APPENDIX 3 : USING THE EDT EDITOR ON VAX/VMS

If you are using the sideways ROM version of BBC KERMIT on a model B, or
either version on a B+, B+128 or Master 128, you will be able to use the
EDT screen editor on VAX/VMS mainframes to edit your files. This Appendix
describes how you should set up your job to do this, and how the BBC
Computer's function keys are used to control the editor.

If you are using the RAM version of BBC KERMIT on a model B, which
emulates only a 40 character wide teletype, you will still be able to use
EDT, but only in line mode.

A3.1 SETTING UP THE TERMINAL DETAILS

In order to use the full facilities of the EDT editor you must, of course,
set BBC KERMIT to provide a VT52 terminal emulation. This is the default
setting, but if you have changed the terminal type you can return to VT52
mode with the command

  SET TERMINAL VT52

before you use the CONNECT command to enter terminal mode.

Depending on how the VAX/VMS system has been set up, you may also need to
configure it to know that your terminal is a VT52 and not, for instance, a
VT100. You can see what VMS thinks your terminal is by issuing the DCL
command

  $ SHOW TERMINAL

during a job. If the default terminal type is a VT52, you need take no
further action: EDT will automatically adapt itself to use the correct
screen control commands.

If, though, the default terminal type is not a VT52, you will need to take
some action. You can do one of several things here:

1. If you are connected to your VAX system with a directly connected
permanent line, you could ask your system manager to set the terminal
characteristics that VMS will use. This will be permanent, and once it is
done the default terminal type for that line will be a VT52. This will
not, though, be possible if you are using some sort of network to link you
to the VAX system.

2. Whenever you start a terminal job, you could issue the command

  $ SET TERMINAL/DEVICE=VT52

to tell VMS that you are using a VT52. You must do this before you use 
the EDT editor (or anything else, such as MAIL, that sends screen-control
characters). You could include the command in your LOGIN.COM file to save
you having to remember to issue it every time: however, the terminal type
will then be wrong if you ever use a device that is not a VT52.

3. You could include in your LOGIN.COM file the command

  $ SET TERM/INQUIRE

This will make VMS send an "inquiry sequence" to the terminal when you log
in: BBC KERMIT will then identify itself as a VT52, and VMS will set
itself up accordingly. This is probably the preferable method, since it
will adapt itself automatically whatver device type you use. However,
there are some drawbacks. If you use a device that does not respond  to
the inquiry sequence you will see some rubbish charaters appear, and login
may be slowed down slightly: also, any commands you type while waiting for
the login sequence to complete will be discarded. There is also the
problem that some peculiar terminals (ICL terminals are apparently bad
here) may interpret the inquiry sequence as something else entirely, and
may do something strange or even stop working altogether.

A3.2 EDIT KEYPAD KEYS

As we saw in section 4.4, the models B, B+ and B+128 do not possess keys
corresponding to the VT52 keypad, so BBC KERMIT emulates them using the
red function keys. Section 4.4 specified the actual ESCAPE sequences that
the keys will send to the host computer in VT52 mode: here we shall
consider the use of the keys in terms of the EDT editor. If you have a
Master 128 you will be able to use the keypad keys to send the ESCAPE
sequences.

A3.2.1 Models B, B+ and B+128

These machines do not have keypads, so you will need to use the red
function keys to send the ESCAPE sequences to EDT. Note that some editor
functions are invoked by pressing a sequence of keys: in the list below

	F3

indicates that you should press key F3, and

	SHIFT-F1/F3

indicates that you should press SHIFT-F1 (the GOLD function) then F3.

	BBC key sequence	VT52 keypad key	EDT function

	SHIFT-F1		PF1		GOLD

	SHIFT-F2		PF2		HELP

	SHIFT-F3		PF3		DELETE LINE
	SHIFT-F1/SHIFT-F3	GOLD/PF1	UNDELETE LINE

	SHIFT-F7		PERIOD		SELECT
	SHIFT-F1/SHIFT-F7	GOLD/PERIOD	RESET

	SHIFT-F8		ENTER		ENTER
	SHIFT-F1/SHIFT-F8	GOLD/ENTER	SUBS

	F0			0		LINE
	SHIFT-F1/F0		GOLD/0		OPEN LINE

	F1			1		WORD
	SHIFT-F1/F1		GOLD/1		CHANGE CASE

	F2			2		EOL
	SHIFT-F1/F2		GOLD/2		DELETE EOL

	F3			3		CUT
	SHIFT-F1/F3		GOLD/3		PASTE

	F4			4		ADVANCE
	SHIFT-F1/F4		GOLD/F1		BOTTOM

	F5			5		BACKUP
	SHIFT-F1/F5		GOLD/5		TOP

	F6			6		DELETE CHAR
	SHIFT-F1/F6		GOLD/F6		UNDELETE CHAR

	F7			7		PAGE
	SHIFT-F1/F7		GOLD/7		COMMAND

	F8			8		FIND NEXT
	SHIFT-F1/F8		GOLD/8		FIND

	F9			9		DELETE WORD
	SHIFT-F1/F9		GOLD/9		UNDELETE WORD

	UP			UP		CURSOR-UP
	SHIFT-F1/UP		GOLD/UP		REPLACE

	DOWN			DOWN		CURSOR-DOWN
	SHIFT-F1/DOWN		GOLD/DOWN	SECT

	RIGHT			RIGHT		CURSOR-RIGHT
	SHIFT-F1/RIGHT		GOLD/RIGHT	SPECINS

	LEFT			LEFT		CURSOR-LEFT
	SHIFT-F1/LEFT		GOLD/LEFT	APPEND

A3.3.2 The Master 128

This machine possesses a keypad to the right of the main keyboard, and the
arrangement of these keys closely parallels what you would find on a real
terminal. The key arrangement differs most in that the cursor keys on a
real VT52 are in the keypad area: on the Master they are separate, and the
keypad keys that occupy these positions are not used.

The keypad sends EDT control sequences as follows. If the key diagram
shows two functions, the upper one is selected by pressing the key alone,
and the lower is obtained by first pressing GOLD, then pressing the key.

  ---------------------------------
  !	   !	   !	   !	   !
  ! GOLD  ! HELP  ! DEL L !	   !
  !	   !	   ! UND L !	   !
  !	   !	   !	   !	   !
  ---------------------------------
  !	   !	   !	   !	   !
  ! PAGE  ! FNDNXT! DEL W !	   !
  ! COMND ! FIND  ! UND W !	   !
  !	   !	   !	   !	   !
  ---------------------------------
  !	   !	   !	   !	   !
  !  ADV  ! BACKUP! DEL C !	   !
  ! BOTTOM!  TOP  ! UND C !	   !
  !	   !	   !	   !	   !
  ---------------------------------
  !	   !	   !	   !	   !
  ! WORD  !  EOL  !  CUT  !	   !
  ! C CASE! D EOL ! PASTE !	   !
  !	   !	   !	   !	   !
  ---------------------------------
  !	   !	   !		   !
  ! LINE  ! SELECT!	 ENTER	   !
  ! OPN L ! RESET !	 SUBS	   !
  !	   !	   !		   !
  ---------------------------------

