NetBSD/next68k: Frequently Asked Questions



Other sources of information


How do I get to the ROM Monitor or the debugger?

You can get to the ROM monitor or break into the debugger (once the NetBSD kernel is running) at any time by hitting both COMMAND and the backquote (`) key above the 7 on the numeric keypad.

How do I reset the system without pulling the plug?

This is a hard reset -- it does not sync the filesystems first. Press the left COMMAND-ALTERNATE-* keys (where the * key is to the right of the / on the numeric keypad).

How do I netboot?

This is now covered in the INSTALL notes. There is also a section of the Diskless NetBSD HOW-TO devoted to netbooting NetBSD/next68k.

How do I boot from a second hard drive or CD-ROM?

The ROM Monitor bsd() command defaults to booting from the lowest SCSI ID drive which is usually the internal hard drive at ID 0. To boot from the next SCSI hard drive, you would use bsd(1,0,0) which will boot from the next highest SCSI ID drive -- not necessarily SCSI ID 1.

SCSI ID boot command
0 bsd()
2 bsd(1,0,0)
6 bsd(2,0,0)

Only turbo NeXT systems can boot directly from a CD-ROM. Non-turbo models need to load the bootloader from a floppy, SCSI hard drive, or over the network.

What can I do in the ROM Monitor?

From the ROM Monitor prompt, type ? to get a listing of the possible commands and p to configure the system. Additionally, pressing the Power key will let you power down the system.

To boot from a SCSI disk, type bsd(). To boot from the ethernet, type ben()netbsd.

                        NeXT ROM Monitor 2.5 (v66)

CPU MC68040 25 MHz, memory 100 nS
Backplane slot #0
Ethernet address:  0:0:f:0:fb:90
Memory size 40 MB
NeXT ROM monitor commands:
        p  inspect/modify configuration parameters
        a [n]  open address register
        m  print memory configuration
        d [n]  open data register
        r [regname]  open processor register
        s [systemreg]  open system register
        e [lwb] [alist] [format]  examine memory location addr
        ec  print recorded system error codes
        ej [drive #]  eject optical disk (default = 0)
        eo  (same as above)
        ef [drive #]  eject floppy disk (default = 0)
        c  continue execution at last pc location
        b [device[(ctrl,unit,part)] [filename] [flags]]  boot from device
        S [fcode] open function code (address space)
        R [radix]  set input radix
        [lwb] select long/word/byte length (default = long).
        [alist] is starting address or list of addresses to cyclically examine
        Examine command, eith no arguments, uses last [alist]
Copyright (c) 1988-1990 NeXT Inc

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


How do the keyboard, mouse, and monitor connect to the NeXT hardware?

For monochrome systems (NeXT Computer, NeXTcube, NeXTstation, NeXTcube Turbo, and NeXTstation Turbo) without a NeXTdimension board, a 19 pin cable connects the system to the mono MegaPixel Display. The cable carries power for the monitor, video for the monitor, sound in and out, and the keyboard/mouse connector. The keyboard plugs into the monitor, and the mouse plugs into the keyboard.

For color systems (NeXTstation Color and NeXTstation Color Turbo) a funky "Y-Cable" connects the system to a soundbox and to a monitor. The monitor end of the cable is a 13W3 connector. You can use any multisync monitor (with the appropriate adapter) or a fixed frequency monitor supporting the appropriate refresh rate. NeXTstation Color supports 68 Hz refresh at 1280x1024. NeXTstation Color Turbo supports 72 Hz refresh. The soundbox provides the additional functionality of the mono MegaPixel Display (sound in and out and keyboard/mouse connector). The keyboard plugs into the soundbox, and the mouse plugs into the keyboard.

For cube systems with a NeXTdimension board, the refresh rate is 68 Hz. If the cube is using a mono MegaPixel Display in addition to the NeXTdimension driven display, a simple 13W3 cable is used to connect the monitor to the NeXTdimension. If the cube is not using a mono MegaPixel Display, you must use a "Y-cable" and a soundbox connected to the NeXTdimension board.

Differentiating ADB and non-ADB keyboards and mice

Currently, only non-ADB keyboards and mice are supported.

Non-ADB keyboards use a mini-DIN connector with 5 pins. Non-ADB keyboards have a black power key between the brightness and volume keys. Non-ADB mice use a mini-DIN 8 connector. Non-ADB mice are rectangular. All NeXT hardware supports these peripherals with the original mono MegaPixel Display (N4000 or N4000A) or a non-ADB soundbox (serial number prefix ABN). The ADB monitor and soundbox cables will work with non-ADB monitors and soundboxes. Non-ADB monitor cables (part numbers 150 or 1532) and soundbox cables (part number 2286) only work with non-ADB monitors and soundboxes.

ADB cables have mini-DIN 4 connectors. ADB NeXT keyboards have a flat green power button. ADB NeXT mice are rounded. Apple Macintosh ADB keyboards and mice should also work. ADB peripherals are only supported on NeXT hardware with ROM version v.74 (most turbo systems and some later non-turbo systems). You also need a newer mono MegaPixel Display (N4000B) or ADB soundbox (serial number prefix ADD). Additionally, you need an ADB monitor cable (part numbers 4534 or 4535) or an ADB soundbox cable (part number 4536).

Black Hole, Inc. has a graphic depicting the differences. ChannelU also has a webpage with pictures of these devices.

How do I run my NeXT headless?

From The Peanut's Archive FAQ. Also, see this post describing how to build a better switch.

The procedure is to just touch pins 6 and GND on the DB-19 NeXT monitor out with a 470 Ohm resistor (450 is the actual resistance, but 470 ohms is more commonly found in resistors). The touching with the resistor will be momentary, you shouldn't try to set up a resistor so that it's always touching.

Pin 6 is the power sense, and pins 13-19 (and the DB shell) are the GND. Just say "pin 19", it may be easier. There's a pinout diagram of the DB-19 in the NeXT Users Reference Manual, as well as below.

If you have an old Cube (serial number below AAK0016370), the power supply needs to have more power drawn from it than an 030 (and 040?) board uses to stay on. So: On the DB-19, attach a Power Resistor (20 Ohm, at least 20 Watt) between pins 12 and GND. (Pin 12 is -12V, pin 13 works well for GND). Then just "momentarily touch" the 470 ohm resistor as described above, and you're set. The 20 Ohm resistor draws enough to keep the power supply happy - just don't touch it (*HOT!* ;-)

To power off, type "halt -p" as root on the machine (either through a terminal connected to port A, or over the ethernet connection).

Also, you need to use the NeXT keyboard to set up the ROM Monitor. The important ones are:

  • Wait until keypress? N
  • Sound out tests? N
  • Port A as alternate Console? Y (if you have one, it's nice)
  • Verbose mode? N (this may need to be N to work)

How do I build a serial console cable?

See the NetBSD Serial Port Primer for more information.

What is the pinout of the monitor cable?

The NeXT monitor cable is a very strange DB19 connector. You won't find any of these outside for special order shops. The cable, as seen from the back of the machine:

        10                  1
      \  o o o o o o o o o o  /
       \  o o o o o o o o o  /
        19                11 
  1. +12V
  2. -12V
  3. MON CLK
  7. NC
  8. VSYNC
  9. HSYNC
  10. VIDEO
  11. +12V
  12. -12V
  13. GND
  14. GND
  15. GND
  16. GND
  17. GND
  18. GND
  19. GND

Other sources of information


(see section 5 on black hardware)

NeXT Hardware FAQs

The wscons documentation

About NetBSD's platform-independent workstation console driver.

Diskless NetBSD HOW-TO

NetBSD Serial Port Primer