Re: I wonder if it would be complicated to design...

[Jonno Downes <jonnosan@gmail.com>]

> 
> Don't forget, the first hard drive for the original Macintosh connected 
> 
> via the floppy port.  The original intent was to use the serial port, but 
> 
> then they discovered it was too slow.  Third parties put the drive inside, 
> 
> adding an interface to the motherboard.  But Apple's first hard drive used 
> 
> the floppy port.
> 
> 
> 
> I have no details of how that wsa done, but there must be enough signal 
> 
> lines to do it.
> 

With the notable exception of the Disk ][ (as currently being discussed in another thread), whether talking to a floppy drive, a hard disk, or a flash drive, the interfaces are all essentially the same, namely the computer transmits the address of a block of data, and then either the computer sends the data to be written to that block to the controller (i.e. a WRITE), or the controller sends the data already on that block to the computer (a READ).

The most significant variation to the interfaces due to different physical mediam (floppy/hard/flash) will be in the addressing format which will have been built using assumptions about capacity inherit in that medium (i.e something access a floppy drive will probably be restricted to only 1 byte each for track and sector number, the PC standard for early hard drives limited addressing to 22 bits (which limited disk size to 2GB) etc.

But with appropriate firmware and drivers, any of these addressing limitations can be worked around, and essentially any drive interface can be made to look like any other interface since they all work at the same conceptual level.

So to answer the original question, the complexity in building a new controller card that can interface to a 1.44MB floppy drive would be equivalent to that of interfacing to a CF, or a SCSI hard drive, or any of the other such things that already exist for the A2 platform.

Whether it is of equal utility is a different question of course...