Similar to S3M

1 - Unformatted manual page Roff/nroff/troff/groff
10X - Gemini 10x printer graphics file - Bitmap graphics
123 - Lotus123 Data file
12M - Lotus123 Smartmaster file
15U - Printer font with PI font set PageMaker
1ST - Usually README.1ST text
24B - 24bit data Bitmap graphics

View all in File Extensions