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NeXT Hardware Peripherals FAQ

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Subject: NeXT-Hardware-Peripherals-FAQ
Date: 6 Mar 1995 08:39:17 GMT
Organization: Yale University, Department of Computer Science, New Haven, CT
Lines: 1034
Approved: [email protected]
Expires: Fri, 7 Apr 1995 00:00:00 GMT
Message-ID: <[email protected]>
Reply-To: [email protected]
Summary: Frequently Asked Questions about NEXTSTEP and NeXT machines.
Originator: [email protected]

Archive-name: NeXT-Hardware-Peripherals-FAQ
Last-modified: Mon Mar  6 03:03:59 EST 1995
Version: 3.1

These FAQs are under significant construction,
and may well change form and content over the
next weeks.

These FAQs focus on various aspects of OpenStep,
NEXTSTEP, and NeXT machines.  

The FAQs are kept on-line at several ftp sites,

Many FAQs, including these, are available (www, ftp,
email) on the archive site in the
directory pub/usenet/news.answers.  The name under
which this FAQ is archived appears in the
Archive-nameline above.

Within each section each question will be preceded by
a "Subject:" field, allowing news readers to break up
the file into separate questions.  Each question has
its own unique number. Items that appear within
sections are not in any particular order, and get added
and removed over time.  Questions marked with a "+"
are new to this issue, and questions with changes since
the last issue are marked by a "!".

Submissions, corrections, comments, input, etc.,
should be directed to Nathan Janette
<[email protected]>. 

Some important NEXTSTEP & OpenStep Information WWW sites:

NeXT, Inc.


Stepwise NEXTSTEP/OpenStep Information Server


M1.		What disk drives will work with the NeXT?
M2.		How do I customize BuildDisk to create a bootable disk of my own configuration?
M3.		How much disk space is lost due to formatting and file system overhead?
M4.		Can I run my SCSI-2 disks in synchronous mode?
M5.		How do I configure my HP 660 to boot properly?
M6.		What is the procedure for installing a Fujitsu M2263SA/SB SCSI Disk as the NeXT Boot Disk?
M7.		How do mount a corrupted OD that won't automount?
M8.		What non-NeXT CD Players that work with a NeXT?
M9.		What are some other sources of toner cartridges and trays for the NeXT laser printer?
M10.	What printers (laser or otherwise) may be used with a NeXT?
M11.	What can I do to prevent my NeXT printer from running all the time?
M12.	What type of microphones will work with the NeXT?
M13.	How do I connect a modem to the NeXT?
M14.	Are there any alternative sources for the SCSI-II to SCSI-I cable required to attach external SCSI devices to the 040 NeXTs?
M15.	What fax modems will work with the NeXT?
M16.	How may I attach more than two serial ports to the NeXT?
M17.	What is the best and/or cheapest way to connect a NeXT to a thick Ethernet? 
M18.	How can I connect my NeXT to the telephone line and use it like an answering Machine? 
M19.	What color monitors can I use with the NeXT color machines?
M20.	Where can I get 13W3 to BNC adapters to connect third party color monitors? 
M21.	How may I attach Centronics or 16 bit wide parallel ports to the NeXT?
M22.	Why does an unused serial port consume cpu?
M23.	How to adjust MegaPixel Display brightness and focus?
M24.	How to set up the HP LaserJet 4M?
M25.	My NeXT laser printer fails to fully eject the sheet - how to fix?
M26.	I'm trying to initialize a QUANTUM ELS170S on a NeXTStation and get sd2: Incomplete disk transfer?
M27.  	What are the NeXT mouse connections and alternatives?


Subject: M1. What disk drives will work with the NeXT?

Most SCSI disk drives will work without modifying /etc/disktab. 

There are problems with the installation of boot blocks and badly
formed fstab generated by BuildDisk of NEXTSTEP 2.0.  A disk connected
to the NeXT will need to have a NeXT specific label written to it before it
can be properly recognized by the system.  If you get an error message
"Invalid Label..." this indicates that the drive was successfully
seen by the NeXT machine but it does not have the proper label, to install
a label use the /usr/etc/disk program on the raw disk device that the
system assigned to the device and use the label command to write the
label onto the disk. [how the NeXT assigns disk devices is explained in
the N&SA manual]  

NEXTSTEP releases 2.0 and up provide a low level disk formatter,
sdform, which does not offer much flexibility, but gets the job done. 
Most drives are already formatted at the factory.      


Subject: M2. How do I customize BuildDisk to create a bootable disk of my own configuration?

The BuildDisk application is extremely limited in terms of the  types of
disks configuration it knows how to build.  Essentially it "knows"
about swapdisks, optical disks, 330 and 660 MB SCSI disks. If you wish to
do custom configurations you should look at existing BLD script files
in /etc/BLD.*  There is a script which you can use to specify which BLD
script you are using, which disktab entry, and other useful parameters
in /usr/etc/builddisk 

Some things to note: - the fstab installed on the target disk is
specified in the newclient command in the BLD script.  standard fstabs
are extracted from /usr/template/client/fstab.* - the BLD scripts do
not put down a new boot block on the scsi disk, you may want to install one
by hand using the /usr/etc/disk program. - some disks boot fine but
NeXTstep comes up with a blank window and no login window.  This is due
sometimes to forgetting to install an accessible
/NextLibrary/{Fonts,Sounds}  In general you need quite a lot of things
to make a bootable disk.   

Mike Carlton adds - you can build a minimally usable bootable floppy
(for crash recovery purposes).  There is a modified version of
builddisk (to make it support building floppies, a minimal change) and
a BLD script to build the boot floppy available at in
next/sources/Bootfloppy.tar.Z.  (I put this together in response to
several requests.)  A newer version of Bootfloppy for 2.1 is on the
archives as next/sources/util/Bootfloppy2.1.tar.Z     

[From: Carl Edman <[email protected]>]

Also available from the archives is BootFloopy 3.0 (for -- you guessed
it -- NEXTSTEP 3.0).  I might also add that one can improve on disk usage
while enhancing functionality.  BuildDisk (which is used by the
various BootFloppy scripts) just copies the standard binaries for ls,
mv, cp aso. from /bin.  These binaries are statically linked as shipped
by NeXT which makes them huge. (e.g. /bin/ls is 106496 bytes large.
/usr/local/bin/gls with more features is just 16268 bytes). If you
replace these binaries by the BSD or GNU equivalents you can save
several hundred kBytes on your boot floppy.  This extra diskspace can be
used for tar, dump and more tools which makes the boot floppy actually
usable. Tested. 


Subject: M3. How much disk space is lost due to formatting and file system overhead?

[From: Rex Pruess ([email protected])]

Let's assume you bought a disk drive advertised with 400 MB unformatted
capacity.  Vendors are not consistent with the MB definition.  You may
have much less space less than you think you have.  Which of the following
did you buy?    

         400 * 1000 * 1000 = 400,000,000 bytes
         400 * 1024 * 1000 = 409,600,000 bytes
         400 * 1024 * 1024 = 419,430,400 bytes

The disk must be formatted.  This is often done by the vendor, but
occasionally by the user.  Formatting maps the disk into sectors.  Space
is reserved for the disk geometry and bad sectors.  Formatting can take
10-20% of the capacity depending on the sector size.  Common sector
sizes are 512 and 1024.  Generally, bigger sectors mean less waste.

Once formatted, the UNIX file system must be created.  On the NeXT, this
is one of the steps performed by the BuildDisk application.  It invokes
the mkfs command to make a file system.  This reserves space for the UNIX
file system (e.g., superblocks, inode tables).  This overhead can take
another 2-3% of the available disk space. 

If you issue the df command, you may be surprised to see another 10% the
available disk space has disappeared.  The df command shows the total,
used, and available disk space.  The df units are in kbytes (1024 bytes).
The sum of the used and available numbers will generally be about 10%
less than the total kbytes.  This space is reserved to allow the UNIX file
system to be efficient in its storage allocation.  If your disk fills up,
only the superuser can store files in the remaining 10%.     

To complete the picture, here's a snapshot of what may occur:

	 Capacity	Lost/Used/Reserved	Reason
	(in bytes)	(in bytes)
	419,430,000	19,430,000		Marketing hype (~5%)
	400,000,000	60,000,000		Formatting (~15%)
	340,000,000	 6,800,000		UNIX file system (~2%)
	333,200,000	33,320,000		Efficiency & superuser (~10%)

For more information, refer to the df and mkfs man pages.


Subject: M4. Can I run my SCSI-2 disks in synchronous mode?

Quick answer is: No.  The reason is that the NeXT does not support
synchronous transfers from the SCSI bus.  It does support SCSI-2 disks
running in asynchronous mode, which all SCSI-2 disks must do.    


Subject: M5. How do I configure my HP 660 to boot properly?

It has been reported that HP drives fail to autoboot on power on or while
other devices are on the scsi bus.  The problem seems to be with drives
configured to spin-up automatically on power on do not get recognized
at boot time.  To remedy this problem reliably with HP 660Mb (HP97548)
and 1Gbyte (HP 97549) drives remove the auto spinup jumper on the back of
the drive.  Looking at the disk from the back with the power connector on
the lower left, it is the sixth jumper.    

[From: [email protected] (Jimmie Quan)]

The offical fix was an EPROM change to the HP drive from HP. The HP drives
took too long to wait up, so the system wasn't happy with the other drives
coming ready first especially when the HP was suppose to be the boot
device. (The EPROM is no longer available from NeXT).  


Subject: M6. What is the procedure for installing a Fujitsu M2263SA/SB SCSI Disk as the NeXT Boot Disk?

See Izumi Ohzawa's note in /pub/next/docs/fujitsu.recipe available via
anonymous ftp from   


Subject: M7. How do mount a corrupted OD that won't automount?

If you can't automount an OD, and you can't fix it, you can still manually
mount it.  Log in as root.  Type "/usr/etc/mount /dev/od0a /FoO".  It will
ask you to insert the disk.  Insert it.  It is mounted.

This method WILL mount a corrupted OD so you can read its contents.  Since 
it is corrupted, it is not recommended to write to it.  You should copy the 
important files to something else, then reformat it.    


Subject: M8. What non-NeXT CD Players that work with a NeXT?

A USENET survey summary:

Apple CD-150
PLI 1035N for NeXT
SUN CD-ROM drive (Sony CDU-8012, Rev. 3.1a)
NEC 73M and 74 (transfer rates > of 300 KB/sec.)
Apple CD-SC (Sony 541-22 mechanism)
Chinon CDS-431 (with new drivers)
Eclipse CD-ROM from Microtech
Toshiba 3201
Toshiba 3301
Toshiba 3401
Toshiba TXM3301E1
Toshiba XM-2200A external
DENON DRD-253 external (data only, no music)
HP's LaserROM drive (Toshiba XM-3301TA drive in HP's box)
Texel 3024 (required a firmware upgrade to version was 1.11)


Subject: M9. What are some other sources of toner cartridges and trays for the NeXT laser printer?

The toner cartridge is a standard EP-S cartridge, the same that fits the
HP LaserJet III and some other printers.

[From: [email protected]]

Any HP LaserJet II or III will fit.  HPLJ4mSI cartridges do NOT fit.

Any HP LJII or LJIII paper tray will fit.  IIISI and 4 trays will not. 


Subject: M10. What printers (laser or otherwise) may be used with a NeXT?

If you plan to connect an HP LaserJet (II, IIP, III, etc.) you need to make
a special cable in order for the NeXT 040 and HP to get the hardware
handshaking correct.  This is true for whatever version of the OS you are

NeXT 68040 to HP LaserJet III Cable (not a Null-modem cable):
	Mini-Din       HP DB-25
	1   (DTR)      nc 
	2   (DCD)      4  (RTS)	
	3   (TXD)      3  (RXD)
	4   (GND)      7  (GND)
	5   (RXD)      2  (TXD)
	6   (RTS)      5  (CTS)
	7   (RTXC)	    nc	     
	8   (CTS)      20 (DTR)

You may want to use hardware flow control for reliability (ie

If you have problems with other printers, check the cable pinouts in the
printer's manual against the one recommended in the zs man-page!   Refer
to Chapter 13 in Network and System Administration.

See the FAQ-NEXTSTEP-Printing for software config FAQs.


Subject: M11. What can I do to prevent my NeXT printer from running all the time?

The NeXT 400dpi printer powers up every time you boot up when the print
daemon is started (/usr/lib/NextPrinter/npd in /etc/rc).  Apart from
not running the daemon at boot time (commenting it out and having to run
it by hand later), you can add the following lines to /etc/rc.local:    

	if [ -f /usr/etc/nppower ]; then
		sleep 3
		/usr/etc/nppower off
		(echo 'powering off NeXTprinter')		>/dev/console

Once you queue a print job the printer daemon will automatically power
up the NeXT printer for you.  The printer daemon will not automatically
power off the machine after a print job, you will need to turn off the
printer by typing /usr/etc/nppower off.    


Subject: M12. What type of microphones will work with the NeXT?

Some NeXT owners use the RadioShack (Realistic) Tie Clip Microphone
($19.95) cat 33-1052.  NeXT Computer, Inc. uses the "Sony Electret
Condenser Microphone ECM-K7" in-house (available for ~$60).  Some use
Sony Tie-Clip microphone, #ECM-144, which costs around $40.  Others
have successfully used a WalMart brand microphone (available for


Subject: M13. How do I connect a modem to the NeXT?

Previously, we suggested that people use Mac modem cables; however, it
has come to our attention that there is no one standard Mac modem cable. 
Since correct modem operation on a NeXT depends upon a correctly wired
modem cable, buying a Mac cable is not a good idea.  Some Mac cables do not
allow dial-in and no Mac cable allows the use of hardware flow control. 
For these reasons, we are recommending that only cables that meet NeXT
specifications be used. [however, if you have a Mac modem cable lying
around and don't care about dial-in or hardware flow control, then by
all means....]

These cables are available commercially from NextConnection, and
from Computer Cables and Devices, or can be custom built.  Note that no
off- the-shelf Mac cable will allow hardware flow control.  It is
however possible to make a such a cable from an Imagewriter II cable by
replacing one of the mini-8 ends with a DB-25 connector.  

Hardware flow control is absolutely essential for all serial port
connections with speeds of 9600 bps and above. Make certain that you
cable supports it, your modem is configured to use it and you are using
the hardware flowcontrol devices /dev/cuf[ab], /dev/ttydf[ab] and
/dev/ttyf[ab], respectively.  

Most people use tip or kermit to control the modem.  SLIP and/or UUCP may
also be used (but are more complicated to set up and require the remote
machine to also have SLIP and/or UUCP (respectively)).

The 2.0 Network and System Administration Manual, which is available
in hard-copy (shipped with each machine) contains an extensive
description of how to use modems with the NeXT machine.  Additionally
NeXT in their TechSupportNotes series called SerialPortDoc.wn and
UUCP for 1.0/1.0a systems .  This document is available from most FTP
sites that carry NextAnswers.  Also, try to obtain the about.modem.Z
file by Mark Adler in the pub/next/lore directory on 


Subject: M14. Are there any alternative sources for the SCSI-II to SCSI-I cable required to attach external SCSI devices to the 040 NeXTs?

Yes.  This cable is the same as the one used by Sun SparcStations and
DecStation 5000's (but not DecStation 3100's which use 68-pin micro
rather than the 50pin micro connector used on NeXT 040, Suns and
DecStation 5000).  

[Carl Lowenstein adds]

The implication that a Sun SparcStation cable can be used with NeXT
peripherals is generally false.  NeXT themselves, and DEC, and nearly
everyone else who makes SCSI peripherals, puts Telco-50 (centronics)
connectors on their devices.  Sun in their infinite wisdom uses DD50
which are quite different.  Telco-50 is an approved connector type in
the SCSI spec.

Probably the original point was that the 50-pin microSCSI on the NeXT
and Sun and some DecStations was different from the 68-pin microSCSI on
the DecStation 5000.  But this does not address the other end of the


Subject: M15. What fax modems will work with the NeXT?

The following fax modems are currently available for the NeXT Computer:  

Manufacturer, Model Supplier, Phone		Avail.  Type
DoveFax for NeXT, Dove Computer, ???		Now     Class 1
HSD FaxMaster, HSD Microcomputer, 800-828-5522	Now     Class 2*
mix fax, i�link GmbH, +49 30 216 20 48		Now     Class 2**
[From: Robert Wong <[email protected]>]

SupraFAXModem V.32bis, Supra Corp., 1-800-727-3564, Now, Class 2
  (requires DFax driver or NXFax driver)
ZyXEL U-1496E/E+/S/S+, ZyXEL USA, 1-800-255-4101, Now, Class 2
  (requires NXFax driver)
Telebit T3000 with fax option / Telebit WorldBlazer with fax option
  (requires NXFax driver)
Neuron 1414 / 1414+ with ZyXEL ROM upgrade
  (requires NXFax driver)
  (Neuron 1414 and Neuron 1414+ modems are relabelled ZyXEL modems.  
   Contact ZyXEL USA for ROM upgrades.  Neuron modems with 512K ROMs 
   should upgrade their ROMs and ROM sockets to 1 Mb ROMs.  People 
   with 1Mb ROMs should just order the new ROMs.)

(*)Note that the Class 2 is not yet approved; it is still out for ballot,
after having failed in an October 1990 round.  The Abaton InterFax 24/96
NX driver supports Class 2 as it was in that draft;  there are expected to
be very few changes prior to approval.

(**)Note that mix fax works with both the October 1990 and October 1991
draft versions of Class 2, especially with the NeXT supplied Class 2
modem driver. Upgrading to an approved version of  Class 2 would be a
matter of just a software update (holds true for any forthcoming (class
3?) standard, for that matter). 

In order to use a fax modem with the NeXT Computer, a NeXT compatible fax
driver must be available to operate the modem.  Modem control
procedures may be proprietary or conform to one of the following
EIA/TIA standards:   

Class 1: CCITT T.30 session management and CCITT T.4 image data
handling are controlled by the driver.

Class 2*: CCITT T.30 session management and image data transport are
handled by the modem.  CCITT T.4 image data preparation and
interpretation are controlled by the driver. 

Release 2.0 of the NeXT system software includes a Class 2 modem driver
which will work with any fax modem which meets the EIA/TIA Asynchronous
Facsimile Control standard.  Other fax modems must supply a NeXT
compatible driver.  

The following are notes by Alan Marcum of NeXT Tech Support  concerning
the Class 2 modem driver: 

	Note that there's a small bug in 2.0 (fixed in 2.1): a
	symbolic link is missing for the file
	Class2_Fax_Modem_Driver in /usr/lib/NextPrinter.
	The simple fix: create the link; it should reference
	Interfax_Fax_Modem_Driver, also in the
	/usr/lib/NextPrinter directory. 

	An alternative workaround for Class 2, especially
	useful for  novices: just use InterFax as the modem type in
	PrintManager, rather than Class 2*.

	After installing a fax modem using PrintManager one must
	repeat setting things in the Fax Options panel in order
	for them to be stored correctly. In particular, these
	include the Rings to Answer and Number of Times to Retry. 
	This affects all fax modems being installed.

	If one uses illegal characters in the Modems Number field
	in the Fax Options when configuring an InterFax modem
	then the modem will not answer the phone.  Legal
	characters are digits, spaces, and plus signs (+).  This
	does not affect the Dove modem. 


Subject: M16. How may I attach more than two serial ports to the NeXT?

TTYDSP From Yrrid converts the DSP port into an additional serial port.

	Yrrid Incorporated
	507 Monroe St.
	Chapel Hill, NC 27516
	Voice: 919-968-7858
	Fax: 919-968-7856
	Email: [email protected]

Unitnet has a device, the SLAT, that will connect to the scsi bus.

	Uninet Perhipherals, Inc.
	Voice: 714-263-4222
	Fax: 714-263-4299

[[email protected] (Mike Heins)]

Central Data Corporation makes the scsiTerminal Server
family of products.

Drivers for NextStep 3.0 and 3.1 are available for both the 68K-based
and Intel-based platforms.  The products available for NeXT include:

       Product         DESCRIPTION

       ST-1002+        2 serial, 1 paralllel
       SP-1003         3 parallel
       ST-1008+        8 serial, 1 parallel
       ST-1016         16 serial
You can also mix and match multiple units.

	Phone:      217/359-8010
	Toll-free:  800/482-0315
	FAX:        217-359-6904
	Email:      [email protected]
                    [email protected]
                    [email protected]

VISA, Master Card, and American Express orders are accepted, as well as
purchase orders from accredited corporations and institutions.  We
are on a GSA schedule, and there is a 25% educational discount. 

[Jacob Gore adds:]
Also, one can use an IP terminal server.  In a non-Internet environment,
inexpensive terminal servers, which don't control access to the
network securely, can be used.  If your network is an Internet subnet,
you must use a terminal server that controls either: (1) who can log into
the terminal server, or (2) which machines the terminal server will
access.  These tend to be more expensive (around $250/port, but in
8-port increments), but it may be quite economical means of sharing
ports among many NeXTs (or other computers) on the network.   

[Eric P. Scott adds:]
Particularly if one has a NeXT network, an Ethernet terminal server may
be the way to go.  One that supports Linemode Telnet (such as the Xylogics
Annex III) will offer the best performance.  


Subject: M17. What is the best and/or cheapest way to connect a NeXT to a thick Ethernet? 

There are many possible solutions.  For example, here are three: 

1) The University of Waterloo [Audio Research Group] uses an old
door-stop PC XT clone with two Western Digital cards (WD8003E
Ethercard Plus, $250 CDN each; you should be able to get them for under
$200 (US$)) running Vance Morrison's PCRoute (available from You will also need a thickwire transceiver and a
drop cable (about $300). In addition, you will need Internet addresses
for the NeXT and both PC Ethernet cards (and a subnet address).  The
documentation for PCRoute contains quite a bit of information on the
performance of this setup. This solution requires two subnets.  There
is another program called PCbridge that allows the machines on the thin
and thick wires to be part of the same subnet.  This product also does
packet filtering, so that packets destined to machines on the same side
of the net do not cross over.   

2) Cabletron sells a MR-2000C Singleport Repeater for $695 that does
exactly what you need minus drop cable and transceiver.  Their number  is
(408) 441-9900.

3) The march 1992 INMAC networking and connectivity products catalog
lists thicknet to thinnet convertors. Product number Z903071 price
$445. Claims full ieee 802.3 comaptibility and diagnostic LED's.   


Subject: M18. How can I connect my NeXT to the telephone line and use it like an answering Machine? 

A company that is selling both hardware and software to allow you to do

	SES Computing
	13206 Jenner Lane
	Austin, Texas 78729
	Voice: (512) 219-9468 (Demo system number), a european company, has a combined data/fax modem and
telephone answering machine. It uses the DSP port and is implemented
mainly in software on the DSP with a little bit of hardware to interface
to the phone line. GmbH
	Nollendorfstrasse 11-12
	D-1000 Berlin 30
	Tel: +49 30 216 20 48
	Fax: +49 30 215 82 74
	Email: [email protected]


Subject: M19. What color monitors can I use with the Color NeXT machines?

The important specs for the color monitor are:

	Horz Scan Rate:		61 KHz
	Vertical Scan Rate:	68 Hz
	Resolution:		1280x1024 (NeXT uses 1120x832)

Displays may require alignment to adjust for the scan rate of NeXT machines.

Some monitors reported to work well include:

	Sony GDM-1601
	Nanao T560i
	IBM 17P

[From: William Shipley <[email protected]>]

Note that you need the 13W3 to BNC cable to connect a 3rd party monitor to a NeXT.

The monitor must have BNC connectors (most high end ones do), and must sync on green. Ideally it should have a P22 phosphor (persistence) and a white point of 9300 Kelvin. 


Subject: M20. Where can I get 13W3 to BNC adapters to connect third party color monitors? 

From NeXT/Bell Atlantic(?): part number S4025.

NuData in New Jersey carries 13W3 female to 4 BNC male connectors. The
price is about $100.  

	Voice: 908-842-5757

[From: Robert Nicholson <[email protected]>]

DISCLAIMER: I take no responsiblity for the following.

If you can source the bits yourself here's how it's built.

1 female 13W3 connector
3 Male BNC connectors
3 mini coax 

ie. the pins to the coaxials are male and the regular pins are female.

Looks like this.

    .   o o o o o .     .        13W3 FEMALE
    A1 o o o o o A2     A3

    |             |     |	

    Red           Green Blue     3 BNC's

That's the coax part.

The outer shielding of the coax's are grounded on both pin 10 and the case.


Subject: M21. How may I attach Centronics or 16 bit wide parallel ports to the NeXT?

Uninet has devices, the SLAT-2 and the SLAT-DRV11, that will connect to
the scsi bus. 

        Uninet Peripherals, Inc.
        Voice: 714-263-4222
        Fax: 714-263-4299
        [email protected] or uunet!ucivax!zardoz!sales


Subject: M22. Why does an unused serial port consume cpu?

Perhaps you've got a (probably fairly long) unshielded serial cable
attached to it, with either nothing at the other end or a powered-off
device at the other end.  EE's call this an antenna.  it's probably
picking up most of the radio stations in your area, which the serial chip
is interpreting as a continuous stream of garbage bytes, which it feeds
to getty, which tries to interpret them as login attempts.  

How do you avoid this problem?

- leave the device at the other end switched on (even when it's not
transmitting, it will assert a voltage that overrides the noise)

- unplug the cable from the next when you're not using it

- use 'kill -STOP' & 'kill -CONT' to stop & resume the getty process as

- buy an adequately shielded serial cable 


Subject: M23. How to adjust MegaPixel Display brightness and focus?

[From: Charles William Swiger <[email protected]>]

I have adjusted several monitors with no problems, but make sure you
know what you are doing before opening anything.  I expressly disclaim
responsibility for any ill results that may occur.

In order to adjust NeXT's MegaPixel display (called 'the monitor'
hereafter), you'll need (a) the NeXTtool (or a 3mm Allen wrench), (b) a
plastic adjustment tool (preferred) or a thin bladed screwdriver, and
possibly (c) a Phillips-head screwdriver.

(NB: A similar procedure will work for color monitors, but you should
either know what you're doing or you'll probably be better off letting a
pro deal with it.)

Turn off the computer.  Disconnect all cables to the monitor.  Look at the
back of the monitor.  There will be 4 screws there; use the NeXTtool (or
Allen wrench) to remove them.  Remove the plastic back of the monitor and
put it out of your way.

Reconnect the cables and turn the computer back on.  As the machine
powers up, examine the back of the monitor.  You'll see a metallic box
(usually silver, though some are black) surrounding the monitor's
vitals.  This protects you against the dangerous voltages inside, and
also insulates the monitor from electromagnetic noise.  On the back of
this box are several holes for performing adjustments.  There are two
focus controls (labeled 'focus' and 'dynamic focus'), a brightness
control (labeled 'brightness' or possibly 'black level') and several
others that adjust various things like screen size and position.

Depending on the exact placement of the controls on the circuit board of
your specific monitor, some of these controls may be difficult (or
impossible) to adjust from the back.  If this is the case, I will describe
what's necessary below.  Otherwise, adjust the appropriate controls
using either an adjustment tool or a screwdriver.  Be warned that a
screwdriver probably will cause some interesting video effects when
it enters the case.  Ignore this the best you can, or find a plastic
adjustment tool, which is what you *really* should be using anyway. 
Using a flashlight will help you see into the hole so that you can align
the business end of the tool correctly.

Focus and position controls are fairly obvious.  Adjust them slowly
until you're happy with the results.  Don't muck with anything you don't
need to; the factory settings are usually pretty decent.

To correctly adjust the brightness, follow this procedure: Turn the
brightness of the monitor all the way down using the keyboard.  Adjust
the brightness control on the back of the monitor until a barely
noticeable picture forms.  Then turn the brightness down a little so
this picture disappears completely.  Check that you can get adequate
brightness by using the keyboard to brighten the screen.  If the display
isn't bright enough, adjust the brightness control on the rear of the
monitor high enough so that the monitor display is adequate.  Note that
you won't be able to dim the screen completely from the

Once you're finished, shut down the computer, take off the cables,
reattach the back of the monitor, and reconnect the cables.  You're

If the control you need to adjust proves to be difficult, you may need to
enter the metal case.  This happened on one monitor's focus control and
another's brightness.

INJURE OR EVEN KILL YOURSELF.  Do not perform the next instructions
unless you are confident that you know what you are doing.

You'll have to power off the computer again, and disconnect the cables.

Looking at the monitor from the back, notice a section of metallic
shielding on the right side of the metal box that extends to the picture
tube.  This is where the flyback transformer is connected.  It shields a
wire that is charged to about 25,000 V.  DO NOT TOUCH THIS WIRE, IT CAN
SHOCK YOU THROUGH ITS INSULATION.  Being very careful of this, remove
the metal case by unscrewing the Philip's head screws that hold the case
on.  Don't touch the screws that hold the picture tube into the front of
the monitor's case.

Once you've gotten the metal box off, reconnect the cables.  Figure out
what control you're going to adjust, and make sure that you can do so
without touching anything else inside.  Again, *watch out* for the wire
that connects to the picture tube on the right side.

Power up the computer.  I recommend that you use only one hand to make the
adjustment, and that your other hand be placed in your pocket (or
similar equivalent, if you're wearing clothes lacking pockets).  This
precaution reduces the chances that you'll make a short circuit
between one hand, your heart, and the other hand-- a good idea.  Perform
the necessary adjustment(s), being very careful not to touch anything
inside.  Then shut down and reassemble the monitor, following the
directions given above.

Hopefully, these instructions will prove useful.  Once again, please
be very careful...I don't want your death and/or injury on my
conscience (or a lawsuit, for that matter, either :-)


Subject: M24. How to set up the HP LaserJet 4M?

[Samuel M. Goldberger	[email protected]]

I solved the problem by building a serial cable based upon the pinouts
supplied  by HP in their manual. Please note that the LJIII cable *does
not work*. In  particular, pin 1 from the DIN plug must be connected to pin
6 of the DB25. I  used 38500 bps on both sides, and the 600 dpi ppd.

Emulex offers the NETJet network interface which speaks lpd protocol,
unlike the HP unit. 


Subject: M25. My NeXT laser printer fails to fully eject the sheet - how to fix?

[From: [email protected] (Jerry Stubbs)]

If you continually get messages like, "sorry, the printer is jammed"
and you have to pull each page out the last inch, you probably need
to replace the 14 tooth gear in the output stage(fuser ass'y).

You can see this gear before you disassemble the printer, so that is
a good first step. Then read these instructions all the way through
and see if you want to attempt it. Next recommends replacing the 
entire fuser assy ( big bucks) if the gear is damaged, but Chenesko, 
Inc., of Ronkonkoma, NY sells the gears for $2.31. The part number
is RS1-0132.  They recommended I also replace the 20 tooth gear, number
RS1-0116, but I don't know if it is really necessary. Their phone 
number is 800-221-3516.

To examine your gear, open the rear (delivery ) door and undo the screw
attaching the strap that keeps the door from opening down all the way.
The gear is on the side nearest the power input to the printer.

THere are two gears on the part of the delivery ass'y that swings down.
The suspect gear engages the top one, but is mounted on the fixed portion
of the fuser. Ours had several teeth missing and/or damaged. To get the
gear off you have to remove the fuser ass'y.  TO remove the fuser you 
must open the printer lid fully, so it is straight up. To open the lid
fully you must remove the case. To remove the case you must remove the
plastic cover on the lid. 

Are you getting the idea now?  THis will be a lot of fun, and take 
most of the afternoon. I hope you have a  spacious, well-lit area,
because there are a lot of screws, and a lot of them are painted 
black, so they are hard to see when you drop them, unless you drop 
them inside of the printer, where you might NEVER see them again. 

Fortunately, as with all computer equipment, they seem to put lots 
of extras in, so just make sure there aren't any where they might 
do damage, like short out the mega KILOVOLT corona power supply,
or grind into the REGISTRATION rollers. You do want your printouts
to be straight, don't you?

So, if you're ready, here we go.

Most mere mortals will want to power down everything and disconnect the
cables, etc. Remove the cartridge and paper trays, etc.

open the lid and remove 3 screws. They DO NOT have any red paint on

there is one screw that holds the strap. When you can swing it clear
down, you can squeeze the hinges together and remove the door.

There are maybe seven screws that hold the case on. Four are right on
top. Two are just inside the rear door area. Two are down inside where
you store that green cleaning tool. 4 + 2 + 2 = 7, right? Say, who
was the last guy that worked on this printer anyway?

The case has to be convinced that you really need to remove it, even
when it is loose and all the screws are out. 

You will need a PHILLIPS screwdriver for this, as with the previous 
steps. But you will need a LONG one this time.  Three of the screws 
are pretty easy to find. Just study the lower part of the fuser, 
as it is screwed onto the bottom case. Two of the screws are inside.
One is under the lid next to the gears, the other near the green 
cleaning tool. On the outside, in back, there is one on each side.
One is under the white wires that connect the fuser to the 10 AMP
circuit breaker,which is pretty near that gear, and close to
the power input. Unplug that cable. Then remove the small black
screw that holds the black plastic gear cover so you 
will have better access to the last screw. Then you will have to 
wrestle the fuser out the back of the printer.  Be careful with it.

There are several screws and a spring. It's not too hard to take 
apart. You can see the gear, so you just have to take off the
covers on that end of the ass'y to get to it. I should caution
you that I had trouble putting them back on, because they have
funny shapes and don't make a lot of sense. Plus I was tired,
so I went home, ate dinner, played with the dog, went to bed, got
up and ate breakfast before I put it back together. You might want
to label some parts, make some drawings, etc. to reassure yourself
that you can put the parts back just like they were.

You can remove the gear pretty easily with a small screwdriver by 
unspringing the "E"-ring that holds it on the shaft. Try not to
bend the e-ring. 


Sorry, I can't help you with this part (HA HA!) I told you 
you should read the instructions first.  Maybe you should
buy a new printer, or try to attach some third party printer via
the serial port!

Well, if you got this far I hope you dropped little crumbs of 
bread so you can find your way back. I try to save all the 
little screws by putting them back in the holes they came from,
or putting them in some small container. You might clean some
of the gears or the paper path while you have it open. You can
also install a new OZONE filter. Remember OZONE is hazardous 
to your health, so you don't want to inhale it.

Be careful if you try this procedure. There are dangerous voltages
present, and even if you are too chicken to work on it powered up,
you could cut yourself, or drop the whole thing on your foot, 
thus voiding the warranty. Also, the printer won't work without the
covers, because there are two secret switches that inform the 
NeXT cpu that someone "is fooling around with the printer again".

Yet another update to reflect that Jacob Gore received gears
for an Apple Laserwriter from Chenesko, which are similar
enough to work, but with some modification.Also, if the original
gear is in fair condition, it can be reversed on the shaft
until a replacement is ordered.


Subject: M26. I'm trying to initialize a QUANTUM ELS170S on a NeXTStation and get sd2: Incomplete disk transfer?

[From: [email protected] (Max Hailperin)]

The Quantum ELSxxxS drives only work with NeXTs if they are the only
SCSI device.  If alone, they work fine, but if there are other SCSI
devices you get "incomplete disk transfer" messages.

Subject:  M27. What are the NeXT mouse connections and alternatives?

[From: [email protected]]

Thanks to Alvin Austin ([email protected]) I have the information I
need on the NeXT mouse connections.

	Pin	Function
 	 1	+5v
 	 2	X Encoder Phase A
 	 3	X Encoder Phase B
 	 4	Y Encoder Phase A
 	 5	Y Encoder Phase B
 	 6	Right Button
 	 7	Left Button
 	 8	Ground

[From: [email protected]]

The MS mouse comes with a "Mini HDIN" 9-pin plug. I found no
way to use this, and had to cut the cable and wire to a mini
DIN 8-pin plug. If you haven't built a cable with an 8-pin
mini DIN before, take the advice that has been offered here
before and don't try to solder to the plug -- get a cable with
bare wires or a cable with the plug on one end (lots of Macs
use these) and cut it.

On to the details. Notice that if the pins weren't numbered
differently, the layout would be approximately the same. The
MS mouse doesn't use switch numbered 2. And there is no
reason I know of that another MS mouse need have the same
color coding, so check it against the pins after cutting the

NeXT mouse wiring:

1       +5V
2       XA
3       XB
4       YA
5       YB
6       right button
7       left button
8       ground
shell   chassis ground


    6 7 8
   3 4   5
     1 2

Microsoft Bus Mouse wiring:

1       switch (2)
2       left switch (3)         Blue
3       ground                  Black
4       XB                      White
5       YA                      Orange
6       YB                      Yellow
7       right switch (1)        Green
8       +5V                     Red
9       XA                      Brown


    1 2 3
   4 5 6 7
     8 9


Editor: [email protected]
Nathan Janette
Systems Manager, Axel T. Br�nger Lab

Internet:	[email protected]