JV DOS

JV-DOS 1.1

JV-DOS runs as guest bytecode. It provides a shell, persistent named files, an editor, JVS interpretation, COM loading and small media viewers. Commands and filenames should be uppercase. Click the VM window before typing.

Command help (HELP)	Directory (DIR)

Command	Purpose / example
HELP, CODEHELP	Shell or programming help
DIR	List filenames and byte lengths
TYPE NAME, CAT NAME	Print file contents directly
VIEW NAME, MORE NAME	Read a document with navigation
WRITE NAME TEXT	Create or replace text
APPEND NAME TEXT	Append text to an existing file
EDIT NAME	Create/open a file in the editor
COPY OLD NEW	Copy to a new name
REN OLD NEW	Rename to an unused name
DEL NAME, ERASE NAME	Delete a file
SAVE NAME HEX	Create binary content from uppercase hex byte pairs
RUN NAME	Interpret text, load bytecode, or open image/music by type
IMAGE NAME, SHOW NAME	Display a palette image
PLAY NAME	Play a MIDI-note stream
PRINT TEXT, ECHO TEXT	Print literal text
CLS, CLEAR	Clear display
VER, MEM	Version and memory/file limits
SOUND ON, SOUND OFF	Enable/disable keyboard clicks
BEEP	Short tone
REBOOT	Restart the resident guest boot routine
EXIT	Halt the CPU

Files occupy 16 slots, have names of up to 12 characters, and contain at most 240 bytes. There are no folders or large-file allocation chains. The CLI and source reader have a 100-character line limit; use Workshop to import longer documents or binary files. COPY/REN report DESTINATION EXISTS if the target name is taken.

Editor and viewers

EDIT DEMO.JVS opens the guest source editor. Arrow keys move; Home/End navigate the line; Backspace and Delete remove characters; Enter inserts a newline; Tab indents. Esc saves and leaves. It is not a cancel operation. The editor highlights source text.

The document pager uses Up/Down, Page Up/Page Down, Space/Enter and Home; Esc closes it. Image viewing closes with Esc, Enter or Q. Esc stops music and silences its voices. A running JVS program checks for Esc between statements.

Source editor	Document pager

Palette image	Music playback status

The screenshot gallery also shows startup, programming help and program execution.

RUN dispatches image/music from their file type, interprets type-1 text, and otherwise validates and loads raw bytecode. It also heuristically treats binary content starting with printable bytes 32-90 as source. The supplied COM starts with opcode 2 to avoid that ambiguity. Filename extensions alone do not define the execution format.

See JVS programming, COM programming, and Tooling and Disk Workshop.