On Sat, 24 Feb 2007, Lawrence Wilkinson wrote:
I can't remember exactly how it did this, maybe it
did a COPY COM1
and had a bootstrap that would copy over a 7-bit link.
You could use this method to enter in a larger program, by dumping it in
hex, converting it to a DEBUG script with lots of E commands and then
pushing it in (assuming you have DEBUG available).
7 bit is correct. The DOS COPY command refuses to COPY a "binary" file
from a device. There is even an error message stating
that in COMMAND.COM
. Therefore, it is necessary that the stage of the
bootstrapping that uses COPY must be a text[able] file. Fortunately, a
program that will "copy" from a device does not need to be very long.