Bump version to v1.9.2 with CP437/ANSI-BBS support

Update version references (CMakeLists.txt, About dialog, About Flynn),
CHANGELOG with full v1.9.2 release notes, and README/About Flynn with
ANSI-BBS terminal type, SGR attributes, and expanded glyph coverage.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ecliptik

CHANGELOG.md

@@ -2,6 +2,51 @@
 
 All notable changes to this project will be documented in this file.
 
+## [1.9.2] - 2026-03-10
+
+### Added
+- CP437/ANSI-BBS terminal emulation for bulletin board systems
+  - Full 256-entry CP437 lookup table mapping each byte to ASCII, Mac Roman,
+    or QuickDraw glyph rendering
+  - cp437_mode bypasses UTF-8 decoder for raw byte rendering, essential for
+    BBS art using 0x80-0x9F range (C1 control code collision in UTF-8 mode)
+  - ANSI-BBS terminal type in TTYPE negotiation, settings, preferences menu,
+    and connect dialog — follows BBS community convention (ansi-bbs = CP437)
+- True SGR attribute rendering
+  - Italic (SGR 3) via TextFace(italic)
+  - Strikethrough (SGR 9) via horizontal line at cell mid-height
+  - Dim (SGR 2) halves foreground RGB on color systems
+  - Blink (SGR 5/6) promotes background to bright colors (DOS-style)
+- Bold-to-bright color promotion: SGR 1;30-37m promotes to bright colors
+  (indices 8-15), matching standard ANSI/BBS behavior
+- UTF-8 CP437 fallback for BBSes that send raw CP437 bytes despite
+  xterm-256color TTYPE negotiation
+- 57 new QuickDraw glyph primitives: double-line box drawing, mixed
+  junctions, smileys, Greek/math symbols (160+ total primitives)
+- 18 fractional block element glyphs (U+2581-U+258F, U+2594-U+2595)
+- 60 sextant characters (U+1FB00-U+1FB3B) as 2x3 grid patterns
+- DNS-over-TCP fallback for NAT environments
+- Rendering diagnostic script (`scripts/render-test.sh`)
+
+### Fixed
+- DNS resolution through NAT: Snow's DaynaPORT rewrites UDP source IPs,
+  causing Flynn to reject valid DNS responses. Removed redundant source IP
+  validation (txn_id match already authenticates responses)
+- Backspace sends BS (0x08) instead of DEL (0x7F) for BBS compatibility
+  (Linux telnetd accepts both; BBSes universally expect BS)
+- Bytes 0xF8-0xFF silently dropped by UTF-8 parser — now route to CP437
+- Legacy Computing chars (U+1FB00-U+1FBFF) produced double '??' instead
+  of single '?' (they are single-width, not wide)
+
+### Changed
+- Glyph count: 103 → 160+ QuickDraw primitives
+- Dead code removal: 25 cases from boxdraw_to_dec() superseded by glyph
+  tables, 3 cases from unicode_symbol_to_macroman(), dead block element
+  fallback block (~50 lines, ~700 bytes recovered)
+- Performance: eliminated double cell fetch in draw_row() (~80K cycles/redraw
+  saved on 68000), replaced dark shade MULU with shift operation
+- New source files: `cp437.c`, `cp437.h`
+
 ## [1.9.1] - 2026-03-10
 
 ### Changed

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.9)
-project(Flynn VERSION 1.9.1)
+project(Flynn VERSION 1.9.2)
 
 add_application(Flynn
     src/main.c

README.md

@@ -29,8 +29,10 @@ No build toolchain required — just download and run.
 ## Features
 
 - **Multiple sessions** (up to 4 simultaneous windows)
-- **VT100/VT220/xterm/xterm-256color terminal emulation**
+- **VT100/VT220/xterm/xterm-256color/ANSI-BBS terminal emulation**
+- **CP437/ANSI-BBS mode** for bulletin board systems (full 256-char CP437 rendering)
 - **256-color support** on System 7 with Color QuickDraw (zero System 6 impact)
+- **SGR attributes**: bold, italic, underline, dim, strikethrough, blink, inverse
 - **UTF-8 with box-drawing, Unicode glyphs, emoji, and Braille patterns**
 - **Resizable window and scrollback** (80x24 up to 132x50)
 - **6 fonts** (Monaco 9/12, Courier 10, Chicago 12, Geneva 9/10)

docs/About Flynn

@@ -1,7 +1,7 @@
 =====================================================
                       Flynn
               Telnet Client for Macintosh
-                    Version 1.9.1
+                    Version 1.9.2
 =====================================================
 
 Connect your classic Macintosh to the modern world.
@@ -25,6 +25,13 @@ handles UTF-8 text, and provides all the keyboard
 mappings needed to work comfortably on the original
 Macintosh keyboard.
 
+Flynn also supports CP437/ANSI-BBS mode for connecting
+to bulletin board systems (BBSes). The ANSI-BBS
+terminal type enables raw CP437 byte rendering for
+correct display of BBS ANSI art, including block
+elements, shade characters, and the full CP437
+character set.
+
 On System 7 with Color QuickDraw, Flynn supports full
 256-color rendering (16 ANSI + 216 color cube + 24
 grayscale). Truecolor sequences are downgraded to the
@@ -86,10 +93,19 @@ Features
     quotes, em dashes, and other Unicode symbols
   - 256-color support on System 7 with Color QuickDraw
     (automatic detection, zero impact on System 6)
-  - Unicode glyph rendering: 103 QuickDraw primitives
+  - CP437/ANSI-BBS mode for bulletin board systems
+    (full 256-character CP437 rendering, sextant and
+    fractional block characters for BBS ANSI art)
+  - True SGR attributes: italic, strikethrough, dim,
+    and blink (DOS-style bright background on color)
+  - Bold-to-bright color promotion for standard
+    ANSI/BBS color rendering
+  - Unicode glyph rendering: 160+ QuickDraw primitives
     (arrows, shapes, blocks, triangles, diamonds,
-    circles, superscripts, subscripts, card suits),
-    15 monochrome bitmap emoji, and braille patterns
+    circles, superscripts, subscripts, card suits,
+    double-line box drawing, sextants, fractional
+    blocks), 15 monochrome bitmap emoji, and braille
+    patterns
   - Alternate screen buffer for full-screen apps
     (vi, nano, less, tmux)
   - 96-line scrollback buffer with position indicator
@@ -104,7 +120,8 @@ Features
   - Six font choices: Monaco 9, Monaco 12, Courier
     10, Chicago 12, Geneva 9, Geneva 10
   - Per-session font and terminal type overrides
-  - Terminal type: xterm, VT220, VT100, xterm-256color
+  - Terminal type: xterm, VT220, VT100, xterm-256color,
+    ANSI-BBS
   - Dark mode (white text on black background)
   - Custom DNS server configuration
   - Username auto-login
@@ -324,9 +341,11 @@ terminal type, networking, and display mode.
   Terminal Type
   ~~~~~~~~~~~~~
   Choose the terminal type reported to the server:
-  xterm (default), VT220, VT100, or xterm-256color.
-  This controls which escape sequences the server
-  sends. Changes take effect on the next connection.
+  xterm (default), VT220, VT100, xterm-256color, or
+  ANSI-BBS. The first four use UTF-8 text encoding;
+  ANSI-BBS uses raw CP437 byte encoding for correct
+  BBS ANSI art rendering. Changes take effect on the
+  next connection.
 
   Networking
   ~~~~~~~~~~

resources/telnet.r

@@ -181,7 +181,7 @@ resource 'DITL' (130, "About Flynn") {
 
 		/* 3: App name + version */
 		{10, 55, 30, 280},
-		StaticText { disabled, "Flynn 1.9.1" };
+		StaticText { disabled, "Flynn 1.9.2" };
 
 		/* 4: Machine type (set at runtime) */
 		{33, 55, 49, 280},