Eyes-Free Linux

Linux is the only OS whose console can speak from the kernel itself — no desktop needed, no GUI required, speech from the moment init starts. This chapter covers the eyes-free path: Speakup (the kernel-level screen reader), BRLTTY (the braille daemon), Orca (the graphical one), espeakup (the bridge to software speech), and Slint — the distro that ships it all working. The lineage runs through this wiki's existing cluster — the machine that reads text onscreen descends from the one that read it off paper.

The lineage — the hardware that taught software

The chain this handbook's wiki already documents: the Kurzweil Reading Machine (1976 — the machine that read paper), the Braille 'n Speak (1987 — the notetaker that became a speech synthesizer), and Speakup (1998 — the screen reader that lives in the kernel). The kernel still ships speakup_bns.c — the driver that lets Speakup talk through a forty-year-old Braille 'n Speak. The three articles link by tech, not just theme.

Speakup — the kernel speaks

modprobe speakup_soft        # load it, software synth
speakup_soft.start=1         # or kernel cmdline
espeakup                     # the daemon bridging speakup→espeak

Speakup lives in drivers/accessibility/speakup/ — the kernel synthesizes speech as you navigate the console — from boot, before any userspace exists, all the way to a panic. It drives hardware synths (the DoubleTalk, the DECtalk line, the Braille 'n Speak via bns) or espeakup's software bridge to eSpeak. The speakup keymap: review keys read the screen, the numpad navigates; speakup.synth=soft or =bns selects the voice.

BRLTTY — the braille side

brltty -b auto -x auto       # auto-detect the display
systemctl enable brltty

BRLTTY drives refreshable braille displays — the hardware that turns the console into tactile dots — handling every major display's protocol since 1995. It reads the screen, maps cursor position, handles keyboard input on display keys. Speakup speaks; BRLTTY braills; both make the console fully usable without sight.

The rest of the ecosystem

• Orca — the graphical screen reader — GNOME's eyes-free layer
• espeak-ng / speech-dispatcher — the software synths + the speech service
• Fenrir — the modern modular console reader
• Emacspeak — the speaking Emacs environment — Raman, 1995 — still maintained
• Accessible-Coconut, Vinux, Sonar, TalkingArch — the eyes-free distros — each a distro pre-configured for speech/braille from boot

Slint — the featured accessible distro

Slint is Slackware rebuilt for accessibility — the same system this handbook features, but the installer itself speaks. Slint boots a talking installer, ships Speakup+BRLTTY+Orca working out of the box, and is both the handbook's recommended host and its accessibility answer. Installing Linux blind is a solved problem — Slint solved it.

The eyes-free LFS build

Chapter 2's whole setup is console-only — gdisk, mkfs, tar, configure — nothing needs a GUI. Speakup reads every command's output; configure's checks scroll and are read; make's errors speak. The entire LFS build is achievable eyes-free on a Slint host — the toolchain's text-native design is the accessibility. The only friction: make menuconfig's ncurses UI — navigable via review mode, or replaced by make config/make olddefconfig's line-based alternatives.

The distro landscape — the eyes-free distros

Slint's installer's installer speaks — boot the ISO to a talking menu — a blind user installs blind, from scratch.

The kernel config for accessibility

# make menuconfig — Device Drivers → Accessibility → Speakup
CONFIG_ACCESSIBILITY=y
CONFIG_SPEAKUP=y
CONFIG_SPEAKUP_SYNTH_SOFT=y    # software synth
CONFIG_SPEAKUP_SYNTH_BNS=y     # the Braille 'n Speak driver
CONFIG_SPEAKUP_SYNTH_DTLK=y    # DoubleTalk

Inside an LFS system you configure it yourself — the kernel chapter's menuconfig includes Accessibility → Speakup — a feature most distros bury but LFS lets you build in.

The Speakup keymap — reading by hand

Speakup review keys (the numpad):
  8/2 — prev/next line     4/6 — prev/next word    7/9 — prev/next char
  5 — say current char     . — say line    , — say word
  CapsLock+arrows — review movement   PrintScreen — shut up
  Insert+1-9 — read line by number    Speakup key (CapsLock) + F-keys — controls
  speakup.spkup keybindings — the full map in the kernel docs
  CapsLock+NumLock — cursor tracking toggle

The kernel doc Documentation/accessibility/speakup/spkguide.txt is the full manual — the review mode turns any console output navigable.

The espeakup + speech-dispatcher plumbing

modprobe speakup_soft                 # load the soft synth driver
espeakup                              # bridge daemon — speakup → espeak-ng
# or through speech-dispatcher:
speechd-up                            # speakup → speech-dispatcher → any TTS
spd-say "hello"                       # test speech-dispatcher

The chain: kernel-speakup → /dev/softsynth → espeakup/speechd-up daemon → espeak-ng/speech-dispatcher → audio. echo "text" > /dev/softsynth writes speech directly.

The braille side's full surface

brltty -b xw -d /dev/ttyUSB0 -t text    # driver, device, table
brltty -l debug                         # debug verbosity
brltty.conf — driver/model/device/table/kernel prefs
systemctl enable brltty                 # every boot

BRLTTY knows ~50 display protocols — brltty -l lists drivers; autodetect (-b auto) probes USB/Bluetooth/serial.

The Orca/desktop layer

orca                                  # GNOME's screen reader
orca -s                               # preferences
orca --replace                        # restart it
orca's modifier — Insert — the review key

Orca speaks the graphical desktop — AT-SPI2 carries accessibility info from apps. orca + GTK/Qt apps + Firefox/Chromium covered; a fully speaking desktop is standard GNOME.

The reading workflows — how a screen gets read

Speakup's vocabulary:
  Insert+Keypad combos — the review layer:
    PadEnter = say all       Pad+ = say to-end      Pad. = say screen
    Pad0 = shut up           Pad8 = say line        Pad5 = say word
    Pad2 = say phonetic-word Pad7/9 = prev/next line
    Pad4/6 = prev/next word  Pad1/3 = prev/next char
    Pad* = say current line  Pad/ = find
  CapsLock is the speakup modifier on many layouts.
  echo 'key' > /sys/accessibility/speakup/i18n/… — the runtime controls

/sys/accessibility/speakup/ is the live control plane — echo values to change voice, rate, punctuation, synth: echo 9 > .../rate speeds up; echo soft > .../synth switches to the softsynth.

The espeakup/espeak-ng chain — the voice's plumbing

speakup_soft (kernel) → creates /dev/softsynth → espeakup daemon reads it
→ feeds the text to espeak-ng → espeak-ng synthesizes → ALSA → speakers

speechd-up does the same via speech-dispatcher — the middle layer that
lets brltty + orca + speakup share one synthesizer.

/dev/softsynth is the file-as-voice — write "hello" to it and the daemon speaks it. modprobe speakup_soft start=1 brings it up; the daemon does the translating.

The braille surface — brltty's full surface

brltty                        # autodetect the display
brltty -b fs -d ttyUSB0       # driver + device (fs=FreedomScientific, al=Alva, ht=HandyTech)
brltty -q                     # quiet
brltty -e                     # the current screen as a table
brltty -l debug               # debug log
ls /etc/brltty/               # the config — brltty.conf key tables

-b picks the driver (fs FreedomScientific, al Alva, ht HandyTech, pm Papenmeier, vo Voyager — every major braille-display maker); -d the device; brltty.conf maps keys. BRLTTY's been the display layer since 1995 — its driver list is the braille-hardware catalog.

The console-reading disciplines

• less pages predictably — screen readers read line-by-line; pagers are friends
• --no-pager, | cat defeat auto-paging (git's pager speaks awkwardly)
• TERM matters — dumb vs linux vs xterm changes how readers track output
• Line-oriented tools (grep -n, awk, sed) are naturally readable; full-screen TUIs (ncurses) need review-mode fluency
• stty cols 80 keeps output within a braille display's width

Timeline

See also

• Speakup — the kernel screen reader's own article
• Braille n Speak · Kurzweil Reading Machine — the lineage
• Linux · LFS Kernel and Boot