JavaVCPU

Screenshots

These captures show the current JavaVCPU display and Disk Workshop using a separate sample disk. VM images capture the actual Swing display content at 800 × 800 pixels, without desktop borders. Workshop images show the local browser interface. Captured October 11, 2026.

Boot and command line

BIOS POST JV-DOS shell
BIOS power-on self-test reporting POST OK JV-DOS 1.1 startup banner and command prompt
Normal boot briefly displays POST before entering DOS. Click the display and type a command at A>.
Shell help Programming help
HELP showing shell commands CODEHELP showing JVS syntax and opcodes
HELP lists file, media and system commands. CODEHELP explains source statements and bytecode instructions.
File directory Source editor
DIR showing sample filenames and byte lengths Highlighted arithmetic source in the JV-DOS editor
DIR lists files on the virtual disk. EDIT MATH.JVS; Esc saves and returns to DOS.

See Getting started, JV-DOS and JVS programming.

Documents and media

Document pager Palette image viewer
Document pager displaying WELCOME.TXT Palette image viewer displaying a yellow smile
VIEW WELCOME.TXT; arrows navigate, Esc closes. IMAGE SMILE.IMG; Esc, Enter or Q closes.

PLAY THEME.JMT displays playback status while the synthesized voices play. Esc stops playback. This is a text status view; there is no graphical transport or waveform.

Music playback status with Esc to stop

See JV-DOS and Disk and media formats.

Running programs

JVS source execution COM bytecode execution
RUN MATH.JVS producing 42 and returning to the prompt RUN HELLO.COM printing its greeting
The captured arithmetic source multiplies 6 by 7. The seeded guest executable prints a greeting and returns to DOS.
Built-in display greeting Snowfall animation
DISPLAY_HELLO_CPU drawing its greeting SNOWFALL with a falling pixel and settled snow
Programs.Program.DISPLAY_HELLO_CPU Programs.Program.SNOWFALL; a still frame of the pixel animation.

The built-in graphics demos require selecting their program in the loader; they are not DOS commands. Console-only arithmetic, memory and peripheral demos have no separate display view.

See Example programs and COM programming.

Disk Workshop

Open tools/disk-workshop/index.html locally and select a disk. The directory and file editor share one page.

Directory and text editor

Disk Workshop with sample directory and MATH.JVS source selected

Palette image preview

Disk Workshop with SMILE.IMG hex data and palette preview

Tune composer

Disk Workshop with the short-tune composer expanded

See Tooling and Disk Workshop for importing, applying edits and downloading the updated disk.