P-Screen COM Screen
P-Screen COM Screen is a character graphics format native to P-Screen, a DOS utility developed by Rob W. Smetana and Pro-Formance. It is a self-displaying COM file. The format was introduced in P-Screen v3.1.
It is essentially a variant of TheDraw COM File. But it is a different format, not compatible with any version of TheDraw COM File.
As of v5.5, the freely-distributable version of P-Screen can read the format, but does not support writing it.
Contents |
Format details
[This section contains unverified information. It was written for the fileformats.archiveteam.org wiki.]
Compression
The payload data is compressed with a simple RLE scheme.
To decompress: Read bytes in pairs (foreground + attributes). Any pair other than 1a 00 is normal uncompressed data.
If the pair is 1a 00, then read 4 more bytes. The first of these bytes is a repeat count. The second seems to always be 0 (maybe the high byte of the repeat count, but it seems that repeat counts can't be larger than the screen width). The last two are the foreground and attributes bytes to repeat.
Identification
Files start with bytes eb 3d, and have ASCII text at offset 9 that begins "Pro~Formance Screen Design".
More robust identification is possible, though probably unnecessary. See TheDraw COM File#Identification for more information.
Software
- P-Screen v3.1: Resource For Source BASIC → BASIC_01/PSCRN31.ZIP
- P-Screen v5.5
- Deark
Sample files
- SPARKL41.ZIP → *.COM
- PSCRN55.ZIP → PSCREEN.COM
