📖 User Manual — the full guide, written in period style (and in markdown, naturally).
A markdown-first text editor for the Apple ][+ (48K + Language Card), written in 6502 assembly, cross-developed with cc65 and tested in Virtual ][ before going to real hardware via ADTPro.
The Apple ][ can't render font effects, so texr instead treats markdown
syntax as a first-class citizen: files are plain markdown, ready for
any modern renderer, and the editor actively assists with the syntax.
First such feature: typing --- or === at the start of an empty line
auto-fills the rule to the right margin and advances to the next line.
Documents live in a 99-line buffer ($4000); the 23 text rows are a
scrolling window into it, so files can be four screens tall. See
milestones.md for what's shipped and what's planned.
ESC help popup (ESC again closes; ctrl-? also opens on a //e)
RETURN splits the line at the cursor (at column 0 this
inserts a blank line above). On a "- " / "* " list
item the next line auto-starts with the same marker,
and RETURN on an empty item removes the marker and
ends the list
left/right move cursor
^J / ^K cursor down / up (also //e up/down arrows)
^N toggle the line-number gutter (display-only: the
last 3 columns of each line are hidden while it's on)
^D backspace: delete char left of cursor, pull line left.
At column 0 the line joins onto the end of the
previous one (refused if the two don't fit in 40
columns). On a pristine (untouched) document, ^D
instead loads a bundled demo showcasing every
markdown feature. Pressing ^D to dismiss the splash
screen goes straight into the editor with the demo
already loaded — no need to dismiss the splash first
^P hi-res preview: renders the document at 280x192 with a
5x7 software font (ESC returns to the editor).
Markdown is rendered, not echoed:
- "- " / "* " items get an indented round bullet dot
- "---" becomes a solid pixel rule, "===" a double rule
- "# " headings drop their markers, are underlined, and
get a blank row above and below to set them off;
h1 ("# ") is also rendered bold by double-striking
each glyph one pixel apart
^S save as a plain DOS 3.3 text file (readable markdown
on disk): filename prompt on the status row, RETURN
accepts, ESC cancels. ".MD" is appended automatically
so texr can recognize its own documents
^O file picker: lists the ".MD" text files on a drive
(read straight from the DOS catalog with RWTS) in a
modal box. ^J/^K or arrows move the highlight, RETURN
loads, 1 / 2 switch drives (data disk in drive 2 is
the default), ESC cancels. Disk errors show
"DISK ERROR n" and return to the editor
^Q quit: reboots the disk (after file I/O, DOS 3.3
cannot survive a BRUN program returning, so texr
restarts like most period application disks)
printables insert (shifts the rest of the line right)
MANUAL.md the user manual (period style)
milestones.md shipped and planned feature log
bin/bootstrap.sh check toolchain; offers to install what's missing
bin/build.sh assemble src/ and produce a bootable build/texr.dsk
bin/build_and_run.sh build, then (re)boot the disk in Virtual ][;
also creates disks/data.dsk (once) and keeps
it attached to drive 2 for ^S/^O
bin/screen.sh print the emulator's text screen to stdout
bin/snap.sh [out] save a PNG screenshot of the emulator screen
bin/demos/ feature demos: markdown_render_demo.sh builds,
boots, types a showcase document, and ends on
the ^P hi-res render. _wait_for_ready.sh polls
the emulator's screen text every 0.5s (rather
than sleeping a fixed guess) for the boot
banner, dismisses it, then waits for the
editor's status bar before a demo starts typing
src/main.s entry point + shared routines (ca65 syntax)
src/defs.inc constants, zero-page map, text macros
src/banner.s splash screen
src/editor.s editor main loop
src/hgr.s hi-res preview renderer (7x8 cells, 40x24)
src/font.s 5x7 font as editable # art, ASCII $20-$5F
src/demo.s bundled demo document, loaded by ^D on an
empty document (see splash screen hint)
src/disk.s ^S/^O DOS 3.3 text-file save/load, with a
patch-trap on DOS's error handler
src/catalog.s ^O file picker: RWTS catalog scan + modal
selection UI
disks/template.dsk bootable DOS 3.3 template (copied from System Master)
disks/data.dsk persistent blank data disk in drive 2; never
overwritten by builds, so saved docs survive
tools/ AppleCommander CLI jar (downloaded by bootstrap)
build/ outputs: texr.bin, texr.lst, texr.dsk
bin/bootstrap.sh # once, or whenever tools change
bin/build_and_run.sh # edit -> build -> boot loop
The generated build/texr.dsk boots DOS 3.3 and its HELLO greeting does
BRUN TEXR, so the program runs automatically at power-on. The same image
can be transferred to a real floppy with ADTPro.
Note: bin/build.sh recreates build/texr.dsk from the template, so
save documents to the drive-2 data disk instead: give ^S a filename
like NOTES,D2. DOS remembers the drive, so later plain names keep
using drive 2 until a ,D1 switches back. disks/data.dsk is created
once and never touched by builds — documents there survive rebuilds,
and the image can go to a real floppy with ADTPro.
- Program ORG is
$6000(set inbin/build.sh), safely below DOS 3.3 at$9600. - The document buffer sits at
$4000-$4F77: 99 fixed 40-byte line records of screen codes. The text page is only a view of it. - Text page 1 lives at
$0400-$07FFwith interleaved rows:base = $400 + (row mod 8) * $80 + (row div 8) * $28. - The Language Card gives 16K of bank-switched RAM at
$D000-$FFFF(soft switches$C080-$C08F) — future home for 400+ line documents.