I recently found myself needing to create a few CP/M data packs for customers. This is normally no problem, but I needed to load them with programs. Since I normally use the VDD all of my files are in disk images, and a CP/M disk image is limited to 160kb, where as a CP/M data pack image is 256kb. The total amount of the programs was around 200kb so I would need to import files from the PC into 2 CP/M disk images, move those images via microSD card to an Adam and then copy those to a CP/M data pack. This is very tiresome and if you have ever copied files under CP/M it really abuses the data drive. For other purposes under EOS, I normally just copy disk images to data packs and let Backup+ 3.0 correct the directory. This is a simple block copy and it works fast.
So I thought to myself, why not take the tape image with is 256 1kb blocks in sequential order and interleave the 256 byte records so it is now a 256kb disk image. The VDD does not care what the size of the image is. Then I can just use File Manager to do a block copy and have the CP/M image on tape. in one pass, no copying of individual files and abusing the data drive.
Included in this post is a DOS program (requires DOSBOX under windows 7 and up) that takes a data pack image (.ddp) and makes a disk image (.dsk) for you. I am also including the source code in Turbo Basic so you can see how it works.
- Download ddp2dsk.zip
The following zip file has a copy of the Dragon’s Lair Data Pack image and a conversion to a 256kb disk image which you can use with the VDD or in your emulator or copy back to a data pack using the File Manager Method above.
- Download Dragons Lair.zip
This zip file contain’s the data pack game “2010 – The Text Adventure Game” converted into an interleaved disk image as the disk image does not contain the ending sequence.