Sergio's Nexus
 Zip  UnZip
 FSCK  PPPdriver
 RealCount  HSC


I wrote and I used to maintain the official port of the Zip and Unzip programs from Info-ZIP for Acorn RISC OS.

Due to the always decreasing spare time, the stability of the code and mainly due to a lack of interest, I stopped working actively on this project. However, there are other people working to improve the platform-independent code and someone also added some RISC OS specific features.

I don't exclude the possibility to get back into the project if there will be some new exciting development...

This is taken from Zip and Unzip documentation:

Zip 2.2 is a compression and file packaging utility.  It is compatible with
PKZIP 2.04g (Phil Katz ZIP) for MSDOS systems.  There is a companion to zip
called unzip (of course) which you should be able to find the same place
you got zip. See the file 'Where' for details on ftp sites and mail

This version of zip has been ported to a wide array of Unix and other
mainframes, minis, and micros including VMS, OS/2, Minix, MSDOS, Windows NT,
Atari, Amiga, RISC OS, BeOS and VM/CMS. Although highly compatible with
PKware's PKZIP and PKUNZIP utilities of MSDOS fame, our primary objective has
been one of portability and other-than-MSDOS functionality.  Features not
found in the PKWare version include creation of zip files in a pipe or on a
device, VMS, RISC OS, BeOS and OS/2 extended file attributes, conversion from
Unix to MSDOS text file format; and, of course, the ability to run on most of
your favorite operating systems.  And it's free.

UnZip is an extraction utility for archives compressed in .zip format (also
called "zipfiles").  Although highly compatible both with PKWARE's PKZIP
and PKUNZIP utilities for MS-DOS and with Info-ZIP's own Zip program, our
primary objectives have been portability and non-MSDOS functionality.

This version of UnZip has been ported to a stupendous array of hardware--
from micros to supercomputers--and operating systems:  Unix (many flavors),
VMS, OS/2 (including DLL version), Windows NT and Windows 95 (including DLL
version), Windows CE (GUI version), Windows 3.x (including DLL version),
MS-DOS, AmigaDOS, Atari TOS, Acorn RISC OS, BeOS, Macintosh (GUI version),
SMS/QDOS, MVS, VM/CMS, Human68k (mostly), AOS/VS (partly) and TOPS-20 (partly).
UnZip features not found in PKUNZIP include source code; default extraction
of directory trees (with a switch to defeat this, rather than the reverse);
OS/2, VMS, Unix, RISC OS, Macintosh and BeOS extended file attributes; and,
of course, the ability to run under most of your favorite operating systems.
Plus, it's free. :-)

The RISC OS port is just a plain port (ie. it is command line based as the original, no fancy frontend) but has been fine-tuned to work in the RISC OS environment (eg. full filetype support and extension swapping). The zipfiles produced by RISC OS Zip are fully compatible with SparkFS (ie. they retain filetypes and attributes).

The RISC OS port has been released in April 1995 as a beta release (with no sources publicly distributed). On April 1996 new versions of Zip (2.1) and Unzip (5.2) have been released and the RISC OS specific sources has been finally included in the main source tree.


The official distribution site for Info-ZIP is but there are also various other sites/mirrors including and
From here you can download the sources and compile them yourself (the sources have been tested only with Acorn C V5 Compiler but may also compile with Acorn C V4 and Acorn Assembler V2).

The RISC OS executables archives can be found at
and at Hensa (d076).

If you want to have more informations about Zip, Unzip and the Info-ZIP group you should check the Info-ZIP FAQ or the Info-ZIP Page.

© Sergio Monesi
Updated: 29 Aug 1999