How to unzip a zip4 (zipdisk) with DirMaster

Recently, a user asked why they needed to rename files in a zip4 set in order to open them in DirMaster. The short answer is, you don't - as long as they have the standard 1! style prefix. Another user asked what the best way to open a zip4 archive is. We'll illustrate this with a short video showing a situation where you have a four-part zip4 set and you'd like to unarchive and open that:

DirMaster is a Windows-based GUI application designed to help Commodore enthusiasts explore and manage their disk image collections. DirMaster supports common (and uncommon) emulator disk image formats (such as .d64, .d81, .d2m, etc), almost every native Commodore archival format (such as .arc, .sda, .lnx, etc), and many native graphic formats (such as koala, doodle, amica, etc). DirMaster was designed to give users a perfect blend of familiar appearance (e.g. natural looking disk image contents using the PETSCII character set) and modern GUI functionality (e.g. drag and drop, opening multiple disk images at once). The first version of DirMaster was released in 2006.


  • disk image support: .d64, .d71, .d81, .d80, .d82, .d1m, .d2m, .d4m, .dhd, .hdd (read only), .dnp, .dfi, .m2i (read only), .t64, .g64 (read only), .nib (read only)
  • file support: .prg/.p00, .seq/.s00, .usr/.u00, .rel/.r00
  • archive support: .arc, .sda, .lnx, .sfx, .ark, .lbr, .spy, .cvt, .wr3, zip/4 (1!..., 2!..., etc)
  • Windows Explorer integration:
    • file associations/icons
    • file preview panel
    • right click to extract image/.archive contents
  • all the usual directory editing capabilities like sorting, block size change/correction, file type change, lock, splat, etc...
  • most functions activated by keyboard equivalents, including file reordering and filename editing
  • multi-level undo
  • pervasive drag and drop:
    • copy one or more files from one image to another
    • copy files between different image formats (e.g. d64 to d81, dfi to d71, etc)
    • move/reorder files on the same disk by dragging them
    • drag and drop files from disk images to the OS file system
    • drag and drop files from the file system onto disk images
  • multiselection with shift+click & ctrl+click; many operations will work on the entire selection
  • invoke your favorite emulator or other external application (up to eight slots) from within DirMaster to run/process a file or disk
  • sub directory and partition support for relevant formats (d81, d1m, d2m, d4m, dnp)
  • save disk images as a .txt, .csv (with optional MD5 hash per file), .bmp, .png, .rtf. and .html
  • visual BAM mode with track/sector view/edit (hex and PETSCII)
  • support for the most common error and extended disk extensions
  • decompress archives directly from open disk images with one key click
  • support for GEOS file types (new: GeoPaint/GeoPhotoAlbum viewers, GeoWrite to seq conversion)
  • built in viewers for Commodore file types including raw binary (disassembly and hex viewers), SEQ files, REL files, BASIC listings (v2.0 and v7.0), character sets, and many popular image formats
  • recursive find: search your disk image collection with * and ? wildcards; save results to a file
  • batch processing: recursively create .txt, .csv, .bmp, .png, .rtf. and .html or extract to prg/seq files
  • batch processing: send extracted files to an external script/executable
  • experimental OpenCBM support
  • print directory listings for disk envelopes; two sided directory printing
  • maintain your own favorite 'separators': drag and drop them onto your disk image
  • disk forensics:
    • check for cross links
    • list the sector chain for each file, as well as a list of free chains (potentially recoverable deleted files)
    • compare two disks at a sector by sector level
  • customizable palettes; defaults to the "Pepto" palette but can use any .vpl (VICE) format palette file