Introduction:

The Hard Disk Interface allows hard disk storage to be quickly accessed by the parallel bus of an atari XL or XE computer.  
The output from the Hard Disk Interface is an industry standard Scsi bus, allowing the use of any Xebec compatible hard disk 
controller and any standard hard disk drive.  Other  types of SCSI controllers are being added to the line of compatible types.  
Included with the Hard Disk Interface is a high speed parallel printer port.  
The transfer rate of both the hard disk port and printer port is approximately 8 to 10 K  bytes per second.

The hard disk drive is divided into three sections or drives.  
Section 1 is configured as a standard "fake" floppy on the hard disk.  
Any standard Atari Dos may be used to access the "fake" floppy and standard serial floppy disk.  
The remaining large section cannot be used with most DOS's since they do not access enough sectors.  
To access up to 16 megabytes of hard disk storage the enclosed HD MYDOS can be used or you can purchase Sparta and use 
that DOS.

System Installation:

Hard Disk Interface

The Hard Disk Interface plugs into the parallel expansion bus on the right rear of the Atari XL and XE computers.  
If a XL computer is being used the plastic protective cover over the parallel bus connector must be removed.  
Simply snap it loose by prying on the middle top or bottom of the cover.  
If a XE  computer is being used a XE-to-XL adapter must be inserted into the cartridge and expansion slots on the XE computer to give it a XL compatible parallel bus.  
This adapter includes a seperate socket for cartridges and is avaiable from K-Products.





Hard Disk Sub-System:
     
     The Hard Disk Sub-System consists of:
     (1) A  hard disk with control board
     (2) A Scsi controller
     (3) A power supply and case

NOTE:

Some systems integrate numbers 1 and 2 into a single board.

A hard disk system requires a very sophisticated control structure to access the fast and large hard disk.  
The SCSI controller takes the commands from the computer interface and translates them into control signals for the disk control board.  The hard disk control board takes these signals and positions the head to read the data off the hard disk surface.  It then reads the very sensitive signals rom the hard disk and turns them into signals that can be processed by a SCSI controller.  The SCSI controller then sends the data back to the i