The 624 packer is a executable packer that got released in 1997 by Kim Holviala. It only supports DOS .com files and was targeted to compress 4kb demoscene intros but offers a decent compression of files from 1 kb to 20 kb size. Uses LZSS (Lempel–Ziv–Storer–Szymanski) compression algorithm The assembly unpacking stub is 127 byte small Fixed length huffmann codes are used to store the length and offset of a match Packed data is stored as a bit stream.
When going back down memory lane about my programming projects the first memory that comes up is developing software under DOS. The simple way of writing programs as .com files allowed for a lot of fun stuff like coding size competitions. Those executable files did not include any header and got executed as code starting from first byte of the file. My favorite production of the old days is this 29 byte small intro that I developed 2001 using assembly language.