VED2 editor - nealcrook/multicomp6809 Wiki

Introduction

VED2 is a small vi-like editor written in C.

The code started out as VED and the source code includes these copyright messages:

Copyright (c) 1982, 1986 by Manx Software Systems Copyright (c) 1982, 1986 by Jim Goodnow II

If anyone objects to my dissemination of this code in modified form, please contact me.

The code was renamed in an attempt to distinguish it after many changes were made to the original.

Neal and Carsten worked on VED2 in 2016; most (all?) of the coding was done by Carsten. It was targeted to run under FLEX on Neal's multicomp6809 FPGA-based board, a derivative of Grant Searle's orginal design. Under FLEX, compilation from source requires the McCosh C compiler. It can also build and run on Linux (useful as a debug platform) where it compiles (using gcc) to a svelte 27Kbyte executable (yes, Kilo-bytes, young people; not Mega-bytes).

The motivation was to create a small editor that would work using ANSI screen control. It is hard-wired for an 25-line 80-column display.

The latest version of VED2 is 1.06.

VED2 includes a help screen; additional documentation is provided in a separate file (appended below)

The multicomp FLEX system disk (see a tour of the FLEX system disk) contains these files:

   VED2.LST       136 sectors -- ??
   VED2.CMD        60 sectors -- the executable command
   VED2.DOC        18 sectors -- everything to know about VED2, including how to rebuild it from source
VED2CHG.DOC         4 sectors -- change history

VED2 source code

The source code is in https://github.com/nealcrook/multicomp6809/blob/master/flex/ved.zip

VED2.DOC

Here is the contents of VED2.DOC. This is the same as the version in ved.zip, but has some updates compared to the version on the multicomp FLEX system disk.

VED2 Screen Editor V1.06

VED2 [-tn] [file]

VED2 is a screen-oriented text editor written in C. It was originally written
by Manx Software Systems/Jim Goodnow II between 1982-1986. This version has
been modified to use ANSI sequences to control a 25-line 80-column terminal.
The source code is included in 'makeved.dsk'. VED2 is not particularly fast
or smart, but it does get the job done.

If VED2 is invoked with a file name, that file will be loaded into the memory
buffer, otherwise it will be empty. VED2 does all its editing in memory and so
is limited in the size of files that it can edit.

In VED2, the memory buffer is never completely empty: there will always be
at least one newline in the buffer.

By default, tab width is the current system value. This can be overridden by
the '-t' option. For example:

VED2 -t8 file.a65

this is useful since C programs work well with a tab size of four, but assembly
language works better with a tab size of eight.

VED2 has a 1000 character limit on the size of a line. If a line is longer than
the width of the screen, it wraps to the next line. If a line starts at the
bottom of the screen, and is too wide to fit, the '@' character is displayed
instead of the line. At the end of the file, all lines of the terminal beyond
the end will consist only of a single '~' on each line.

Commands shown with the prefix '*' take a numeric prefix. The prefix is echoed
on the status line as it is typed. With no prefix, * defaults to 1.

VED2 starts in COMMAND mode. Use the 'i' or 'o' commands to enter INSERT mode
(the status line shows the text '<INSERT>'). Press 'Esc' to return to COMMAND
mode.

ENTERING INSERT MODE

i               Switch to insert mode at current cursor position.
o               Insert a new line below the current line, move the cursor to
                that line and switch to insert mode.

MOVING AROUND THE SCREEN/FILE

return/-        Move to the beginning of the next/previous line.
k/j             Move one line up/down , keep cursor x position.
space or l      Move to the next character of this line.
backspace or h  Move to the previous character of this line.

0/$             Move to the first/last character of this line.
Ctl-F/Ctl-B     Page up/down.
T/M/B           Move to the top/middle/bottom line of the screen.
*g              Move to line * of the file.
/string         Move forward to the next occurrence of 'string'.
n               Repeat the most recent search.
Ctrl-R or z     Redraw the screen, centred on the cursor position.

INSERTING/DELETING LINES AND CHARACTERS

r               Replace the character under the cursor with the next
                character typed.
*x              Delete * characters from the cursor up to but not including
                the newline character.
*dd             Delete * lines starting with the current line.

Deleting the last character on the line (newline character) appends the
following line to the current line.

MOVING TEXT AROUND

These commands make use of a 1000 character yank buffer. The contents of this
buffer are retained across files.

*yy             Yank * lines, starting with the current line, into the yank
                buffer.
*yd             Yank * lines, starting with the current line, into the yank
                buffer and then delete them.
p               Paste the lines in the yank buffer after the current line.
                The yank buffer is not modified.

MISCELLANEOUS
?               Display a help screen.

FILE OPERATIONS

Type ':' to use these file-related commands:

:f              Display info about the current file.
:w file         Write the buffer to the specified file name.
:w              Write the buffer to the last specified file.
:e file         Clear the buffer and read the named file.
:e! file        Clear the buffer and read the named file even if the file is
                modified.
:r file         Read the named file into the buffer.
:q              Quit (exit) the editor.
:q!             Quit the editor even if the file is modified.

VED2 protects against accidental loss of the work being edited: it will not
let you exit or edit another file if the current file has been modified. The
'!' command suffix overrides this behaviour.

VED2 will only edit text files. Binary files will not be edited.

BUILDING VED2 ON LINUX

$ cd linux
$ make

BUILDING VED2 ON FLEX

The source files are on the FLEX virtual disk image  "makeved.dsk".
The build uses the McCosh C compiler. If the compiler is on drive 0
and makeved.dsk is disk 2 then rebuild from within FLEX like this:

+++ASN W=2
+++EXEC MAKEVED

An alternative script "MAKEVEDS" performs a stack-checked build.

If you modify the source code outside of FLEX then you can use
flex_vfs to move the source code onto the makeved.dsk virtual
disk image like this:

flex_vfs: mount 0  makeved.dsk
flex_vfs: delete 0.*.*
INFO 14 files match 0.*.*
flex_vfs: uppercase
FLEX file specifiers will be forced to upper-case
flex_vfs: import 0 flex/*.* xxx=compress
INFO 14 files imported (0 skipped)
flex_vfs: exit