took them 10 years to declare it impossible and
> test for the error.

Well, ...
in DOS 4.00, it is at offset 7CCC. It may have been there since QDOS?
Although admittedly, I do not know whether earlier versions actually
included the test for the error to DISPLAY the message.
Perhaps some with older DOS currently installed could try:
COPY /B CON: filename
to see whether it notices?


But use of the built-in DOS device drivers in order to use COPY /B is NOT
the only way.

PC-DOS 3.30 (but probably NOT MS-DOS 3.30) has REC35.COM bundled
with DOS. That was mostly because IBM started using 3.5" drives on PS/2
WITHOUT usually having a 5.25" drive present, and needed a way to do
format conversion.


Or,...
you could write and debug a small bootstrap program for loading a binary
file through a port. [Left as an exercise for the reader]

The "operator" of the machine can then type it into DEBUG
or,...
Disassemble it into a text file of the source code with no labels,
comments, etc. insert an "A <crlf>" at the beginning, and add at the end:
N filename <crlf>
R CX nnnn <crlf>
W <crlf>
Q <crlf>

For example:
A
JMP 106
DB 1A
DB 1A
DB 1A
DB 1A
MOV AH, 2
MOV DL, 42
INT 21
INT 20
N test.com
R CX E
W
Q

COPY that text file (yes, you can do it /A) into the machine, with a
filename on the order of TESTCODE.DAT
Have the "operator" of the machine type
DEBUG < TESTCODE.DAT <crlf>

It will produce a .COM file that CAN include ^Z characters.

One of the computer magazines (PC? PCWORLD?) used that briefly
as a way to distribute programs to their readers, some of whom
could not have managed without it. Another way they did it was
as DATA statements in a BASIC program.
The redirection into DEBUG has the advantage of not hiding the code
as thoroughly, and thus being less insulting to our intelligence.

--
Grumpy Ol' Fred     		cisin_at_xenosoft.com
Received on Wed Jan 05 2005 - 16:27:52 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:37:43 BST