Instruction manual

16
Console
This chapter covers the following topics:
• Console device (Section 16.1)
• Console saved state (Section 16.2)
• Console program (Section 16.3)
• Console commands (Section 16.4)
• Console data structures (Section 16.5)
• Console service routine overview (Section 16.6)
• Console service routine descriptions (Section 16.7)
16.1 Console Device
The console program operates a terminal which may be either the built-in
video/keyboard or an attached terminal connected through the printer port. The
attached terminal may be a video terminal (for example, a VT220), a hardcopy
terminal (for example, an LA34), or a host computer running special software.
Console terminals for the DEC 3000 AXP workstation must support at least
USASCII graphic character encoding. The terminal may optionally support the
DEC Multinational Character Set, which is a superset of USASCII. National
replacement character sets are not supported. Characters normally transmitted
by the Console program are the USASCII graphic characters 21
16
(!) through
7E
16
(~), the space character 20
16
, and control characters 0D
16
(<CR>), 0A
16
(<LF>), and 08
16
(<BS>).
Attached workstation console terminals must support at least USASCII character
encoding. Non-US national replacement character sets are not supported. The
attached terminal is interrogated to see if it supports 8-bit DEC multinational
characters and if it is a CRT or a hardcopy device. This test is made by sending
a Primary Device Attributes Request through the serial port and waiting for an
appropriate Device Attributes Response. The actual characters transmitted are
1B
16
,5C
16
,1B
16
,5B
16
,34
16
,69
16
,1B
16
,5B
16
,63
16
(which is <ESC> \ <ESC>[4i
<ESC> [ c).
The response is compared against those of the most popular Digital terminals
to determine these characteristics. On an absent or unknown response, the
firmware assumes that the device is a hardcopy device with no multinational
character support.
An attached terminal must operate at a rate of 9600 baud for both transmission
and receiving. The serial line parameters must be set for 8 bits, no parity, and 1
stop bit.
Console 16–1