[net.micro.att] Unix PC Noise

dempsey@sdcrdcf.UUCP (John Dempsey) (05/13/86)

When my Unix PC makes noise from the hard disk, you can lift the bottom, 
left-side of the screen and the noise will either stop or at least be 
reduced.  It seems that the weight of the screen applies pressure on top 
of the hard disk.  Unless others have a different reason, I, for one who 
is bothered by the amount of noise the Unix PC generates, am not thrilled
by AT&T's ``lack of support'' for their terminal screen on top of the
rest of the system.  What is one supposed to do?  Be a one-arm programmer?
(<-:).

P.S.  Does anyone know why the Unix PC wasn't built with its screen separated 
from the CPU and hard disk.  Some may say for bit-mapped graphics or higher 
speed, but look at the NGEN made by Convergent Technologies (the makers of 
the Unix PC).  The NGEN separates its bit-mapped screen, keyboard, CPU, hard 
disk, and power supply into separate components that connect together.
Hardware wise, I think it is designed better than the Unix PC.
-- 
-------------------------------------------------------------------------------
						 John Dempsey
						 System Development Corporation
						 A Burroughs Company
Disclaimer: Everything!			  	 sdcrdcf!dempsey
-------------------------------------------------------------------------------

sheldon@quest.UUCP (Scott sheldon Bertilson) (05/19/86)

> When my Unix PC makes noise from the hard disk, you can lift the bottom, 
> left-side of the screen and the noise will either stop or at least be 
> reduced.

  I had similar problems with a UNIX pc I work with.  It turns out
(after opening the machine up and calling MiniScribe) that there
is a contact bushing on the bottom of the drive that is being pressed
too tightly.  You can pull the drive and bend the spring finger so it
doesn't press so tightly.  It is there for electrical contact so it
doesn't have to be very tight.
-- 

Scott S. Bertilson   ...ihnp4!quest!sheldon

dave@safari.UUCP (dave munroe) (05/26/86)

> > When my Unix PC makes noise from the hard disk, you can lift the bottom, 
> > left-side of the screen and the noise will either stop or at least be 
> > reduced.
> 
>   I had similar problems with a UNIX pc I work with.  It turns out
> (after opening the machine up and calling MiniScribe) that there
> is a contact bushing on the bottom of the drive that is being pressed
> too tightly...

The 20MB drive on my Unix PC is also quite loud.  Does anyone know if this
is also the case with the larger capacity disks offered for the Unix PC?

Since I am new to the net, I do not know what Unix PC topics have been
covered to date.  If anyone is keeping a collection, I would appreciate
getting a copy by mail (if no one is keeping a collection, I will try to
take up the task).  I've been running my system continuously for about 8
months and am extremely pleased with the quality and speed of the machine.

Below are some observations and questions:

1.	The version 2.0 diagnostic disk did not give the option for parking the
	disk heads, so systems that my have been moved around a bit may have
	more than the usual number of bad blocks (my version 3.0 diagnostic
	disk reported 32 bad blocks and took an hour to format the disk --
	I don't know if this is typical or not).  I have not yet had AC
	power fail on a running system...I would like to see some disk
	manufacturer offer disks for the Unix PC that would automatically
	retract the heads.

2.	/usr/adm/unix.log picks up an entry about once every day and a half.
	I was told by AT&T that these are soft errors.  I imagine the error
	rate depends on system usage and the condition of the disk.

3.	When running the terminal emulator (async-main), quite often the
	call screen pops up and then there is no way to resume or hang up
	the call other than to physically unplug the line (I was told by
	AT&T that there is a related problem here with getty being respawned
	repeatedly).  The best workaround is to use cu.  Also, there are
	cases when, after someone has dialed in remotely, the system
	seems to be in a confused state and cannot be switched successfully
	to VOICE or DATA.  The only solution I know of is a hardware reset.

4.	Is anyone running their Unix PC in a high-temperature environment
	(greater than 80 degrees F.) for any length of time?

4.	RE: USENET NEWS SOFTWARE: postnews and other programs kept aborting
	with a core dump.  I tracked the problem down to the use of the
	identifier 'sigtrap' in rextern.c  The problem was solved by simply
	renaming all instances of 'sigtrap' to 'sigtrp'.  It seems that
	even something like:

		int sigtrap;
		main() { system("exec vi + tempfile"); }

	will abort with a core dump.

		...decvax!tektronix!ogcvax!omssw2!argent!safari!dave

res@ihlpl.UUCP (Rich Strebendt @ AT&T Information Systems - Indian Hill West; formerly) (05/31/86)

In response to:

> The 20MB drive on my Unix PC is also quite loud.  Does anyone know if this
> is also the case with the larger capacity disks offered for the Unix PC?

I am running a UNIX PC/3B1 with the 67MB drive.  This drive is very
quiet.  The only sound from it is a sort of clicking sound when it is
doing seeks (from the stepper motor?).

> I've been running my system continuously for about 8
> months and am extremely pleased with the quality and speed of the machine.

I have not had mine for that long, but I also am VERY pleased with it.

> 3.	When running the terminal emulator (async-main), quite often the
> 	call screen pops up and then there is no way to resume or hang up
> 	the call other than to physically unplug the line (I was told by
> 	AT&T that there is a related problem here with getty being respawned
> 	repeatedly).  The best workaround is to use cu.  Also, there are
> 	cases when, after someone has dialed in remotely, the system
> 	seems to be in a confused state and cannot be switched successfully
> 	to VOICE or DATA.  The only solution I know of is a hardware reset.

With regard to the pop-up call screen while running the terminal
emulator.  The recovery procedure several of us here have been using is
much less drastic:
 1) Select the [w] icon at the top of the screen with the mouse.
 2) A menu will be displayed with entries like the following:
	
	Office of <login>
	Call Screen		or something to this effect
	Async VT100 Emulator
    
    Select the "Async VT100 Emulator" line
 3) Resume your terminal session.  The call screen and the list of
    active windows will both be gone and the emulator will be in
    control.  I have observed no untoward side effects of this
    procedure.

					Rich Strebendt
					...!ihnp4!iwsl6!res