Tap2Dsk is the simpler way of making your program run on floppy disk instead of tape.

The usage is relatively simple, you basically specify a list of tape files, and the destination disk image file, with eventually some parameters for the "init" string.


Tap2Dsk is one of the oldest tools in the OSDK, and as a result was never updated to handle the most commonly used DSK format, so in order to load the generated DSK you will normally have to run it through the Old2Mfm tool.


To create a DSK file using Tap2Dsk, here is the syntax:

	%OSDK%\bin\tap2dsk [switches] tap_file [additional tap files] dsk_file
	%OSDK%\bin\old2mfm dsk_file

Tap2Dsk switches can be:

	-i[Sedoric Init string] contains a command running at boot time
	-c[paper_color]:[ink_color] is supposed to change the color of the name
	-n[disk_label] can be used to change the name of the disk when doing DIR

For example if you have added MYGAME.TAP to your DSK, you can add:


to automatically clear the screen and run the program MYGAME.

Please refer to the Sedoric user manual for a full list of all commands you can use there.

When using the OSDK, you can use OSDKINITST and OSDKDISK to set the initialization sequence and final name of the program


An alternative to Tap2Dsk is FloppyBuilder.

FloppyBuilder is much more difficult to learn, but it provides some benefits over Tap2Dsk:

  • You get access to pretty much the entire top 16 kilobytes of ram while still being able to load from disk
  • Files can be compressed on disk and decompress on the fly, giving you almost twice the amount of data on one single floppy

Known issues

Reported by Hialmar the Sun 3rd June 2018

Issue #23: Generated floppies have no free disk space
Details: Tap2Dsk generates floppies that only contain the provide files, without any spare space, that makes it unpractical to generate floppies for games or tools since you can't save any new file.

Reported by Hialmar the Thu 19th February 2015

Issue #1: Corrupted DSK files
Details: I have no idea why but if you copy files, edit files and the like you end up with corrupted files on the .dsk.

Resolved issues

Reported by Chema the Fri 20th February 2015
Fixed in OSDK 1.7

Issue #2: Missing INIST and DiskName options
Details: Fabrice's version has two options, -i and -n, that can be used to set the INIST startup string and the name of the disk. The version of the OSDK does not have these options.The issue is actually that MAKE.BAT does not pass the parameters: Replacing the call to Tap2DSk by '%OSDK%\bin\tap2dsk.exe -n%OSDKDNAME% -i%OSDKINIST% %OSDKDISK% build\%OSDKNAME%.tap build\%OSDKNAME%.dsk' fixes the issue.

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Coverity Scan Build Status
Version 2.1.1
  • Added a fix to avoid the tool to stay stuck on tapes with incorrect size specified in their headers
Version 2.1.0
  • Upgraded the version of Sedoric 3 used by Tap2DSK with the patch that improves the handling of the "insert master disk" prompt