
                      1670/1680 MAC SERIES
                         Specifications

The Micropolis Macintosh-Compatible disk drives are designed
especially for Value-Added Distributors and Resellers of Macintosh
storage systems and sub systems.

Compatible with Mac Plus, Mac SE, Mac II, and Mac IIx computers.
  Half-height form factor adapts easily to Mac II and Mac IIx    
    systems.
  Half-Height form factor adapts for low profile external        
    package integration.
  The drives employ a closed-looped digital servo which ensures  
    accurate tracking under all environmental conditions.
  Macintosh-compatible SCSI interface permit easy integration,   
    eliminating the need for cable modification.
  SCSI features include:
    A full 64 Kbytes buffer with read-ahead capability for faster 
      data access
    Less than 600 microseconds command overhead to improve       
      overall throughput numbers
    Cylinder oriented defect management, offering the most       
      reliable data integrity system available

  Formatted Capacity:              Model Number

  Model                   1673-5                   1674-7
  Total Mbytes               112                      158
  Bytes Per Sector  -------------------- 512 --------------------
  Sector Per Track  --------------------- 36 --------------------
  Cylinders         ------------------- 1245 --------------------
  Data Heads                   5                        7

  Formatted Capacity:              Model Number

  Model                   1683-4                   1684-7
  Total Mbytes               193                      340
  Bytes Per Sector  --------------------- 512 -------------------
  Sector Per Track  ---------------------  54 -------------------
  Cylinders         -------------------- 1777 -------------------
  Data Heads                   4                        7

1670 Performance

  Seek Time (includes settling)            Track to Track  4 msec
                                           Average        16 msec
                                           Maximum        37 msec
  Latency Time(average)                                 8.33 msec
  Rotational Speed                                  3600 rpm+/-5%
  Media Transfer Rate                                      10 MHz

1680 Performance

  Seek Time (includes settling)            Track to Track  4 msec
                                           Average        14 msec
                                           Maximum        30 msec
  Latency Time(average)                                 8.33 msec
  Rotational Speed                                  3600 rpm+/-5%
  Media Transfer Rate                                      15 MHz

Interface                                                Mac SCSI

Features

  Command Overhead                     Less than 600 Microseconds
  Buffer                                     64 KByte with parity
  Defect Management                             Cylinder oriented
  Data Integrity
    Automatic Retry with early/late strobe, track offset
    48 bit ECC polynomial
    Parity through buffer

Form Factor             (Industry standard for 5 1/4 half-height)
  Height                                   1.625 inches (41.3 mm)
  Width                                   5.75  inches (146.1 mm)
  Depth                                   8.00  inches (203.2 mm)
  Weight                               5 pounds (2.27 kg) maximum

Other Specifications

Power Requirements

  + 12V +/- 5%                                            1.0 Avg
                                     2.0A Maximum during start-up
  + 5V +/- 5%,                                           1.9A Avg
Power Dissipation, typical                               15 Watts
Acoustic Noise
  Idling                                                   40 dBA
  Seeking                                                  45 dBA
Mounting       Half-height 5 1/4 inch disk drive, any orientation

Reliability
  MTBF                                       150,000 power-on hrs
  MTTR                                                 15 minutes
Preventive Maintenance                                       none
Electronic Adjustments                                       none
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