Should I grab the iron and change pin 1 to 7?
I suggest you find out what's wrong and fix it the way it's supposed
to be..
Depending on config of the system chasseie ground and signal ground
might be isolated.
If there is a "klinik" (another DB25 port, or if it has DB25's for
user terminals (check if there is a board connected on the able)
measure from pin 7 to pin 7 in another connector.
My guess is that someone has "fried" the console ground wire with
current, and you should be lucky more stuff is not dead. -:)
-_P
On 2015-02-12 19:23, Cory Smelosky wrote:
None of the pins on the connector are ground. That'd explain some things.
I just want to check here, how you asserted that? The signal ground is not the same as chassis ground, so I hope you didn't just measure against some random point on a chassis, or some random pin on a DB25...
Johnny
Sent from my iPhone
On Feb 12, 2015, at 13:22, Peter Lothberg <roll at Stupi.SE> wrote:
Straight gives me gibberish, null gives me output. I'll find my straight.
FWIW, if the SC40 is wired like a "real" DEC computer, then a null modem
cable would be required between the console DB25 and a VTxxx.
If the wiring (ground) was even close to correct, either crossed or non
crossed should give NO characters. -:)
--P
Okay!
Should I grab the iron and change pin 1 to 7?
Signal ground is currently floating
Sent from my iPhone
On Feb 12, 2015, at 13:59, Peter Lothberg <roll at Stupi.SE> wrote:
Cory,
When you have sorted out the console thing, do:
NSP>show cpu assIGNMENT
CPU0 has the following channels assigned:
No IU channels
RH channels:
LOGICAL ACTUAL TYPE MISCELLANEOUS
5 CHN1 EI
0 CHN0 SI MASK=0x03
1 CHN2 SI MASK=0x03
7 CHN3 CI PORT#=0x3
DTEs:
LOGICAL ACTUAL TYPE MISCELLANEOUS
0 FE PRIVILEGED
and
NSP>dir
-P
Cory,
When you have sorted out the console thing, do:
NSP>show cpu assIGNMENT
CPU0 has the following channels assigned:
No IU channels
RH channels:
LOGICAL ACTUAL TYPE MISCELLANEOUS
5 CHN1 EI
0 CHN0 SI MASK=0x03
1 CHN2 SI MASK=0x03
7 CHN3 CI PORT#=0x3
DTEs:
LOGICAL ACTUAL TYPE MISCELLANEOUS
0 FE PRIVILEGED
and
NSP>dir
-P
Twisted cable...sorry. Pin far left with cable mated, looking at the mate is ground.
Sent from my iPhone
On Feb 12, 2015, at 13:23, Cory Smelosky <b4 at gewt.net> wrote:
None of the pins on the connector are ground. That'd explain some things.
Sent from my iPhone
On Feb 12, 2015, at 13:22, Peter Lothberg <roll at Stupi.SE> wrote:
Straight gives me gibberish, null gives me output. I'll find my straight.
FWIW, if the SC40 is wired like a "real" DEC computer, then a null modem
cable would be required between the console DB25 and a VTxxx.
If the wiring (ground) was even close to correct, either crossed or non
crossed should give NO characters. -:)
--P
Straight gives me gibberish, null gives me output. I'll find my straight.
FWIW, if the SC40 is wired like a "real" DEC computer, then a null modem
cable would be required between the console DB25 and a VTxxx.
If the wiring (ground) was even close to correct, either crossed or non
crossed should give NO characters. -:)
None of the pins on the connector are ground. That'd explain some things.
Two options:
- A cable is loose/bad
- In it's previus life someone had a ground loop, eg, like if
you plug the SC40 in to a non-grounded plug and the terminal is
grounded.
Suggest you solve this problem, trace pin 7 back to the sparc board.
---P
None of the pins on the connector are ground. That'd explain some things.
Sent from my iPhone
On Feb 12, 2015, at 13:22, Peter Lothberg <roll at Stupi.SE> wrote:
Straight gives me gibberish, null gives me output. I'll find my straight.
FWIW, if the SC40 is wired like a "real" DEC computer, then a null modem
cable would be required between the console DB25 and a VTxxx.
If the wiring (ground) was even close to correct, either crossed or non
crossed should give NO characters. -:)
--P
Straight gives me gibberish, null gives me output. I'll find my straight.
FWIW, if the SC40 is wired like a "real" DEC computer, then a null modem
cable would be required between the console DB25 and a VTxxx.
If the wiring (ground) was even close to correct, either crossed or non
crossed should give NO characters. -:)
--P
On Feb 12, 2015 12:44 PM, "Cory Smelosky" <b4 at gewt.net> wrote: > On Feb 12, 2015, at 12:42, Peter Lothberg <roll at Stupi.SE> wrote: > > >> What kind of console terminal plug is on the SC40? > > > > SC30 a DB25 hanging in twisted pair wire_wrap cables..... > > SC40 a DB25 on the panel, wired perfetly normal, a stright > > male-female cable would plug a vt100 right in. > > Straight gives me gibberish, null gives me output. I'll find my straight. >
You've got cabling issues. Using a straight cable when you actually need a "null modem" cable should result in nothing, not gibberish.
I'm betting Bob Armstrong is correct.
Jim
Straight gives me gibberish, null gives me output. I'll find my straight.
FWIW, if the SC40 is wired like a "real" DEC computer, then a null modem
cable would be required between the console DB25 and a VTxxx.
Bob
