[9fans] Anyone awake?

[9fans] Anyone awake?

[northern snowfall]

Hey all,
	I went to a computer show tonight and found a
MiniDIN8 -> DB25 cable for a Macintosh. Since my partner-
in-crime is away mountain climbing, I have no idea how
to set this up.

	Google searches only reveal documentation on
setting up serial consoles on the server side, not the
client side. I'm planning on using an IBM PC (either plan9
or UNIX) as the terminal. Can anyone give me any pointers
on how to set this up?

	Since the cable is DB25, I'm lookin' at using my
parallel port. Is that even possible, to simulate a serial
console over the parallel? Or, am I looking at using another
adapter to connect the parallel to serial?

Thanks, as always,

Don

http://www.7f.no-ip.com/~north_

Re: [9fans] Anyone awake?

[boyd, rounin]

> Since the cable is DB25, I'm lookin' at using my
> parallel port. Is that even possible, to simulate a serial
> console over the parallel?

this doesn't sound very plausible, but you never know.

Re: [9fans] Anyone awake?

[David Presotto]

[-- Attachment #1: Type: text/plain, Size: 337 bytes --]

With much effort, probably.  Which side do you want to plug the parallel port
into?  If its the PC, you're going to have to do your own oversampling
of the incoming signal to build characters.  You might get away with doing
it in a user program if its priority is high enough but I'ld say you'll
probably end up writing a driver...

[-- Attachment #2: Type: message/rfc822, Size: 2752 bytes --]

From: northern snowfall <dbailey27@ameritech.net>
To: 9fans@cse.psu.edu
Subject: [9fans] Anyone awake?
Date: Sun, 27 Jul 2003 03:37:44 -0500
Message-ID: <3F238F58.7000202@ameritech.net>

Hey all,
	I went to a computer show tonight and found a
MiniDIN8 -> DB25 cable for a Macintosh. Since my partner-
in-crime is away mountain climbing, I have no idea how
to set this up.

	Google searches only reveal documentation on
setting up serial consoles on the server side, not the
client side. I'm planning on using an IBM PC (either plan9
or UNIX) as the terminal. Can anyone give me any pointers
on how to set this up?

	Since the cable is DB25, I'm lookin' at using my
parallel port. Is that even possible, to simulate a serial
console over the parallel? Or, am I looking at using another
adapter to connect the parallel to serial?

Thanks, as always,

Don

http://www.7f.no-ip.com/~north_

Re: [9fans] Anyone awake?

[John DeGood]

Your Mac RS-232 port has typical voltage swings from -12 to +12 volts.
Your PC parallel port is TTL logic with voltage swings from 0 to +5
volts.  To electrically connect the 2 together you'd need a TTL ->
RS-232 transceiver, otherwise you may smoke the PC's parallel port.
Even if it doesn't smoke, it probably won't work without a transceiver.
And then there's the matter of emulating a UART on the Plan 9 parallel
port side, but of course that's easy because it's only software. :-)

If you want to save yourself a lot of grief, construct or buy a DB25F to
DB9F null modem cable.

John

northern snowfall wrote:

> Hey all,
>     I went to a computer show tonight and found a
> MiniDIN8 -> DB25 cable for a Macintosh. Since my partner-
> in-crime is away mountain climbing, I have no idea how
> to set this up.
>
>     Google searches only reveal documentation on
> setting up serial consoles on the server side, not the
> client side. I'm planning on using an IBM PC (either plan9
> or UNIX) as the terminal. Can anyone give me any pointers
> on how to set this up?
>
>     Since the cable is DB25, I'm lookin' at using my
> parallel port. Is that even possible, to simulate a serial
> console over the parallel? Or, am I looking at using another
> adapter to connect the parallel to serial?
>
> Thanks, as always,
>
> Don
>
> http://www.7f.no-ip.com/~north_
>
>

Re: [9fans] Anyone awake?

[boyd, rounin]

> If you want to save yourself a lot of grief, construct or buy a DB25F to
> DB9F null modem cable.

that's what i woulda thought, but assumed there was a good reason why
it hadn't been done.

Re[2]: [9fans] Anyone awake?

[Martin Althoff]

As posted earlier the hardware for parallel ports and serial ports is
rather different. While it might be possible to hide that under a
software layer might be doable, the elec-tricks might cause a problem
when directly connecting them.

Remembering PC (not mac) stone age times vaguely, there were serial
ports (cards) that had DB25 connectors. Did the Mac ever use those?

The difference to the parallel connector was in gender, though that
was sometimes confused.

A DIN8/DB25 adapter cable would make sense in that context as I
believe mac's used DIN8 connectors quite early. I once owned a nifty
connector cable that came with an early version of PC Anywhere (or
something like that) which had each type of connector at either end to
connect 2 serial or (!) 2 parallel port.

 From the memory chest....
Martin

Re: Re[2]: [9fans] Anyone awake?

[jmk]

I'm a bit confused here. Is the DIN8 out of the Mac serial or
parallel signalling? If it's serial then all you need (as has been
pointed out), is a DB25 to DB9 converter, they cost practically
nothing and we have boxes of them. There was a time when PCs came
with one serial port DB9 and the other DB25.

If I remember correctly (and the chances of that get slimmer each
day) that is how we connected the NeXT up - there was a DIN8 to DB25
cable to which we attached either a DB25 to DB9 or a DB25 to RJ45
converter.

Re: Re[2]: [9fans] Anyone awake?

[Jack Johnson]

On Sun, 2003-07-27 at 09:43, jmk@plan9.bell-labs.com wrote:
> I'm a bit confused here. Is the DIN8 out of the Mac serial or
> parallel signalling? If it's serial then all you need (as has been
> pointed out), is a DB25 to DB9 converter, they cost practically
> nothing and we have boxes of them. There was a time when PCs came
> with one serial port DB9 and the other DB25.

It should be serial.

On ancient Macs, there was some minor hardware difference that would
only allow LocalTalk over the "Printer" port, but that difference
evaporated ages ago (though it wasn't an option to switch to the other
port until OpenTransport came along).

I just realized I know way more about that than I care to.

Anyway, in the pre-USB Mac days you'd find that if you wanted an
external modem, it would cost you another $20 over an external PC modem,
and the only difference was the enclosed software and the cable.  A PC
modem and a random DIN8->DB25 cable would do the trick just as well.

And, as mentioned before, similar scenarios with DB25 null-modem
adapters or dumb terminals that support it will work just fine doing Mac
<-> whatever serial data.  If you have a used computer store in town (or
work for an organization with a decent basement), you can usually find a
dumb terminal pretty cheap, and I find it's easier to just keep one in
the garage in case of emergency rather than deal with hunting down
cables, a spare machine for serial configuration/debugging, etc.

-Jack

Re[2]: [9fans] Anyone awake?

[Martin Althoff]

Hello northern snowfall
Hm, and if you came back toasted (or so..) you shouldn't mess with
gombudas...  8*>
cheerio,
Martin

Re[2]: [9fans] Anyone awake?

[Martin Althoff]

> But, I was so excited to try my newly obtained cable!!!
> Can you blame me? I sure cant.
Nah, I've clobbered so many systems in early morning sessions in
similar states. Sometimes its just necessary to take that risk....
Good fun and practice to fix it all again later. Few minutes ago I saw
sparks (!) flying when attempting to power on by short circuting the
pwr on connectors... The board's still alive ... phew :) And I'm still
hours away from a pint
Martin

Re: [9fans] Anyone awake?

[northern snowfall]

Yeah, uhhh...

    My friends took me out for a night of pubs, last night
for like the first time in a good 5 months.

    I returned properly toasted.

    Anyhoo, Skip quickly smacked me back into reality when
he realized that I'd confused RS232 DB25 with IBMPC DB25
parallel ports. Woo hoo! :-/

    Thank God I was too tired to try the parallel port
thing, or I would have ended up frying something, hahaha.

    *However*, because of the ensuing confusion I caused
with that post, I dont feel so damned bad about mucking
up. Haha at you all, too! ;-)

    I think the problem is I've got a laplink cable when
I just need a female -> female DB9 for the last segment
of the connection. Then again... that DB25->DB9 thing
may-or-may-not be a null modem.

    Bah, whatever, I'll go to Radio Shack later.

Thanks for the help, none the less, all. Skip sent me a
pretty cool website that "asserted" the "hey ya drunk
bastard what do you think you're doin" pin in my brain.

http://www.camiresearch.com/Data_Com_Basics/RS232_standard.html

Don

http://www.7f.no-ip.com/~north_

Re: [9fans] Anyone awake?

[northern snowfall]

>
>
>Hm, and if you came back toasted (or so..) you shouldn't mess with
>gombudas...
>
But, I was so excited to try my newly obtained cable!!!
Can you blame me? I sure cant.

Don

http://www.7f.no-ip.com/~north_

Re: [9fans] Anyone awake?

[ron minnich]

On Sun, 27 Jul 2003, boyd, rounin wrote:

> > Since the cable is DB25, I'm lookin' at using my
> > parallel port. Is that even possible, to simulate a serial
> > console over the parallel?
>
> this doesn't sound very plausible, but you never know.

it's doable but you don't want to do it.

Get yerself from radio whack the standard serial db25/db9. Figure out how
things are wired, and in general you're safing doing the usual:
swap 2&3
pass 7 through

Then you take your mac db9->db25 and your db25->db9 and you should be
good.

If modem controls seem like they're causing trouble let me know, there's a
standard list of pins you tie together.

ron

[9fans] Anyone awake?

[A. Baker]

He's right about the Mac modem cable.

Go here:

http://www.lowendmac.com/

they'll answer all (most) your questions.

Stuff:

http://www.blackbox.com/


=====
Boojum

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