[AQUARIUS] Quick Disk ROM disassembled

[Bruce Abbott]

This is my attempt at disassembling the Quick Disk ROM to find out how the DOS commands work. It may also be interest for producing equivalent hardware, for adding Quick Disk functions to an emulator, or just to 'see how they did it'.

 

I don't have an actual Aquarius Quick Disk drive, and I was unable to find any information on its interface. However I guessed that it would be similar to those used in other Z80 based systems, such as the Sharp MZ-1F11. I found a block diagram which uses a Z80 SIO as the disk drive interface. This seems to match up with the code in the the Aquarius DOS ROM.

 

The Quick Disk Drive works a bit differently to a normal floppy disk. It has a spiral track which the head follows from start to finish, then returns to 'home' and repeats the motion if the drive motor signal is held on. In effect it is like a floppy disk with only one track - but that track is a big one, storing 40 sectors of 1280 bytes each. With no track stepping and such to worry about, this system should be fairly easy to emulate. It should also be easy to increase capacity, simply by increasing the number of sectors.

 

AQUARIUS DOS BASIC adds the useful ability to work with machine code programs. However this is not compatible with tape commands, and (as far as I know) no disk-based software exists that makes use of it. So the question is; is there any point in trying to reproduce the functionality of the Quick Disk drive with modern hardware, or is it just a quaint piece of history that is best forgotten?

 

 

Aquarius DOS BASIC 1_1.zip

[Aquaman]

I only know one person who ones one and that will be Martin. http://www.vdsteenoven.com/aquarius/quickdsk.html

 

Maybe he can help you out, but he hasn't been on the forum for a while.

 

In my humble opinion it was a nice piece of hardware in that time period, but nowadays better options are available!