CBBS version 3.5, and other musty stuff

[Tom Jennings]

> >From: "Tom Jennings" <tomj at wps.com>
> >Using minicom on linux. XMODEM protocol failed; not sure what
> >the problem is. Possibly minicom's XMODEM doesn't do checksum
> >xmodem, only crc, my program (telink) doesn't do crc. So I did
> >everything as ASCII.


On Fri, 24 Dec 2004, Dwight K. Elvey wrote:
>  I recently used Xmodem from Windoz and found that
> the binaries didn't work with the ascii handshake
> turned on. It worked fine with the setting for no
> handshake at all.

Well, the CP/M side certainly has no protocol issues, the program
talks to the IO port hardware directly:


foo:	in someport
	ani somebit
	jz foo
	mov a, c
	out someotherport
	ret

Minicom has no XON/XOFF, and no hardware handshake, and in any
case, only three wires.


I really think it's code incompatibility. The original xmodem
did checksum per block only; CRC was added later. There's some
trick to autodetect, I forget what it is. My xmodem code is
really old, old enough I had to work the protocol out from
Ward's code; mine's written in BDS C.  (I documented it back
then and will dig up the doc. I probably wasn't the only one
to do this.). It could be simply my xmodem protocol is bad.

It's not really a good way to send the files, but I wanted to
get everything working again.