The MIO includes a powerful built in SASI/SCSI interface. This allows you to connect any SASI (sassy) or SCSI (scuzzy) device to your Atari providing you have the proper support software. SASI (Shugart Associates Systems Interface), developed by Shugart first, is a subset of SCSI (Small Computer Systems Interface). SCSI is the more recently adopted "standard" for small computer systems other than IBM. SASI/SCSI controllers typically interface with an ST-412 or ST-506 hard drive. ST-412 or ST-506 is the standard interface used on most 'bare bones' 5 1/4 inch hard drives in use today. The MIO will physically (electronically) work with all SASI/SCSI controllers but we cannot guarantee to have format software for every possible configuration. (SASI controllers usually use the standard SASI format routine. SCSI controllers typically need special routines for each brand.)

Controllers not supported with format routines

If you have a SASI or SCSI controller or drive not supported by our HDFMTPHx.COM program, we may modify our format routine to handle it. You must send us your controller (or drive) and its technical manual along with our special service fee of $45. Please call our technical support department before sending in your system. We may already have the necessary format routine written.

Initialization Sequence if Using SpartaDOS on your hard drive.

The following is a brief description of the steps necessary to set up a hard disk drive using SpartaDOS 3.2.

1. Connect the hardware - includes use of proper cables, proper termination, and drive ID assignments. For more information, refer to Chapter 2.
    
2. Set MIO configuration - includes interface types, heads, cylinders, and ID/LUN. This is how HDFMTPH.COM will find your hard drive. If you are going to partition your hard drive, you must set the configuration for each drive unit number ("D1:" - "D8:") and the parameters must match. Refer to Chapter 3 for configuration instructions.
    
3. Physically format the disk - use HDFMTPH.COM and make proper menu selections for your controller. Note that if partitioning a drive, several drive numbers will follow the drive number selection. Be careful since you do not enter the drive number but rather a selection number.
    
4. Partition the drive - only necessary if you made two or more drive numbers ("D1: - "D8:") point to the same physical drive. The partitions are set up by simply giving a start and end sector number (the HDFMTPH.COM program displays the total number of sectors on the hard drive) in the MIO Configuration Menu. Read the next section for more information on setting Start/End sector numbers.
    
5. Save the configuration by pressing '4' and then 'Y' in the MIO Configuration Menu. Note: the configuration is written to sector 0 of the drive with the ID/LUN of 0,0.
    
6. Directory build - use HDFMTDI.COM which writes the SpartaDOS directory structure to the hard disk. This should be repeated on each drive partition. When asked which drive number, enter 1 through 8 (for "D1" through "D8:"). This is not to be confused with either the bus ID of the drive or the drive selection number in the HDFMTPH.COM program.
    
7. Copy SpartaDOS 3.2 to each partition you plan on booting from. (Simply use the COPY command — this is documented in the SpartaDOS Construction Set Manual.) Next, use the BOOT command to assign the DOS as the boot program. (Type "BOOT Dn:X32D.DOS" where 'n' is the drive you copied DOS to — refer to the SDCS manual for more information on the BOOT command — this is about the least understood and easiest to use command in SpartaDOS.)

Initialization Sequence if Using MyDOS on your hard drive.

The following is a brief description of the steps necessary to set up a hard disk drive using MyDOS.

Follow steps 1-5 of the above sequence. Boot MyDOS and enter the menu. Set the drive configuration by pressing 'x' and answering 'Y' to the large capacity drive question and enter the total number of sectors (as displayed by HDFMTPH.COM). Next press 'I' (followed by the drive number) to initialize the directory, and finally use the 'H' command to write DOS files to that drive.

Formatting Your Hard Disk — More Complete Details

The following is a more detailed description of the processing of setting up your hard drives system. Up to this point, enough information has been given, but it may still not make sense. Therefore, the following goes through the process again attempting to make everything more clear.

System Configuration
The system configuration must be setup before attempting to format your hard disk drive. Hold down the SELECT key and press RESET. You can release the SELECT key after the configuration menu appears. Device ID, Logical Unit Number, Heads, and Cylinders, must be set before performing the physical format. These tell the system drive location and size. Chapter 3 documents the configuration menu in detail in case you are not sure what to do.

Device ID
This is the SASI/SCSI bus ID. Jumper plugs (shorting type) on the controller are used to set the device ID. Set this to drive #0 if only using one drive. (0 is the only drive for loading and saving default configurations.) Values of 0 through 7 are valid. Device ID and Logical Unit Number (ID,LUN) are used so the system can identify individual physical drives. D1:, D2:, etc. are not valid ways to identify a particular drive anymore since the MIO allows you to swap drive numbers and partition a physical drive into more than one drive.

Logical Unit Number
The logical unit number (LUN) is determined by which 20 pin plug on a SASI/SCSI controller is used and by the drive number the hard disk itself is configured to. This will be 0 or 1 on most systems. Refer to your controller manual for plug locations. (One drive with an ID of 0 must be plugged into LUN 0 since that is where the configuration is loaded and saved.)

Heads and Cylinders
Refer to your hard drive manual for number of heads and cylinders. You may also refer to Appendix D which is a general chart of some common hard drives. Heads refers to the actual number of read/write heads inside your drive and cylinders are similar to tracks on a floppy disk. A typically 10 Meg drive may contain 4 heads and 306 cylinders or 2 heads and 612 cylinders.

Format (HDFMTPH.COM)
The physical format is created and verified by running the HDFMTPH.COM program. If using SpartaDOS, run this as a command file. (With another DOS, run this as a binary file.) Then select the proper interface type from the menu. CAUTION: Running the physical format totally destroys all previous information on the drive! This process is only needed the first time you set up your drive. A 20 Meg physical format will take about 30 minutes so be patient. When finished, the total number of available sectors will be displayed. Make sure you write this number down for each drive. This is the only time you will be told how many good sectors are available for partitioning. Defective sectors will be mapped out automatically by the controller. If the drive is not to be partitioned, then HDFMTPH.COM will automatically set up the Start/End+1 sector numbers in the configuration menu.

Partitioning
The hard drives must now be partitioned. The MIO is simply looking for a starting and ending sector for each drive. SpartaDOS can handle up to 16 Meg (16,776,960 bytes or 65535 sectors) per drive. Other DOS types may have smaller limitations. Check with the DOS publisher for specification. The format uses 256 byte double density sectors.

Assuming a 16 Meg limit per partition, if the starting sector is 1 (0 is always reserved), the maximum ending sector +1 should be 65536. The next partition should start with 65536 and end with a maximum ending sector number of 131071. (Add 65536 to get the next maximum.)

Directory Build (HDFMTDIR.COM)
HDFMTDIR.COM (directory build) writes the SpartaDOS directory structure to the disk drive. Run this command if you are using SpartaDOS as your system DOS. This command will also destroy any previous data on the partition of the hard disk that is written to.

If using MYDOS or other DOS types you will use the INIT functions and Write DOS functions instead of HDFMTDIR. See the DOS manual for more information.

Directory build should be run on each drive (D1:, D2:, etc.) used on the hard drive. The SpartaDOS module should then be copied to the partition to be used as D1: and the BOOT command used to assign the boot flag.

Example:   BOOT X32D.DOS <return>       (Assuming version X32D.DOS.)