14 Oct
2006
14 Oct
'06
10:14 p.m.
Well, this is my first post to the list in quite a while; most of you may
not even remember me... but I have been lurking.
Now I have a problem I need help with. I have a PDT-11/150HC, the dual drive
model with 32KW and the 3 extra serial ports. It had been working fine, up
through last year, when I stored it.
I was working on another project, building a PDP-11/53 from a DECServer 550
(like Jonathan Engdahl's) when I needed to copy some floppies. I brought out
the trusty old PDT, and of course, it wouldn't work.
I am using a VT420 with DECConnect wire and shells to talk to the PDT. The
VT and wires are all known good, tested with other equipment.
What happens is that when I turn the PDT on and type the 2 "@" characters to
set the baud rate (4800), the #2 led properly goes out, the RUN led comes
on, but NOTHING comes back to the terminal. Thinking that I needed a NULL
MODEM in the cable, I put a MMJ crossover connector block between the
terminal and the PDT. Strangely, I had exactly the same results - nothing
out on the monitor - with TX and RX swapped how the heck does this happen?
As I recall, the usual response is something like "Press B to Boot". In any
event, pressing "B" does nothing either.
I have performed the self test with the lid off and modules elevated and the
result was that the first 4 LED's on the Intelligence Module came on.
This is result #17, indicating that either the DISK Controller Module or
Cable G1 has failed and need to be replaced - impossible, at least in the
case of the Disk Module. Besides, what does this have to do with no response
on the terminal?
My next step is to test the power supply and trace power to the various
modules, as per the Mini-Maintenance manual. I'm hoping that someone on the
list is more familiar with the PDT and can offer useful suggestions that
might shorten an exhaustive troubleshooting effort - I'm not really up to
it.
I have as resources 3 books, 1) The PDT 11/150 User Guide (EK-PT150UG-001),
2) The PDT 11/150 Installation Guide (EK-PT150-IN-002), and 3) The PDT
11/150 Mini-Maintenance Hardware Guide (EK-PT150-J1-002). I would very much
like to get a copy of EK-PT150-TM, the Technical manual, in print or PDF
format.
I also have the usual DVM, a Tektronix 2215 dual channel scope, and the
memories of being an electronics technician (with a radiotelephone license)
during my late 20's, a lifetime ago. I spent the last 20 years of my
so-called career as a systems programmer and am now retired.
Can someone that knows about the PDT assist me? All useful input
appreciated!
Stuart Johnson
Ssj152 AT charter DOT net
Old man, Old hobby
16 Oct
16 Oct
2:20 a.m.
Stuart Johnson wrote:
Well, this is my first post to the list in quite a
while; most of you may
not even remember me... but I have been lurking.
Now I have a problem I need help with. I have a PDT-11/150HC, the dual drive
model with 32KW and the 3 extra serial ports. It had been working fine, up
through last year, when I stored it.
I was working on another project, building a PDP-11/53 from a DECServer 550
(like Jonathan Engdahl's) when I needed to copy some floppies. I brought out
the trusty old PDT, and of course, it wouldn't work.
I am using a VT420 with DECConnect wire and shells to talk to the PDT. The
VT and wires are all known good, tested with other equipment.
What happens is that when I turn the PDT on and type the 2 "@" characters to
set the baud rate (4800), the #2 led properly goes out, the RUN led comes
on, but NOTHING comes back to the terminal. Thinking that I needed a NULL
MODEM in the cable, I put a MMJ crossover connector block between the
terminal and the PDT. Strangely, I had exactly the same results - nothing
out on the monitor - with TX and RX swapped how the heck does this happen?
As I recall, the usual response is something like "Press B to Boot". In any
event, pressing "B" does nothing either.
To test weither you need a null-modem or not, when you
have a 25 pin conector, get one of those RS-232 line
monitors (available at RadioShack for < $10.00) which
display several of the signals using leds. If both pin 2 and
3 light up, you are probably Ok, If only one lights up,
you probably need a null modem. If you then put in a
null modem, and still only have one light, you have a
bad (cable, interface, etc).
I have performed the self test with the lid off and
modules elevated and the
result was that the first 4 LED's on the Intelligence Module came on.
This is result #17, indicating that either the DISK Controller Module or
Cable G1 has failed and need to be replaced - impossible, at least in the
case of the Disk Module. Besides, what does this have to do with no response
on the terminal?
12:41 p.m.
On Mon, 16 Oct 2006, Kevin Handy wrote:
To test weither you need a null-modem or not, when
you
have a 25 pin conector, get one of those RS-232 line
monitors (available at RadioShack for < $10.00) which
display several of the signals using leds. If both pin 2 and
3 light up, you are probably Ok, If only one lights up,
you probably need a null modem. If you then put in a
null modem, and still only have one light, you have a
bad (cable, interface, etc).
I was at a Radio Shack a couple months ago and observed these line
monitors being removed from inventory. They said they'd be liquidated by
someone else. Jameco may be a more reliable source for this gizmo now.
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
4:44 p.m.
On Monday 16 October 2006 12:41 pm, David Griffith wrote:
On Mon, 16 Oct 2006, Kevin Handy wrote:
I forget where I got mine, some mail-order outfit back when and I was
ordering some other stuff and got that while I was at it. A very handy
gadget to be sure. I also paid half the price that RS was asking for theirs,
which if I'm remembering right was $14.95 or so.
What I do with 'em is plug one side in alone, and note what lights up and
what doesn't, then do the other side alone. That'll give me a pretty good
indication of whether or not I need to cross any lines.
--
Member of the toughest, meanest, dealiest, most unrelenting -- and
ablest -- form of life in this section of spac, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
To test weither you need a null-modem or not,
when you
have a 25 pin conector, get one of those RS-232 line
monitors (available at RadioShack for < $10.00) which
display several of the signals using leds. If both pin 2 and
3 light up, you are probably Ok, If only one lights up,
you probably need a null modem. If you then put in a
null modem, and still only have one light, you have a
bad (cable, interface, etc).
I was at a Radio Shack a couple months ago and observed these line
monitors being removed from inventory. They said they'd be liquidated by
someone else. Jameco may be a more reliable source for this gizmo now. 
6:07 p.m.
To test weither you need a null-modem or not, when
you
have a 25 pin conector, get one of those RS-232 line
monitors (available at RadioShack for < $10.00) which
display several of the signals using leds. If both pin 2 and
3 light up, you are probably Ok, If only one lights up,
you probably need a null modem. If you then put in a
null modem, and still only have one light, you have a
bad (cable, interface, etc).
I was at a Radio Shack a couple months ago and observed these line
monitors being removed from inventory. They said they'd be liquidated by
someone else. Jameco may be a more reliable source for this gizmo now. 
6:30 p.m.
gadget to be
sure. I also paid half the price that RS was asking for theirs,
which if I'm remembering right was $14.95 or so.
Fry's has them in
bucketloads. I think mine was $10. Very handy. 
7:33 p.m.
Fred Cisin wrote:
Last time that I bought any of those from Radio Shack
or Fry's,
I had to pop it open and resolder most of the connections.
When they're selling stuff with worse soldering than MINE,
it's getting pretty bad.
Hey I got a board that needs soldering...
I just found out I need Reading glasses, I better get all
my stuff I wanted to build *now* while a got few decades left to
enjoy them. :)
Grumpy Ol' Fred cisin at xenosoft.com
17 Oct
17 Oct
1:05 p.m.
On 10/17/06, Fred Cisin <cisin at xenosoft.com> wrote:
Last time that I bought any of those from Radio Shack
or Fry's,
I had to pop it open and resolder most of the connections.
I did for mine, too, but that was 15 years ago. If you don't buy the
expensive ones from a company like Black Box, expect to have to fix
cheap workmanship.
OTOH, my $10 unit was in tiptop shape after 5 minutes work, so
overall, it still was a good price.
-ethan
6:27 p.m.
On Wed, 18 Oct 2006, Ethan Dicks wrote:
On 10/17/06, Fred Cisin <cisin at xenosoft.com>
wrote:
Oddly enough, I've not had any problems with mine, though having said
that, I'll probably have to open it up next time I go to use it.
I've never completely understood Black Box's business model. Some of the
adapters and cables they sell at a premium price are simply OEM'd products
with their own sticker/logo stuck on them. Did they offer some sort of
guarantee beyond what the manufacturer would have offered?
Last time that I bought any of those from Radio
Shack or Fry's, I had
to pop it open and resolder most of the connections.
I did for mine, too, but that was 15 years ago. If you don't buy the
expensive ones from a company like Black Box, expect to have to fix
cheap workmanship. OTOH, my $10 unit was in tiptop shape after 5 minutes
work, so overall,
it still was a good price.
I actually picked up an older but practically new serial analyzer on eBay
this last month for about $10. Its a Datacom Technologies DataTool 5500,
which is both an analyzer and a breakout box built into one unit. (Datacom
Technologies either became Tempo or got bought up by them, I can't
remember now.) I believe it only works up to 38400 baud or so, but it will
work great for most stuff that I work with. Wish I'd had it back in the
mid 90s though ;)
-Toth
16 Oct
16 Oct
6:04 p.m.
On Oct 16, 2006, at 12:41 PM, David Griffith wrote:
That sucks. They are extremely handy little devices. I use mine
all the time.
-Dave
--
Dave McGuire
Cape Coral, FL
To test
weither you need a null-modem or not, when you
have a 25 pin conector, get one of those RS-232 line
monitors (available at RadioShack for < $10.00) which
display several of the signals using leds. If both pin 2 and
3 light up, you are probably Ok, If only one lights up,
you probably need a null modem. If you then put in a
null modem, and still only have one light, you have a
bad (cable, interface, etc).
I was at a Radio Shack a couple months ago and observed these line
monitors being removed from inventory. They said they'd be
liquidated by
someone else. Jameco may be a more reliable source for this gizmo
now. 
7:03 p.m.
I was at a
Radio Shack a couple months ago and observed these line
monitors being removed from inventory. They said they'd be
liquidated by
someone else. Jameco may be a more reliable source for this gizmo
now.
That sucks. They are extremely handy little devices. I use mine
all the time. 
7:15 p.m.
On Oct 16, 2006, at 12:41 PM, David Griffith wrote:
I was at a Radio Shack a couple months ago and
observed these line
monitors being removed from inventory. They said they'd be
liquidated by someone else. Jameco may be a more reliable source for
this gizmo
now.
I bought mine sometime back in the early 80's/late 70's along with a bunch
of the DB-25 "jumper boxes". A straight-through DB-25 cable, a couple of
gender-changers, a couple of DA-9-to-DB-25 converters, a null modem jumper
box and a LED monitor box pretty much will get you through any RS232C
hookup problem.
I guess this all means that RS232C has fallen into the category of
"obsolescent technology". Well, it had a good long run--and it's a heckuva
lot easier to deal with than USB...
Cheers,
Chuck
17 Oct
17 Oct
12:04 p.m.
On Oct 16, 2006, at 7:15 PM, Chuck Guzis wrote:
I guess this all means that RS232C has fallen into the
category of
"obsolescent technology".
Ha! Not anytime soon, for better or worse. The same thing was
said about things like the Z80, which is being made in larger
quantities than ever before.
-Dave
12:28 p.m.
On 10/17/2006 at 12:04 PM Dave McGuire wrote:
Ha! Not anytime soon, for better or worse. The
same thing was
said about things like the Z80, which is being made in larger
quantities than ever before.
Observe that I said that RS-232C was "obsolescent" and not
"obsolete"--I'm
merely implying that it's on a slow decline. The primary uses--connecting
an external modem or terminal to a PC aren't nearly as important today as
they once were. USB and other interfaces have largely usurped the position
that the old "serial port" interface enjoyed. There will be a time when
the standard PeeCee lacks a RS232C port--unless added by the user with a
USB adapter--just like the way the situation with the floppy drive is
evolving.
I've heard floppy drives on laptops described in magazine reviews as
"quaint" in much the same way that an acetylene headlamp on a modern car
might be.
Cheers,
Chuck
1:39 p.m.
Chuck Guzis wrote:
Indeed, I stand corrected, and I agree with your assessment. The
applications of RS232 certainly have changed over the years.
Ha! Not
anytime soon, for better or worse. The same thing was
said about things like the Z80, which is being made in larger
quantities than ever before.
Observe that I said that RS-232C was "obsolescent" and not
"obsolete"--I'm
merely implying that it's on a slow decline. The primary uses--connecting
an external modem or terminal to a PC aren't nearly as important today as
they once were. USB and other interfaces have largely usurped the position
that the old "serial port" interface enjoyed. There will be a time when
the standard PeeCee lacks a RS232C port--unless added by the user with a
USB adapter--just like the way the situation with the floppy drive is
evolving.
Indeed, I think that time has already come, has it not?
-Dave
--
Dave McGuire
Cape Coral, FL
2:05 p.m.
On Tuesday 17 October 2006 13:39, Dave McGuire wrote:
Chuck Guzis wrote:
Indeed, I stand corrected, and I agree with your assessment. The
applications of RS232 certainly have changed over the years.
I dunno. Almost all the machines we have at work, which I admin, have
RS-232 console ports.... we even set up our crappy Dell 1U servers with
a serial console connection. That's one use for a serial port (and the
most common that I can think of now-a-days) that's been around for well
over 30 years...
And, by the way, it's so much easier to use a text-based serial console
over a remote connection from home to fix a problem with a machine,
than to either do KVM over IP or VNC-based system management. A lot
(if not most) of the machines that we care about enough to have
consoles, even PC's, allow access to the firmware/BIOS from the serial
console, as well as our bootloader and OS supporting a serial
console. :)
Pat
--
Purdue University Research Computing --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
Ha!
Not anytime soon, for better or worse. The same thing was
said about things like the Z80, which is being made in larger
quantities than ever before.
Observe that I said that RS-232C was "obsolescent" and not
"obsolete"--I'm merely implying that it's on a slow decline. The
primary uses--connecting an external modem or terminal to a PC
aren't nearly as important today as they once were. USB and other
interfaces have largely usurped the position that the old "serial
port" interface enjoyed. 
2:12 p.m.
Pat wrote....
Almost all the machines we have at work, which I
admin, have
RS-232 console ports....
That's true, most of your name brand data-center class
Intel based (and
others) have full bios support for serial console. However, those are not
the typical machines a consumer buys.
Just try finding a laptop these days that has a serial port. You won't find
much (if any). I daresay more than half the consumer grade PC's for the home
do not have serial ports on them either nowdays.
RS232 as far as a general purpose consumer interface is dead.
Jay
2:26 p.m.
RS232 as far as a general purpose consumer interface is
dead.
Interestingly when I needed to configure a *10Gbps* interface today on
An HP 3500yl-48G switch, I needed to connect via RS232 (and VT100
emulation
Mode!!) to assign an IP address to the switch.
I'll grant that consumers are not buying 10G-capable switches today, but
it's interesting that such a new switch still expects you to initially
say
"hello" with an RS232 interface. (OK, the default is DHCP, but the point
still stands).
My RS232 breakout boxes are still a way from being retired.
Antonio
2:32 p.m.
I had written....
>RS232 as far as a general purpose consumer
interface is dead.
To which antonio replied...
Interestingly when I needed to configure a *10Gbps*
interface today on
An HP 3500yl-48G switch, I needed to connect via RS232 (and VT100
Uh... I DID say
general purpose CONSUMER grade. An HP 3500yl switch isn't
what I'd call consumer grade.
My RS232 breakout boxes are still a way from being
retired.
Oh, mine either. One of my specialties was RS232 in my "previous"
career. I
still have my breakout boxes, bert testers, serial protocol analyzers, etc.
They won't be going anywhere soon. But what I was saying is that from the
mom & pop at home buying a home computer or a home wireless router... rs232
IS dead.
Jay
2:32 p.m.
I'll grant that consumers are not buying
10G-capable switches today,
but it's interesting that such a new switch still expects you to
initially say "hello" with an RS232 interface. (OK, the default is
DHCP, but the point still stands).
I recently had occasion to configure a new low-end SMC switch (24
10/100 ports, four SFP 1000-capable ports; the 10/100 may actually be
10/100/1000).
It didn't even *have* a serial port. Which was very annoying, too,
especially since the manual did not include a description of how to
reset it to factory settings. (Fortunately, it still had the defaults,
and its Web(!) configuration interface had a help page which did
describe that mechanism.)
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
4:42 p.m.
On Oct 17, 2006, at 2:26 PM, <arcarlini at iee.org> wrote:
This is hardly "general-purpose consumer" hardware.
RS232 as far
as a general purpose consumer interface is dead.
Interestingly when I needed to configure a *10Gbps* interface today on
An HP 3500yl-48G switch, I needed to connect via RS232 (and VT100
emulation
Mode!!) to assign an IP address to the switch. I'll grant that consumers are not buying
10G-capable switches
today, but
it's interesting that such a new switch still expects you to initially
say
"hello" with an RS232 interface. (OK, the default is DHCP, but the
point
still stands).
My RS232 breakout boxes are still a way from being retired.
...as are everyone else's. As I just mentioned in another
message, I believe the "dead" comment was meant in relation to
desktop personal computing hardware. Indeed, I bought a PowerMac G4
shortly after their release, and it had no serial ports...that was at
least six years ago.
He did specifically state "as a general purpose consumer interface".
-Dave
--
Dave McGuire
Cape Coral, FL
10:39 p.m.
...as are everyone else's. As I just mentioned
in another
message, I believe the "dead" comment was meant in relation to
desktop personal computing hardware. Indeed, I bought a PowerMac G4
shortly after their release, and it had no serial ports...that was at
least six years ago.
The Blue & White G3 was the first Mac without any sort of serial port. The
beige ones do have them.
--
--------------------------------- personal: http://www.armory.com/~spectre/ ---
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com
-- BOND THEME NOW PLAYING: "On Her Majesty's Secret Service"
------------------
3:19 p.m.
Jay West wrote:
Pat wrote....
There are widgets available for PowerMacs and PowerBooks that
replaces the modem with either an RS232 or Classic Mac-style RS422 8-din
serial port. I couldn't quickly find the PB part, but here's one of the
RS422 doohickeys:
http://www.ramelectronics.net/html/ADA-GEE3.htm
System manufacturers would probably like to ditch RS232 and RS422,
and many have already, but the users won't let it die.
Doc
Almost all the machines we have at work, which I
admin, have
RS-232 console ports....
That's true, most of your name brand data-center class Intel based (and
others) have full bios support for serial console. However, those are
not the typical machines a consumer buys.
Just try finding a laptop these days that has a serial port. You won't
find much (if any). I daresay more than half the consumer grade PC's for
the home do not have serial ports on them either nowdays.
RS232 as far as a general purpose consumer interface is dead.
4:44 p.m.
On Oct 17, 2006, at 3:19 PM, Doc Shipley wrote:
System manufacturers would probably like to ditch
RS232 and
RS422, and many have already, but the users won't let it die.
Ahh, one of the few remaining instances in which the customer base
dictates what the vendors sell, instead of the vendors ramming
unwanted stuff down their customers' throats.
-Dave
--
Dave McGuire
Cape Coral, FL
18 Oct
18 Oct
4:46 a.m.
> RS232 as far as a general purpose consumer
interface is dead.
Tell that to my new Sony receiver STR DA3000es, full functional control
and status available over the rs232 on the back. Thats pretty much the
story for all the top end gear designed for integration with a multiroom
etc. type system.
17 Oct
17 Oct
4:35 p.m.
Jay West wrote:
Pat wrote....
> Almost all the machines we have at work, which I admin, have
> RS-232 console ports....
Just try finding a laptop these days that has a serial
port. You won't
find much (if any). I daresay more than half the consumer grade PC's for
the home do not have serial ports on them either nowdays.
None of the recent desktops I've seen have one, but some of the most
recent Toshiba laptops do, interestingly. I almost bought one for that
very reason.
RS232 as far as a general purpose consumer interface
is dead.
True. Fortunately, the USB-to-RS232 adapters I've seen recently work
well, unlike some I saw a year or two ago.
--
Pete Peter Turnbull
Network Manager
University of York
5:09 p.m.
We have a Dell box at work that doesn't even have a Centronics parallel port
-- just USB ports. I needed to get a USB-to-Parallel converter cable to hook
up the laserjet to this box.
Bob
From: "Jay West" <jwest at
classiccmp.org>
Reply-To: "General Discussion: On-Topic and Off-Topic
Posts"<cctalk at classiccmp.org>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: Re: PDT-11/150 down
Date: Tue, 17 Oct 2006 13:12:54 -0500
Pat wrote....
Almost all the machines we have at work, which I
admin, have
RS-232 console ports....
That's true, most of your name brand data-center class
Intel based (and
others) have full bios support for serial console. However, those are not
the typical machines a consumer buys.
Just try finding a laptop these days that has a serial port. You won't find
much (if any). I daresay more than half the consumer grade PC's for the
home do not have serial ports on them either nowdays.
RS232 as far as a general purpose consumer interface is dead.
Jay
5:13 p.m.
Robert Feldman wrote:
We have a Dell box at work that doesn't even have
a Centronics parallel
port -- just USB ports. I needed to get a USB-to-Parallel converter
cable to hook up the laserjet to this box.
My new PC doesn't have one either, but that's no big loss as all of my
printers are on the network in one way or another.
Peace... Sridhar
6:17 p.m.
Jay West wrote:
Pat wrote....
I wonder why the original IBM PC didn't include it? I mean, typical machines
of that era relied on a serial terminal for control - yet IBM made it pretty
much compulsory to have a video board of some description (even if it was just
MDA). Sure, they probably never foresaw the PC as a server class system, but
given what everyone else was doing at the time I'm surprised they ruled the
feature out (at least without a BIOS rewrite).
OK, so you can redirect stuff under DOS (or another OS) once booted, but that
still means that on typical PC machines you get no feedback on the boot
process until the OS has control...
Almost all the machines we have at work, which I
admin, have
RS-232 console ports....
That's true, most of your name brand data-center
class Intel based (and
others) have full bios support for serial console. However, those are
not the typical machines a consumer buys. Just try finding a laptop these days that has a serial
port. You won't
find much (if any). I daresay more than half the consumer grade PC's for
the home do not have serial ports on them either nowdays.
That's why I still have this old Thinkpad - at least it has serial and
parallel built in (and USB for when I have to use it), even if it is a bit
long in the tooth.
[I'm struggling to avoid a general rant about USB at this point]
RS232 as far as a general purpose consumer interface
is dead.
In a way, I suppose it doesn't fit for a lot of devices beyond things like
terminals and modems and simple, low-speed stuff like UPS status/control. Most
consumer devices are just too bandwidth-hungry for serial - but that's what
parallel ports and SCSI were for; we didn't *need* yet another interface
standard...
Makes me wonder how well SCSI would have fared had it been hot-pluggable from
the start, as that seems to be the main benefit of USB (even if the Microsoft
guys can't seem to get the software side of it right!)
cheers
Jules
--
Put your viking helmet on
Spread that mayonnaise on the lawn
Don't you know it's Weasel Stomping Day
5:53 p.m.
On 10/17/2006 at 10:17 PM Jules Richardson wrote:
OK, so you can redirect stuff under DOS (or another OS)
once booted, but
that still means that on typical PC machines you get no feedback on the
boot
process until the OS has control...
Of course, even the original 5150 had a serial port--most people just tend
not to think of it as such. Namely, the keyboard interface. When the AT
came along, it was fully bidirectional.
Makes me wonder how well SCSI would have fared had it
been hot-pluggable
from the start, as that seems to be the main benefit of USB (even if the
Microsoft guys can't seem to get the software side of it right!)
You're forgetting how much voodoo factor there was to SCSI.
Cheers,
Chuck
18 Oct
18 Oct
1:42 p.m.
On Tuesday 17 October 2006 05:53 pm, Chuck Guzis wrote:
I've never personally found SCSI to be all that hard to deal with.
--
Member of the toughest, meanest, dealiest, most unrelenting -- and
ablest -- form of life in this section of spac, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
On 10/17/2006 at 10:17 PM Jules Richardson wrote:
Interesting thought. I have some XT-class hardware around still, but it's
been so long since I've messed with any of that I can't remember -- do you
_have to_ have video or other cards in there to get past POST?
OK, so you can redirect stuff under DOS (or
another OS) once booted, but
that still means that on typical PC machines you get no feedback on the
boot process until the OS has control...
Of course, even the original 5150 had a serial port--most people just tend
not to think of it as such. Namely, the keyboard interface. When the AT
came along, it was fully bidirectional. Makes me wonder
how well SCSI would have fared had it been hot-pluggable
from the start, as that seems to be the main benefit of USB (even if the
Microsoft guys can't seem to get the software side of it right!)
You're forgetting how much voodoo factor there was to SCSI.
3:54 p.m.
Roy J. Tellason wrote:
I'm pretty sure that it's been a fundamental PC feature from day 1,
annoyingly. Presumably IBM took the view that serial consoles were for minis
and mainframes, and that a PC was a desktop with a screen and so should always
have a video board (even if it was text-only)
[wonder what the first application that treated a PC as a server was? Quite
possibly some form of BBS software, but it'd be interesting to know]
I've never personally found SCSI to be all that hard to deal with.
Nor me. The trick for me was always to buy good-quality cables and
terminators, and to adhere to maximum cable lengths. I've had far more trouble
getting pairs of IDE devices playing well together than I've ever had getting
SCSI stuff working.
cheers
J.
--
If you've ever wondered how you get triangles from a cow
You need buttermilk and cheese, and an equilateral chainsaw
Of course,
even the original 5150 had a serial port--most people just tend
not to think of it as such. Namely, the keyboard interface. When the AT
came along, it was fully bidirectional.
Interesting thought. I have some XT-class hardware around still, but it's
been so long since I've messed with any of that I can't remember -- do you
_have to_ have video or other cards in there to get past POST? Makes me wonder how well SCSI would have fared had it
been hot-pluggable
from the start, as that seems to be the main benefit of USB (even if the
Microsoft guys can't seem to get the software side of it right!)
You're
forgetting how much voodoo factor there was to SCSI.
4:59 p.m.
On 10/18/2006 at 2:54 PM Jules Richardson wrote:
My perception is perhaps colored by my involvement with the field and, in
particular, SCSI tape drives. It never failed that we'd get at least one
support call a week saying something like "I got tape drive A, SCSI adapter
B and system C and it doesn't work." Where A B and C changed very
frequently. In particular, early SCSI was colored with devices that
*almost* behaved like the spec, but did something a bit peculiar, leading
to grief.
Cheers,
Chuck
I've never
personally found SCSI to be all that hard to deal with.
Nor me. The trick for me was always to buy good-quality cables and
terminators, and to adhere to maximum cable lengths. I've had far more
trouble
getting pairs of IDE devices playing well together than I've ever had
getting SCSI stuff working.
5:28 p.m.
Jules Richardson wrote:
Roy J. Tellason wrote:
trouble
I've never personally found SCSI to be all
that hard to deal with.
Nor me. The trick for me was always to buy good-quality cables and
terminators, and to adhere to maximum cable lengths. I've had far more getting pairs of IDE devices playing well together than
I've ever had
getting
SCSI stuff working.
The early problems (with SCSI-1) were down to differing interpretations
of the spec (what was mandatory, what was not etc.) Plus the usual
amount of works-OK-until-stressed stuff.
If you were just doing PC stuff and were using disks expected to be
sold into that environment you were probably OK. A slow ISA bus and
a largely single-tasking environment (under DOS) would have prevented
you seeing the various issues that drives had when hit hard.
Trying anything other than a disk (a tape, for example) on anything
other than the platform for which it was intended was "fun".
Antonio
8:07 p.m.
Of course, even the original 5150 had a serial port--most people just tend
not to think of it as such. Namely, the keyboard interface. When the AT
came along, it was fully bidirectional.
Interesting thought. I have some XT-class hardware around still, but it's 
17 Oct
17 Oct
7:55 p.m.
New subject: Hot swappable SCSI (was Re: PDT-11/150 down)
It was thus said that the Great Jules Richardson once stated:
Makes me wonder how well SCSI would have fared had it been hot-pluggable
from the start, as that seems to be the main benefit of USB (even if the
Microsoft guys can't seem to get the software side of it right!)
Would have been nice, and would have saved me 16 hours of recovery time
and my boss endless ribbing for attempting to add a SCSI drive to the AIX
system (the core of the ISP I was working for at the time) without shutting
it down first.
-spc (Not sure which version AIX, but it was late 93 when it happened)
18 Oct
18 Oct
1:34 p.m.
On Tuesday 17 October 2006 06:17 pm, Jules Richardson wrote:
Unless you were the mfr. and wanted a way cheaper interface connector maybe?
RS232 as far
as a general purpose consumer interface is dead.
In a way, I suppose it doesn't fit for a lot of devices beyond things like
terminals and modems and simple, low-speed stuff like UPS status/control.
Most consumer devices are just too bandwidth-hungry for serial - but that's
what parallel ports and SCSI were for; we didn't *need* yet another
interface standard... Makes me wonder how well SCSI would have fared had it
been hot-pluggable
from the start, as that seems to be the main benefit of USB (even if the
Microsoft guys can't seem to get the software side of it right!)
I've noticed that, where software that seems to want to deal with SCSI stuff
(in my case a flatbed scanner hooked to one machine and a burner hooked to
another) seems to want those devices hooked up and powered when they boot,
though I can do things like `cdrecord -scanbus` and get the software to
notice what's out there.
--
Member of the toughest, meanest, dealiest, most unrelenting -- and
ablest -- form of life in this section of spac, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
3:15 p.m.
Yeah, basically that's what firewire is all about. Serial SCSI pretty
much. With a much cheaper connector too. :-) And no more SCSI ID's or
terminators to fumble with.
Roy J. Tellason wrote:
Unless you were the mfr. and wanted a way cheaper
interface connector maybe?
Makes me wonder how well SCSI would have fared
had it been hot-pluggable
from the start, as that seems to be the main benefit of USB (even if the
Microsoft guys can't seem to get the software side of it right!)
I've noticed that, where software that seems to want to deal with SCSI stuff
(in my case a flatbed scanner hooked to one machine and a burner hooked to
another) seems to want those devices hooked up and powered when they boot,
though I can do things like `cdrecord -scanbus` and get the software to
notice what's out there.
17 Oct
17 Oct
4:39 p.m.
On Oct 17, 2006, at 2:05 PM, Patrick Finnegan wrote:
Indeed, I stand corrected, and I agree with your assessment. The
applications of RS232 certainly have changed over the years.
I dunno. Almost all the machines we have at work, which I admin, have
RS-232 console ports....
Well, all server-class computers have serial console ports. I
thought he was talking about PCs.
Ha! Not
anytime soon, for better or worse. The same thing was
said about things like the Z80, which is being made in larger
quantities than ever before.
Observe that I said that RS-232C was "obsolescent" and not
"obsolete"--I'm merely implying that it's on a slow decline. The
primary uses--connecting an external modem or terminal to a PC
aren't nearly as important today as they once were. USB and other
interfaces have largely usurped the position that the old "serial
port" interface enjoyed. we even set up our crappy Dell 1U servers with
a serial console connection. That's one use for a serial port (and
the
most common that I can think of now-a-days) that's been around for
well
over 30 years...
And, by the way, it's so much easier to use a text-based serial
console
over a remote connection from home to fix a problem with a machine,
than to either do KVM over IP or VNC-based system management. A lot
(if not most) of the machines that we care about enough to have
consoles, even PC's, allow access to the firmware/BIOS from the serial
console, as well as our bootloader and OS supporting a serial
console. :)
Oh absolutely. If you're serious about your data center, your
machines have serial consoles...it's as simple as that.
-Dave
--
Dave McGuire
Cape Coral, FL
2:27 p.m.
Dave McGuire wrote:
Not that I know of. The dual-core Opteron nForce 550 system I just
built has one. (But only one.)
Peace... Sridhar
There will be
a time when
the standard PeeCee lacks a RS232C port--unless added by the user with a
USB adapter--just like the way the situation with the floppy drive is
evolving.
Indeed, I think that time has already come, has it not?
2:49 p.m.
Jay West wrote:
Sridhar wrote....
I don't know if I could have bought a machine like this one at Best Buy,
but I am reasonably certain that I could have bought all of the parts I
used there. In fact, I did indeed buy my case, power supply, DVD burner
and video card at Best Buy. This is a sub-$500 gaming box.
Peace... Sridhar
Not that I know of. The dual-core Opteron nForce
550 system I just
built has one. (But only one.)
I wouldn't qualify a dual core opteron as typical stuff that shows up a
a flea market, or at best buy.
1:38 p.m.
On Oct 16, 2006, at 12:41 PM, David Griffith wrote:
A few things I'll add to that list :
A 'universal RS232 ribbon cable'. I've never seen these for sale, you
have to make them. It's a length of 25 way IDC cable with a DB25 plug and
a DB25 socket crimped on at each end (4 conenctors total). It gets round
gender problems, and it's also useful for linking my Tekky datacoms
analyser to a line (this has a single DB25 socket on the back)
I made up 2 different null-modem adapters. The fist one is labelled 'full
handshake' and has the following connections :
1 (PG)---------------1 (PG)
2 (TxD) ------------ 3 (RxD)
3 (RxD) -------------2 (TxD)
4 (RTS)--------------5 (CTS)
5 (CTS) -------------4 (RTS)
6 (DSR)---+----------20 (DTR)
8 (DCD)---+
7 (SG)---------------7 (SG)
20 (DTR) --------+---6 (DSR)
+---8 (DCD)
The other is labelled 'loopback handshake) and has these connections
1 (PG)---------------1 (PG)
2 (TxD)--------------3 (RxD)
3 (RxD)--------------2 (TxD)
4 (RTS)---+ +---4 (RTS)
5 (CTS----+ +---5 (CTS)
7 (SG)---------------7 (SG)
6 (DSR)---+ +---6 (DSR)
8 (DCD)---+ +---8 (DCD)
20 (DTR)--+ +---20 (DTR)
The first is used when both ends make sensible use of the handshake
lines, the second when the don't ( and you rely on software handshaking).
I had to make up both of these myself, the null-modem adapter I bought
ready made had a _crazy_ set of internal connections (I think 4 and 5 at
each side were linked and linked to 4 and 5 at the other end). And for
some reason the purchased one had a plug on one end and a socket on the
other (mine home-made ones are sockets at both ends).
-tony
I was at a Radio Shack a couple months ago and
observed these line
monitors being removed from inventory. They said they'd be
liquidated by someone else. Jameco may be a more reliable source for
this gizmo
now.
I bought mine sometime back in the early 80's/late 70's along with a bunch
of the DB-25 "jumper boxes". A straight-through DB-25 cable, a couple of
gender-changers, a couple of DA-9-to-DB-25 converters, a null modem jumper
box and a LED monitor box pretty much will get you through any RS232C
hookup problem. 
4:18 p.m.
In article <m1GZstK-000IxxC at p850ug1>,
ard at p850ug1.demon.co.uk (Tony Duell) writes:
A 'universal RS232 ribbon cable'. I've
never seen these for sale, you
have to make them. [...]
I've seen these for sale. I've even seen them with the DB9 style and
DB25 style connectors on each end.
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://www.xmission.com/~legalize/book/download/index.html>
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