This is the very first vi version (1.1) taken from 1BSD. It had been released on January 1, 1978.

The software is downloaded with

git clone https://github.com/n-t-roff/ex-1.1.git

and can be kept up-to-date with

git pull

Some configuration (e.g. installation paths) can be done in the makefile. For compiling it on BSD and Linux autoconfiguration is required:

$ ./configure

The software is build with

$ make

and installed with

$ su
# make install
# exit

All generated files are removed with

$ make distclean

While vi version 2.2 behaves quite similar to later versions, vi version 1.1 is rather different (see ex1.1-2.0.pdf). Please study the manual exrefm.pdf carefully. This version does not start in visual mode. There is no -v option. Program names vi and view did not exist. So you have to enter the command vi at the ex prompt :. If the file is empty (or no file is loaded), command vi won't work. In this case you need to issue the a command (append) to type some text. After that you put a . (dot) on a line by itself to quit append mode. With the added text, command vi will work. Note that ex-1.1 places the cursor at the last line of the file. Use 1G or - or k to move upwards. Alternatively use 1vi as first command to open visual at first line. After any command ex-1.1 stays in ex mode. vi will put the current line to top of the window. Use command vi. instead to open visual with the current line centered in the window. The most significant differences are:

• Don't use unescaped @ in input mode, type \@ instead. @ in input mode deletes the current line. This is an intended feature and not a bug.
• Use q (instead of :) to enter an ex command. After that you stay in ex mode. Use command vi to go back to visual mode.
• Only nG, -, k can be used to move upwards. ^B, ^U and ^Y did not exist. (H- can be used instead of ^U.)
• ^F did not exist, use ^D
• Use ^Z instead of ^L. (Job control had been added in version 3.4.)
• Use \\ instead of dd. After deleting lines a @ appears at that position. This is intended and not a bug. (You may ignore these lines or type ^Z to remove them.)
• Use Y instead of yy.
• Note that it is not possible to delete a range of lines with :startline,endlined and then insert these lines with p or P. On change between ex and visual mode the yank buffer information it lost. So even :lineput can't be used. The combination delete/put does only work if ex mode is not left. Alternatively use n\\ to delete and p/P to insert.
• In input mode use ^H instead of <BACKSPACE>
• Use :e` instead of :e# to address the alternate file name. (Also ^^ and ^6 did not exist.)
• Neither ZZ nor :wq nor :x had been implemented. Use the sequence qw<ENTER> q<ENTER> to write and quit. (Can be combined as qw|q.)
• /, ? and n search only for the first occurrence of a pattern in a line.
• Use Kletter instead of mletter to set marks.
• d can only be used for delete operations within a single line. Operations like dG or d1G don't exist before ex version 2. Use ex commands ,$d and 1,d instead.
• Control characters are printed as ? and it is not possible to insert them preceded with ^V. Use at least vi version 2.2 to edit control characters in files. (Existing control characters are left unchanged by vi 1.1.)
• % (find matching (), {} or []) is not available before ex version 2.
• % and ` are substituted for the current and alternate filename only in filenames. Use 1,$ instead of % to address all lines of the current buffer.
• , (intraline search in reverse direction) is not available before ex version 2, but ; exists.
• ]] and [[ (search for begin of a C function, i.e. a line starting with {) had not been available before ex version 2.
• After upward scrolling or using nG some word characters may be displayed as spaces. This is a visual effect and not a data issue. Going to ex mode with q and returning to vi mode fixes this. A single line can fixed with the sequence \\u. (Downward scrolling doesn't have this problem.)
• The code is compiled for editing files with at most 16384 lines and 256 KB temp file size.

Attention: The original vi had not been 8-bit clean! Moreover it does automatically change all 8-bit characters to 7-bit in the whole file even if no editing is done! This will e.g. destroy all UTF-8 characters.