иииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииии
        иии                                                         иии
        иии   зддд© зддд© здбд© зддд© б   б     зд© б зддд© здбд©   иии
        иии   Ё     Ё   Ё Ё а Ё цддды Ё   Ё ЧЧЧ Ё Ё Ё цд      Ё     иии
        иии   юддды юддды а   а а     юддды     а юды юддды   а     иии
        иии                                                         иии
        иии     здд© © здд©   здд© здд© з      © б  б б  б здд©     иии
        иии     здды Ё   д╢ д   д╢ Ё  Ё цдд© д Ё юдде юдде    Ё     иии
        иии     юдды а юдды   юдды юдды юдды   а    а    а    а     иии
        иии                                                         иии
        иииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииии

                                 Compliments of

                 The  P e r S t o r   S u p p o r t    B o a r d

                               FidoNet  1:102/523
                               AlterNet 7:401/523





     Perstor  Systems,   Inc.   is  an  emerging  leader  in  the 

development and marketing of high technology information  storage 

controllers.   Using  its  proprietary  Advanced  Data  Recording 

Technology  (ADRT)  Perstor has developed a controller line  that 

gives ESDI performance and capacity to ST506/412 Winchester  hard 

disk drives.  Five models are currently manufactured and marketed 

in this product line:   PS180-8XT,  PS180-8AT,  PS180-16F, PS180-

16FHP, and PS200-16F.

     The  most unique feature of the Perstor Controllers is  that 

they increase disk capacity by 90% to 100%.  Upgrading a  current 

system  is  often a better alternative to purchasing a brand  new 

system;  many  personal computer users want to make the  most  of 

their existing equipment.   A Perstor Controller enables the end-

user  to add storage capacity to his or her hard disk rather than 

buying a new one.  It also allows the distributor to increase the 

capacity  of  a  low  cost  hard disk  and  sell  it  as  a  more 

attractive, cost effective sub-system.  

     The  PS180  models  are  intended  for  use  with  ST506/412 

Winchester  disk drives of any form factor having oxide or plated 

media.  The  PS200 model is recommended for plated or  thin  film 

media  drives  having  high performance,  RLL  approved  internal 

circuitry.  All models also increase system speed by 10 - 100%

     The  16F  models include support for floppy disk  drives  of 

many capacities and form factors.   Customers using these  boards 

save  slot  space in the computer because one controller  handles 

two hard disks and two floppies.   More room is left for graphics 

cards, fax cards, and other peripheral boards.

     ADRT  consists of proprietary encoding,  signal  processing, 

and  extended  error checking and correction techniques based  on 

the  IBM  4300 and CD ROM technology.   This  unique  combination 

increases hard disk capacity and performance,  decreasing  errors 

at the same time. 

     Much  confusion  exists  in  the  industry  about  different 

controller  technologies  and their features.   Following  is  an 

outline  of  basic  differences  between  MFM,   RLL,   and  ADRT 

controllers:
                        MFM            RLL            ADRT (180)
Sectors per Track       17             26             31     
Capacity Increase*      0%             50%            90%      
Data Transfer Rate      5mbits         7.5mbits       9mbits
Data Write Rate         5mbits         7.5mbits       2.2 - 5.5
Compatible Drives       MFM            RLL            MFM & RLL
Error Correction        32 bit         32 bit         56 bit 

* in MFM format

     Standard  RLL controllers run at 7.5 megabits per second  in 

all phases of operation,  and this data rate tends to  overstress 

disk  drive media and cause data loss in drives specified for a 5 

megabit  data  rate.    In addition,  the 32 bit ECC  is  not  as 

effective as a 56 bit ECC at correcting any resulting errors.

     While  the effective data transfer rates achieved with  ADRT 

range from 9 to 10 megabits per second,  the rate of flux changes 

per  second  induced  on  the media surface  remains  within  the 

specified window margins of MFM disk drives.    These controllers 

also employ a larger error checking and correction code, allowing 

them to be used effectively and reliably with MFM drives.

     What does all of this technical jargon mean to you?   Simply 

that the Perstor ADRT Controllers increase capacity, performance, 

and reliability on a wide range of new and used hard disk drives.