INTRODUCTION
D|I|G|I|T|A|L 's VAX 8200 (introduced January 1986, code named "Scorpio") is the successor to the widely installed and highly regarded VAX-ll/780. Providing the same power as its predecessor, the VAX 8200 is intended as a department-level processor in office automation, commercial, and manufacturing applications. The four new models (VAX 8200, 8300, 8500, and 8800) employ a new bus technology that promised to be a D|I|G|I|T|A|L standard for the next decade. The VAX Bus Interconnect (VAXBI), a 32-bit synchronous bus, serves as a combination system and I/O bus on the VAX 8200 and 8300, and as the I/O bus only on the 8500 and 8800. The last two systems employ a high-speed memory interconnect as a system bus. The VAXBI features a maximum data transfer rate of 13.3MB per second and provides connection for up to 16 VAXBI nodes. A VAXBI node is an interface that occupies one of 16 logical locations on a VAXBI bus; it can be a mix of processors, memories, and adapters. Mass storage, bus, and communications adapters are supported.
However, the VAX 8200 also supports the UNIBUS, so the UNIBUS peripherals used by older VAX machines are supported. United by the VAX/VMS operating system, the VAX 8xx0s can be used as standalone processors or can be configured in multi-node VAXclusters for enhanced power, mass storage, and availability. There is one exception: the VAX8500 is is completely VAXBI based, thus no UNIBUS peripherals can be connected.

The relative speed of VAX systems is defined by the comparison of the speed of the VAX-11/780. The speed of the VAX-11/780 is defined as 1 VUP (Virtual Unit of Processing). Using this speed performance unity, the VAX 8200 is also 1 VUP. So, it is not faster, not slower, but it is contained in a significantly smaller housing.
The VAX 8200 is the low end of the VAX 8000 family, which delivers VAX-ll/780 performance in one third the size at half the price. According to D|I|G|I|T|A|L, the VAX 8200 complements the company's Micro VAX II, providing users with expansion capabilities and features not available on that supermicro. The VAX 8200's CPU is similar in design to that of the VAX-11/780, but is available on one 9-inch by 8-inch module, compared to 24 modules on the 11/780.
The VAX 8200 is upgradable to the 8300. The VAX 8300 uses the same technologies as the VAX 8200, but delivers higher performance in compute-intensive applications by using tightly coupled dual 8200 processors. Each CPU contains an 8KB cache memory; main memory is shared through the VAXBI bus. According to D|I|G|I|T|A|L, the 8300 provides up to l.9 times the power (2 MIPS) of the VAX 8200 or VAX-ll/780, thus 1.9 VUP.

• Console terminal (printer)
• Control panel
• Console diskette drive (RX50)
• Console command language

• 4-position keylock switch (upper)
• 3-position keylock switch (lower)
• 3 processor indicator lights
• Restart push button

Upper keylock switch

This switch has four positions. Use it to turn power on and off.

• Off
  The upper keylock switch is set in the vertical position; there is no corresponding light. Turns off the power in the entire system, including the battery backup unit.
• Standby
  When the upper keylock switch is set to Standby, the corresponding indicator light glows red. Turns on the power supply, the blower in the main unit, and system memory.
• Enable
  When the switch setting is changed from Standby to Enable, the system self-tests run. When the upper keylock switch is set to Enable, the corresponding indicator light glows yellow. Power is supplied to the entire system. You can use the local console terminal in console mode to control the computer. If the lower keylock switch is set to Auto Start, pressing the Restart push button reboots the system.
• Secure
  When the upper keylock switch is set to Secure, the corresponding indicator light glows green. This setting maintains power to the entire system and is used for normal operation. You cannot use the local console terminal in console mode to control the processor. You cannot reboot the operating system by pressing the Restart push button.

Lower keylock switch

This switch has three positions. Use it to enable and disable automatic restart after a power failure.

• Update
  When the lower keylock switch is set to Update, the corresponding indicator light glows red. You can change data in the Electrically Erasable Programmable Read-Only Memory (EEPROM) using the EEPROM Utility.
• Halt
  When the lower keylock switch is set to Halt, the corresponding indicator light glows yellow. The system halts in console mode. It displays the console-mode prompt (>>>) at the console terminal when power is turned on after a power failure, after an error halt, or after a shutdown. This setting prevents booting of the operating system when power is turned on.
• Auto Start
  When the lower keylock switch is set to Auto Start, the corresponding indicator light glows green. Use this setting for normal system operation to let the system reboot automatically when power is restored after a power failure, after an error halt, or after a shutdown. If the upper keylock switch is set to Enable, pressing the Restart push button reboots the system.

Indicator lights

• Run
  Glows when the processor is running and the console subsystem is in program mode.
• Battery
  Shows the condition of the backup battery.
  • Steady glow     - The backup battery is fully charged.
  • Slow flashing   - The backup battery is charging itself.
  • Quick flashing - The backup battery is supplying power to the system.
  • No light            - The backup battery unit is broken or is not present.
• Fault
  Glows during self-tests and turns off when self-tests complete successfully. If the Fault light continues to glow after self-tests complete, the self-tests have detected a hardware fault. If the Fault light glows after self-tests complete and the VMS operating system boots, the system has detected a failure in a hardware module.

Restart Push Button

The Restart push button is located on the lower right side of the control panel. The table details the functions of the Restart push button, which depend on the positions of the upper and lower keylock switches.

Upper keylock switch setting	Lower keylock switch setting	Restart button function
Enable	Auto Start	Runs self-test and reboots the VMS operating system
Enable	Update or Halt	Runs self-test
Stand by or Secure	Any position	Does not function

 

• Install updates
• Install optional software products
• Boot standalone BACKUP
• Store boot command procedures

• The light below the drive flashes when the floppy diskette is actually moving (being read or written to). If this light is off, the drive is inactive. Never attempt to remove a floppy diskette when the light is flashing or glowing; this damages the floppy diskette and might damage the drive.
• The light is off when the drive is empty. The only time you can remove a floppy diskette is when the light is off.

1. Make sure the diskette drive is inactive. The light below the drive should be off. Never attempt to open the diskette drive door if the light is glowing or flashing.
2. Press the outer portion of the right door to open console diskette drive CSA2.
3. If there is a diskette in the drive, remove it gently, taking care not to touch any exposed platter surfaces. Place the diskette in a paper envelope.
4. Remove the diskette to be inserted from its paper envelope; do not touch any exposed platter surfaces.
5. Align the orange arrow on the diskette with the orange bar on the drive. Slide the diskette into the left-hand side of the drive. (If the diskette is aligned improperly, the system displays an error message. If the system displays an error message, remove the diskette, realign it, and reinsert it.)
6. Close the diskette drive door.

Console command language
The console subsystem runs in two different modes: console mode and program mode.

• Console mode — When the console subsystem is in console mode, the VMS operating system is not running and the console-mode prompt (>>>) is displayed. The CPU can be running or it can be stopped. When the CPU is running, it responds to a limited number of commands. When the CPU is stopped, it responds to all console-mode commands. To stop the CPU, press Ctrl/P at the console-mode prompt (>>>).
• Program mode — When the console subsystem is in program mode, the VMS operating system is running and the dollar sign prompt ( $ ) is displayed. You can enter DCL commands, run programs, and receive system messages. If the VMS operating system is running and you want to go to console mode, follow the shutdown procedure. You also can press Ctrl/P to suspend program mode temporarily and go to console mode. To get back to program mode, enter the CONTINUE command at the console-mode prompt (>>>).

See  https://bitsavers.org/pdf/dec/vax/8200/