Tandy by AST  (12-91635,12-97721)  Seagate ST-3660A   Faxback Doc. # 14418
              (12-97722,12-97723)  545 MB IDE Drive
              (12-97724,12-97725)  Specifications
              (12-97731,12-97732)
              (12-97733)

Formatted Capacity (max)                                          545.5 MB
Tracks                                                          See note 1
Cylinders                                                       See note 1
Average Access (ms)                                                     14
Single Track Seel (ms)                                                   5
Max Full Seek (ms)                                                      34
Power Requirements:                               +12V Start-up (amps) 1.1
                                                  +5V Start-up (amps) 0.35
                                                      Start-up (watts) 8.5
Power Management (Watts):                                      Active 5.23
                                                                IDLE 1.865
Write Precomp (cyl)                                                    N/A
Reduced Write Current (cyl)                                            N/A
Landing Zone (cyl)                                                    AUTO
IBM AT Drive Type                                               See Note 1

Note 1:

The IBM AT drive type may require formatting and partitioning software.  
Also, check to see if your CMOS setup has a "custom" or "user definable"
drive type available.  

Possible translations:

     This translation is generally acceptable, as is, for non-DOS
     operating systems (i.e. Xenix).
          1057 cyl, 16 heads, 63 sectors = 545,513,472

     DOS operating systems may require a system bios that accepts or 
     translates larger values for the CMOS head parameter which lowers 
     cylinders below 1024.
          528 cyl, 32 heads, 63 sectors = 544,997,376

     Other full-capacity solutions for DOS operating systems include 
     third-party drive preparation software, system BIOS which supports 
     LBA mode or BIOS driver host adapters.  Otherwise, the capacity may
     be limited to:
          1024 cyl, 16 heads, 63 sectors = 528,482,304
     (This is the setup selection used on the Tandy by AST machines).

Note 2:

Since a User-definable or Custom translation geometry may be used, it is
imperative that the values be written down and kept with your permanent
records for retrieval in the event of CMOS battery failure.

Jumper Settings:

The options jumpers are located on the bottom of the drive.  The pins are
numbered 1 through 8, with pins 1 and 2 towards the front of the drive.

               8 o-o 7           (back of drive)
               6 o-o 5
               4 o-o 3
               2 o-o 1           (front of drive)

When used as only drive in system, no jumpers should be installed.  When
used as a master drive in a two drive system, jumper pins 5 and 6.  When
used as a slave drive in a two drive system, jumper pins 7 and 8.  Note 
that there is a spare jumper parked on pins 1 and 3.

(TMC-03/28/95)