Web implementation appears

README.md

@@ -282,6 +282,15 @@ Reference implementations
   program file name is optional and used for preloading MU8 program files into
   VM's memory. The Busybox AWK implementation is compact but quite slow, so use
   it as a last resort solution when no other programming environment is available. 
+* [Web (HTML5/JS) implementation](https://mu808.luxferre.top) aka mu8web:
+  supports the entire mu808 spec except the I/O port 2 and offers a way to
+  load program files in the same MU8 format via a convenient UI.
+  Uses a convoluted flow to achieve true synchronous input.
+  Since there's no exiting to the OS environment, the -5 instruction number
+  resets the VM instead (by zeroing out both memory areas and the counter).
+  Entry conventions within UI are pretty much the same as for 808UL. Tested
+  on various devices with physical keypads and touch screens. The source code
+  can be found in the [mu8web](mu8web/) directory of this repo.
 
 ### Assembler reference implementations
 
@@ -293,6 +302,29 @@ Reference implementations
 These lists are going to be expanded as soon as new reference implementations
 appear.
 
+### Web reference implementation keyboard controls
+
+The virtual keyboard (unavailable on the smallest screens) is duplicated with
+the following keys at all times in the mu808 Web reference implementation:
+
+* `0`-`9`: decimal digits input;
+* `*` (star), comma, dot: decimal point input;
+* Space, `+`, `/`, down arrow, Call key (if present): whitespace input;
+* Backspace, Delete, left arrow, `-`: minus or backspace input (as the minus sign
+  can only be entered at the beginning of the instruction or data input line);
+* `#` (pound, hash sign), Enter: newline input;
+* `l`, `L`, up arrow, Left Soft key (if present): open a program file loading dialogue.
+
+### 12-key (DTMF) input method proposal
+
+For hobbyist projects and other environments where all input is limited to 12
+keys of the standard phone keypad, the following convention is recommended:
+
+* the `*` (star) key is inputting a minus if this is the first position in 
+  the entry, otherwise it's inputting a decimal point;
+* the `#` (pound) key actually confirms entering a single number field, and
+  all instructions are required to contain exactly five numbers.
+
 FAQ
 ---