JaffyDOS is a custom kernal for the C64/SX64 with enhancements for SD2IEC.
Filebrowser and Kernal modifications by: jani@worldofjani.com

2017-07. Version 1.2 (Recommended)
* Includes saveroutine fix from v1.1.
* Filecopy works again with files up to 201 blocks.
2017-07. Version 1.1 (Obsolete. Don’t use)
* Quickfix for those who experienced problems.
* Saveroutine fixed. Some games bank out basic before saving and could cause the save to fail (e.g. highscore).
* Filecopy temporarily limited to 152 blocks because of the savefix.
2017-04. Version 1.0 (Obsolete. Don’t use)
* Initial release.


* Jiffydos protocol and DOS wedge.
* Customizable color scheme.
* Customizable F-Key assignments.
* Built in filebrowser(FB) supporting 590 entries.
* Built in file copier.
* md64/md71/md81 to make a d64/d71/d81 image.
* CRSR moves to beginning of the line when executing F-Key.
* When loading a file, the start- and end address are displayed.

Tape- and RS232 support are not available.

Use the patcher to create JaffyDOS ROM. You must provide an original Jiffydos ROM and be a licensed Jiffydos user to use JaffyDOS in your system. You can purchase Jiffydos from http://store.go4retro.com/


Thanks to Tom-Cat, Erhan and Lemming for feedback and extensive testing. Your help made it possible! 🙂
Additional testing for version 1.1 done by Snear and Marty/Radwar.


No warranties whatsoever, use it at your own risk 🙂






Enter the filename of the original Jiffydos ROM.


Create a personal color scheme or select one of the predefined schemes.


The F-key commands can be re-assigned.






Default F-key assignments: (customizable with the patcher)
F1 = @"$"       DIR<CR>
F3 = %          LOAD and RUN<CR>
F5 = @"CD/:     CD directory/mount diskimage<CR>
F7 = @"CD<-"    CD parent dir<CR>
F2 = /          LOAD<CR>
F4 = @"XS/:     Mount swaplist<CR>
F6 = @  "S:     Scratch file
F8 = @FB:       Start FileBrowser<CR>

<CR> Executes the command automatically after pressing the F-Key.



DOSWedge Commands:
@                   Read disk drive error channel
@$                  Display disk directory
@#device            Set device number
@C:newfile=file     Copy a file on the same diskette
@I                  Initialize disk drive
@N:diskname,ID      Format (NEW) disk
@N:diskname         Short NEW
@Q                  Disable JaffyDOS
@R:newname=oldname  Rename file
@S:file             Scratch file
@UJ                 Reset disk drive
@V                  Validate disk
/filename           LOAD program
£filename           LOAD program
%filename           LOAD and RUN program
↑filename           Load and RUN program
←filename           Save program
'filename           Verify program

<SHIFT>+<RUN/STOP>  Load & run first program on disk
<CONTROL>+<D>       Default drive toggle
SYS 64000           Re-enable JaffyDOS functionkeys and commands



New DOSWedge Commands:
&filename               Verify program
$                       Display disk directory
@8                      Set device number to 8
@9                      Set device number to 9
@1x                     Set device number to 1x
@FB                     Start FileBrowser (or @F)
@MD64"filename.d64      Make .d64 image
@MD71"filename.d71      Make .d71 image
@MD81"filename.d81      Make .d81 image



Make image; D64, D71 or D81:
* Use single quote only in the command.
* Max 16 chars in filename+extension(.D64/.D71/.D81).
* File extension is mandatory.
* You must mount and format the diskimage afterwards.


SD2IEC Supported commands:
See the SD2IEC readme-file here
JaffyDOS does not require extra quotes in some of the commands.


Additional commands which are not mentioned here but are referenced in the Jiffydos manual, have been removed to fit the new features in JaffyDOS.


CRSR UP    = Up one position.
CRSR DOWN  = Down one position.
CRSR LEFT  = Up 10 positions.
CRSR RIGHT = Down 10 positions.
F1         = Go to First entry in the list.
F2         = Refresh.
F3         = Go to Last entry in the list.
F7         = Quit.
RETURN     = Load & Run / Enter dir / Mount image or swaplist.
Backspace  = Exit dir / Unmount image.
$          = Display "real" dir.
+/-        = Increase/Decrease device number.
CBM C      = Filecopy. Load(copy) file into memory, see below.
CBM V      = Filecopy. Save(paste) file to disk, see below.

* 590 entries allowed in directory.
* Remembers last position when returning from a directory or unmounting an image (one level).
* Files with extension .D64/.D71/.D81/.M2I/.DNP are mounted as disk images using @CD:
* Files with extension .LST are mounted as a swaplist using @XS:
* Character set is changed to uppercase when entering a diskimage.


Filecopier (for small files, only available in FileBrowser)
1. Hold down the CBM-key and press “C”. Selected file will be loaded into memory.
2. Go to destination location with filebrowser.
3. Hold down the CBM-key and press “V”. File is now saved into current location.

* A file can be copied from/to the SD2IEC filesystem, a mounted image or swaplist, or from/to another device number/type.
* It is not possible to copy(CBM-C) a directory or a disk-image.
* Selecting / copying multiple files is not supported.
* You can not paste(CBM-V) if a file has not been loaded or if the copy phase resulted in an I/O error.
* I/O Errors will be reported.
* Max filesize: 201 blocks. (exceeding the size will cause a crash).
* File can be re-saved(CBM-V) several times at multiple locations.
* You have to re-load a file (CBM-C) if you exit and return to FB.