HP 100LX/200LX icon

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File Format
Name HP 100LX/200LX icon
Extension(s) .icn, .xbg
Released ~1993

The HP 100LX and HP 200LX palmtop computers used a custom icon format, with filename extension .ICN.



We did not find much documentation about this format, but the examples we've seen use a simple uncompressed bi-level format, with an 8-byte header. The image dimensions are stored in the header, but they are probably always 44×32.


A file begins with bytes 01 00 01 00.

Assuming dimensions of 44×32 pixels, the next four bytes are 2C 00 20 00, and the file is exactly 200 bytes in size.

Format details

[This information is based on analysis of a small number of files, and may be incorrect.]

Multi-byte integers are little-endian.

Offset Length Field Observed values Details
0 4  ? hex: 10 00 10 00
4 2 width usually 44 Image width in pixels
6 2 height usually 32 Image height in pixels
8 image_data Pixels are in left-to-right, top-to-bottom order. 8 pixels per byte, most significant bit first, white is 0. Rows are padded to the next byte boundary.


Sample files


Editors' notes

The packages at the "Themes for the X-Finder GUI" site listed above also contain some .XBG files, which use the same format as .ICN, but are larger in image size, and are intended to be used as wallpaper/background images instead of icons. We haven't found any other information about XBG files, but this suggests that ICN may just be a subformat of some other format.

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