BITTO ビット BITMAP FONT VIEWER

BITTO is a web viewer for retro bitmap fonts, specializing in legacy Japanese computer formats from the 80s and 90s (Sharp X68000, NEC PC-98, FM Towns, DOS/V).

Bitto automatically detects and parses the following binary structures:

• FONTX2 (.FNT, .FON): The standard for DOS/V. Supports both Type 0 (Standard/ANK) and Type 1 (Block/Shift-JIS). Bitto parses the block tables to correctly map sparse Kanji data.
• USKCG16 (.FNT, .FNX): Driver format for the NEC PC-98 (MARU98). Bitto automatically detects the header and handles the unique 2-byte gap interleaved between characters.
• PC-98 BIOS (.ROM): Raw ROM dumps from NEC hardware.
• BFNT: X68000 bitmap font format.
• Raw Binary: Heuristic detection for headerless files.
• Other: A few more obscure formats are moderately supported such as .HFN (for monospaced HP 200LX fonts).

• Shift-JIS Native: You can type full Kanji (e.g., 人) or Half-width Katakana (e.g., ｱ). Bitto converts Unicode to the legacy hex codes the font expects.
• Smart Fallback: If you type English text (Hello) into a pure Kanji font that lacks ASCII characters, Bitto automatically converts your input to Full-width Alphanumeric (Ｈｅｌｌｏ) so the text is visible.

• Loading: You can select from the library of exisiting fonts, load your own folder or simply drag a font file into the webpage to load.
• Click-to-Locate: Click any character in the Live Preview area to instantly jump to that character's location in the Waterfall Map.
• Hide Control Characters: For many bitmap fonts, the first 32 characters are "control" characters not meant to displayed. This options hides them.
• Index: Shifts the character code lookup. Useful for raw ROM dumps that start at specific memory addresses.
• Byte Skip: Manually adjust the file header offset if a font looks aligned but "shifted."
• V-Align: Adjusts the font preview text vertically.
• Gap: Adds empty bytes between characters (required for formats like USKCG).

• Japanese Font Encodings @ unifoundry
• FONTX format info @ el-chan.org
• FONTX2 file converter (FONTCONV.COM) with a great help doc outlines different file formats @ vector.co.jp
• X68000 Fonts and JIS @ vampi.tech
• Izumi Library

The included font files have been gathered from various online sources such archive.org, vector.co.jp and nfggames. If you're the creator of a font listed here and wanted it removed, please let me know.

• Opentype.js: For vector font generation.
• Encoding.js: For Japanese character set conversion.