Japi Base Editor (JBE)

JBE is the on-device code editor for the Japi Base retro computer platform (Raspberry Pi Pico 2 / RP2350). It feels like the classic Turbo Pascal / QuickBASIC IDEs: a dark-blue full-screen editor, a menu bar at the top, a status line at the bottom and everything reachable from the keyboard.

This is v2.2, a production release. It runs on real Japi Base hardware over VGA + PS/2; the editor, its Japi Commander file manager and the built-in calculator are stable. See Versioning for what the number means.

The hardware

Japi Base is a real machine. In the Japi Base repository you will find how to breadboard or perfboard the required hardware. You will also find the PCB there together with instructions on how to order one from JLCPCB.

How it is developed

JBE is built on Linux against a Japi Base simulator. The simulator implements the same japi_base.h API as the real hardware (VGA text mode of 127 columns × 64 rows, PS/2 keyboard input, file I/O against the LittleFS "flash floppy"), so the editor's source can be developed, run and tested entirely on a desktop machine. The exact same source files compile against the on-Pico implementation of japi_base.h.

This keeps the iteration loop fast (no flashing, no SD shuffling) while guaranteeing that we stay inside the platform's seam — JBE may not touch anything that will not exist on the Pico.

Build and run it yourself

You can run the editor on your own Linux machine in a minute, no hardware needed. All you need is gcc and git.

The quickest way — clone this repo and let the setup script fetch the platform and build + test in one go:

git clone https://github.com/JanFromBelgium/JapiBaseEditor.git
cd JapiBaseEditor
./sim/setup.sh           # clones JapiBase as a sibling, builds, runs the tests
cd sim && ./jbe A:scratch.txt

Or do it by hand — check out the platform next to this repo (the build links against its simulator) and run make:

git clone https://github.com/JanFromBelgium/JapiBase.git
git clone https://github.com/JanFromBelgium/JapiBaseEditor.git
cd JapiBaseEditor/sim
make jbe                 # build the editor on the host simulator
./jbe A:scratch.txt      # open a file (drive letter + path, like on the device)

The folder names matter: the build expects the platform at ../../JapiBase, so keep the two repos named JapiBase and JapiBaseEditor side by side (cloning the URLs above does exactly that).

make demo builds and opens a sample file, make test runs the test suite. The terminal needs to be at least 127×64 characters. See sim/README.md for the details — and if you want to write your own program for Japi Base, the same simulator is how you develop and test it before it ever touches hardware.

On real hardware

To run the editor on a real Raspberry Pi Pico 2, build the standalone firmware (needs the Pico SDK alongside the steps above):

cd japi-base-editor/pico
cmake -G Ninja -B build -DPICO_SDK_PATH=/path/to/pico-sdk .
ninja -C build           # -> build/japi_base_editor.uf2

Hold BOOTSEL, plug in the Pico 2 and copy the .uf2 across. This is the editor-only machine (no BASIC); see pico/README.md. The full Japi Base Computer (editor + BASIC) is a separate firmware.

What it does

• Two open files at once — one per pane of the split-screen view. Edit two files side by side, or two views of the same work.
• File menu — New, Open, Save, Save As, Close, all with an unsaved-changes guard so you never lose work by accident.
• Stream and block selection. A stream selection is the normal kind: it flows from the start point to the cursor across line ends, like selecting a sentence or a run of code. A block (column) selection grabs a rectangle of columns across several lines, regardless of how long each line is. The block mode is what makes column work easy — line up a set of assignments, cut a column of numbers out of a table, or comment a vertical strip.
• Clipboard with stream/block awareness (cut, copy, paste).
• Toggle line comment on the current line or selection.
• Format — a BASIC-aware tidy-up: re-indent, trim trailing spaces and uppercase keywords and built-in functions, over the file or a selection.
• Undo / Redo with word-grain coalescing, multi-line steps and a 32 KB per-buffer history budget.
• Find — incremental, case-insensitive, wrap-around.
• Replace — with per-match Y / N / All confirmation.
• Keystroke macros — record a sequence once, then replay it.
• Syntax highlighting for Z80 assembly and Basic, plus extra schemes loaded from C:config/syntax/ on the device.
• Long-line wrapping with a marker glyph.
• Horizontal split-screen, Turbo-Pascal style — toggle the windowed view, swap focus between panes and move the divider.
• Full CP437 character entry — accented letters, box-drawing glyphs and symbols, so layouts like French AZERTY type correctly.
• Built-in help — a Help menu and F1 open the manual right inside the editor, in a window that floats over your work. F1 in a menu jumps straight to that menu's section, or to the highlighted item.
• Built-in calculator — press NumLock for a calculator over your text: a programmer's calculator (hex/decimal/binary, bitwise, selectable width) and a classic floating-point one, with Shift+Tab to switch and Ctrl+C / Ctrl+V to move a number between the calculator and your code.

Keyboard

Every menu opens with an Alt accelerator and the common actions also have a Ctrl shortcut. Grouped by menu:

File (Alt+F)

Action	Alt	Ctrl
New	Alt+F, N	Ctrl+N
Open	Alt+F, O	Ctrl+O
Save	Alt+F, S	Ctrl+S
Save As	Alt+F, A	—
Close	Alt+F, C	Ctrl+W

Edit (Alt+E)

Action	Alt	Ctrl
Cut	Alt+E, T	Ctrl+X
Copy	Alt+E, C	Ctrl+C
Paste	Alt+E, P	Ctrl+V
Select all	Alt+E, A	Ctrl+A
Toggle comment	Alt+E, G	Ctrl+G
Undo	Alt+E, U	Ctrl+Z
Redo	Alt+E, R	Ctrl+Y

View (Alt+V)

Action	Alt	Ctrl
Toggle windowed view	Alt+V, W	—
Other pane	Alt+V, O	Ctrl+Tab
Move divider up	Alt+V, U	Ctrl+Up
Move divider down	Alt+V, D	Ctrl+Down

Search (Alt+S)

Action	Alt	Ctrl
Find	Alt+S, F	Ctrl+F
Replace	Alt+S, R	Ctrl+R

Macro (Alt+M)

Action	Alt	Ctrl
Record start/stop	Alt+M, R	Ctrl+T
Play	Alt+M, P	Ctrl+P

See JBE_MANUAL.pdf for the full user-facing documentation.

Japi Commander

The editor ships with Japi Commander (Run > Japi Commander, or Ctrl+J), an early two-pane file tool. For now it copies files between the drives — its first job is to copy files from the SD card (A:) onto the built-in flash drive (C:), which is exactly what you need to get programs and config onto the machine. This is a v0: more file operations (move, delete, rename, make-directory) are planned and it is the seed of a small file manager.

A note on Basic

The Japi Base Basic language is a separate work in progress and is not part of this repository. When JBE is later built into the full Japi Base Computer the menu bar gains a Run > Basic Interpreter entry to run the current program, but that interpreter is developed on its own track.

What is coming

• More syntax schemes and editor polish.

Versioning

Japi Base Editor uses the same Linux-style even/odd scheme as the Japi Base platform, on its own version line, so the number tells you whether a release is stable or experimental:

• Even major versions are production releases — stable and ready to use (2.0, 2.2 …). The minor number increments for stable, non-fundamental updates.
• Odd major versions are development releases — work in progress that is not yet production-stable. When it stabilises it graduates to the next even production version.

This is v2.2 — an even, production release. It runs on real hardware and is stable for everyday work, with no known defects. v2.0 was the first production release; v2.1 added the source formatter and full recursive folder operations in the Commander; v2.2 brings the built-in calculator (NumLock) into the editor.

License

Released under the BSD 3-Clause License — see LICENSE for the full text. The same permissive licence as the Japi Base platform, so you are free to use, modify and redistribute the editor.