[Coco] Serial Connection from Linux to CoCo3

gene heskett gheskett at wdtv.com
Sat Dec 4 20:21:31 EST 2010


On Saturday, December 04, 2010 08:04:35 pm Don Johnson did opine:

> On 2010-12-04, at 1:44 PM, Bob Devries wrote:
> > ----- Original Message ----- From: "Don Johnson"
> > <coco at fivejohnsons.com> To: "CoCoList for Color Computer Enthusiasts"
> > <coco at maltedmedia.com> Sent: Sunday, December 05, 2010 7:16 AM
> > Subject: [Coco] Serial Connection from Linux to CoCo3
> > 
> >> I've grabbed this out the Glenside IDE booting problems thread so it
> >> has it's own interest.
> >> 
> >> On 2010-12-03, at 4:18 PM, gene heskett wrote:
> >> 
> >> ---snip---
> >> 
> >> I am still getting  the cables and converters to add a 5.25" drive to
> >> my Linux box for direct copy of the Nitros .dsk images to a floppy,
> >> but in the mean time I am attempting this connection and have some
> >> questions...
> >> 
> >>>>> If it helps any, my web pages have disk images that IF you have a
> >>>>> floppy controller, something like the linux 'dd' command can write
> >>>>> these to a 3.5" or 5.25" 360k floppy disk.  Various operating
> >>>>> systems have various tools for this.  For my own lashup here, my
> >>>>> ASUS motherboards floppy controller does not do 256 byte/sector
> >>>>> disk formats, so I am forced to run a session of minicom on this
> >>>>> linux box, to a shell running against my deluxe 232 pack, so I am
> >>>>> logged into the coco from here, and can then run rz/sz to move
> >>>>> this stuff back and forth.
> >>>> 
> >>>> Okay this may have potential as I do have a mini232 pack here from
> >>>> CoNect that I can use.  Of course I have no experience in this form
> >>>> of communication between a Linux box and the CoCo3, but I should
> >>>> have all the parts.   I different task than this thread, but do
> >>>> you have any instructions on how you set this up?
> >> 
> >> As a preface:  I have put my Mini232 pak into slot 1 of the MPI and
> >> connected it with a serial cable, null modem, and DB25 to DB9
> >> adapter to the Linux box.  I am running Ubuntu 10.10 on the LInux
> >> box, and for interests sake I have found the port at /dev/ttyS0.
> >> 
> >> I am not currently running Nitros9, just OS-9 Level II.
> >> 
> >>> Set both interfaces to 9600 baud,
> >> 
> >> done
> >> 
> >>> start a "shell -i /t2 &" w/o the quotes
> >>> on the coco,
> >> 
> >> done
> >> 
> >>> install minicom on the linux box, run it with "minicom -s",
> >> 
> >> done
> >> 
> >>> find the modem strings section and zero that out
> >> 
> >> done.  Set the init string to "0", set the reset string to "0".  Not
> >> sure if that is what you meant, but erasing everything didn't have
> >> the same success in seeing a online status.  I might have changed
> >> things sense I did this that may have resulted in the success, but
> >> unless I have reason to believe otherwise I have saved these two
> >> settings as default as I did get a limited amount of success.
> >> 
> >>> , then select the linux port
> >>> (you'll have to be root to access the port).
> >> 
> >> done, and tested (got the right port :) )
> >> 
> >>> You will probably want to
> >>> also set minicom to make it use the coco's cr as a lf and vice
> >>> versa, should be in the port config menu's someplace.
> >> 
> >> I think this is in the macro settings, but not sure if I have the
> >> correct macro set up.
> >> 
> >>> If successful after exiting the config stuff (save it when it works)
> >>> then you should see a prompt from the coco that resembles this when
> >>> the enter key is pressed on your keyboard:
> >> 
> >>> {t2|07}/DD/NITROS9/3.2.9:
> >> Okay now this is not happening.  I see no prompt, but I do have the
> >> status bar saying I am online, which also tells me how many minutes
> >> I have been online.  Now I know I am connected because if I
> >> interrupt the shell on the CoCo3 and direct a command to the /T2
> >> device it will appear on the minicom screen, but I can't seem to get
> >> a prompt or anything on the minicom when I simply direct the shell
> >> to /T2.  Typing an OS-9 command on the minicom screen will also, not
> >> get a response, which does not surprise me because I have no prompt,
> >> but I thought it would be worth a shot.
> > 
> > Don, sounds like you have everything right at first glance.
> > 
> > One thing that is absolutely necessary is that the hardware
> > handshaking is "defeated" the null modem cable must loop back the
> > various handshake signals, or else your PC (and Windows is the same
> > for this) will not talk to your coco.
> > 
> > Regards, Bob Devries
> 
> I didn't trust my null modem adapter so I made my own null modem serial
> cable, out of a serial cable I had lying around, with the loop back
> handshaking.  Still got the same affect though.
 
Unfortunately, there seems to be about as many 'variations' of a null modem 
cable as there are cable peddlers about.  Google for drawings and go stark 
raving nuts trying to figure out what you need.

I have one of those rs-232 sniffers with the multicolored leds to tally the 
state of the lines, and its sitting here with all the leds green except the 
two data lines, which are solid red when there is no traffic flowing.  That is 
something else the shack _used_ to sell, and its as handy as the turn 
button on the outhouse door.

Probably available on the internet from several suppliers even if the shack 
hasn't had one in a decade.  I have so many cables in series, some of which 
are home made too, that without that to help keep me straight, I'd give up.  
The main link is actually a 20 foot length of cat-5 I put db-9's on this 
end, and a db-25 on the other.  I should have made it 10 feet longer and I 
could then do away with one of the extensions thats db-09 on both ends.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Krogt, n. (chemical symbol: Kr):
	The metallic silver coating found on fast-food game cards.
		-- Rich Hall, "Sniglets"



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