NeXT ROM Monitor FAQ

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NeXT ROM Monitor FAQ v1.2
by hellsh0k, July 2000
Please report any mistakes to

Note:  This document applies only to NeXT-produced 'Black' hardware, including
NeXTstation (Mono, Color), NeXTstation Turbo (Mono, Color), NeXTcube, NeXTcube
Turbo, and NeXTdimention .

Q:  What is the ROM monitor?
A:  The NeXT Computers produced by NeXT, Inc. have two separate system
monitors.  The ROM monitor (the focus of this FAQ) and the NMI mini-monitor. 
Both monitors allow the user to observe and control system procedures.  The ROM
monitor is accessible at startup, while the computer is performing
self-diagnostics and initiating the bootstrap procedure, and it allows the user
to control the system directly using specialized commands.

Q:  How do I access the ROM monitor?
A:  There are two ways to access the ROM monitor.  
  The first way is to hold down the right Command key and the ~ key (with out
Shift) on the numeric-key pad at startup (**IMMEDIATLY** after the 'Testing
System' message is replaced by the 'Loading From Disk' message).  For NeXT
Computers with ADB keyboards, press the Command bar and the ~ key.  The ROM
monitor window should open and you should get a  NeXT>  prompt.  If you are
late and the Login panel appears, power down and try again.
  The second way is to go through the NMI mini-monitor if the computer is
already booted and you are logged-in.  This will be discussed later.
  You will also get the ROM monitor if you try and boot the system, but no
drives are defined, can be found, or are installed.

Q:  Does case matter?
A:  Not really.  As a rule, you should use lower-case, as some thing will not
work upper-case, but I have had success using upper-case on most things.

Q:  What are some of the commands for the ROM monitor, and what do they do.
A:  Depending on what series of EPROM chips are in your computer, the commands
will be slightly different.  For a list of all available commands type ? and
hit enter at the NeXT> prompt.
  Here are some of the main commands, and how to use them:

Configuration Parameters  -  p
Using the  p  command allows you to view and change the configuration of your
system.  You should see something like this:

boot command:  sd?
DRAM test:  yes?
perform power-on system test:  yes?
        sound out tests:  no?
        SCSI tests:  no?
        loop until keypress:  no?
        verbose test mode:  no?
boot extended diagnostics:  no?
serial port A is alternate console:  no?
allow any ROM command even if password protected:  no?
allow boot from any device even if password protected:  no?
allow optical drive #0 eject even if password protected:  yes?
enable parity checking if parity memory is present:  no?

  Q:  What does this mean?
  A:  Each one of the lines is a prompt that will require you to either press
Enter, or enter a value (or string) and then press Enter.

  Q:  What are the parameters for each prompt, and what do they do?
  A:  Here they are:

boot command
Sets the default boot device.  The possible choices are:

en  -  Ethernet (either thin-wire or twisted-pair) or
tp  -  For Twisted-pair Ethernet Only
fd  -  Floppy disk (internal only)
od  -  Optical disk (internal only)
sd  -  SCSI disk

DRAM test
Checks the main memory.  This test can take a while, so it is enabled
separately.  A  y  or  yes  enables it, a  n  or  no  disables it.

perform power-on system tests
The initial parameter can be turned on/off using the  yes/no  commands, as well
as  y/n.  If it is on, then it allows you to perform four additional tests,
turned on/off by the same yes/no commands.
  sound out tests:  causes sound test to be performed.
  SCSI tests:  comprehensive testing of the SCSI interface if a device is
installed (ether internal or external).
  loop until keypress:  runs the diagnostics until it is interrupted by a
  verbose test mode:  displays the name and system message of each test and
step of the boot.  Helpful for diagnosing boot problems.

boot extended diagnostics
Controlled by a  yes/no  y/n  response, it looks for the root file diagnostic
on reboot.  This file is owned and used by NeXT technicians, so this parameter
should always be set to no.

All parameters are stored in non-volatile RAM and will remain even when your
computer is powered down.  Also, you will not be able to change any values
without entering the hardware password if it is set.

Memory Configurations  -  m
The  m  command displays information on the memory installed in sockets 0
through 15 (the original NeXT had 16 RAM slots).  The output should be
something like this:

Memory sockets 0-3 have 4MB page mode SIMMs installed (0x4000000-0x4400000)
Memory sockets 4-7 have 4MB page mode SIMMs installed (0x5000000-0x53fe000)
Memory sockets 8-11 have no SIMMS installed (0x0-0x0)
Memory sockets 12-15 have no SIMMS installed (0x0-0x0)

The measure of MB is the total MB for those groups of slots (The example
computer has 8-1MB SIMMs).

Ejecting Disks  -  ej, ef
the two different eject commands are for the optical and floppy drives.  The 
ej  command ejects an optical disk, while  ef  is used to eject a floppy disk.

Resuming Execution  -  continue,  c
To resume normal execution from where it was halted (the point at which you
entered the ROM monitor, type  continue  or  c  followed by a return at the
NeXT> prompt.  If you have verbose mode turned on, you should get a whole
crapload of information about the different stuff on your computer and the
readiness of all the different components, ending with reboot {computer name}
{time/date}: reboot complete, and then bee returned to the login panel.
Otherwise you will get the standard loading graphics.

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