SEAGATE TECHNOLOGY, INC. Customer Technical Support FAX Network +1 408 438-8137 Customer Technical Support Bulletin Boards (300-9600, 8-N-1) 旼컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴커 � United States +1 408 438-8771 � United Kingdom +44 628 478011 � 쳐컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴캑 � Germany +49 89 140-9331 � Singapore +65 227-2217 � 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컨컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴켸 (C)opyright 1991 ST-3550N Rear View 旼 50 pin SCSI Interface I/O connector � � DC power (TOP) 郞袴袴袴袴袴� 袴袴袴袴袴拷 /�5횳횳�12\ 袴袴�::::::::::::::::::::::::1팠� 0 0 0 0 팠 (BOTTOM) 突袴袴袴袴袴袴袴袴袴袴袴袴� 읕컴컴컴컴� 旼컴컴1 旼컴컴1 旼컴컴1 읕컴컴� 읕컴컴� 읕컴컴� Terminating Resistor Packs ST-3550N Left View o o o1 (TOP) o o o 郞� Front....袴袴袴袴袴袴袴袴袴妄妄妄袴袴� I/O connector � � � 突� SCSI Address ID 1 켸 � � ID 2 컴켸 � ID 4 컴컴켸 ST-3550N Right View o o4 o o o6 (TOP) 郞� 1o쿽 1o쿽 o DC Power 팠袴曲袴袴袴 � 袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴 突� � � � 컴좔컴� � Active/Passive Termination 컴좔� 컴쩡컴� Terminator Power 旼컴좔컴컴컴컴컴컴컴컴컴컴컴컴컴커 컴쩡� � Active: Pins 1 & 2 shorted � � � only (+2.85V to � � � 110 �) for FAST � � � SCSI; � � 쿛assive: Pins 2 & 4 shorted � � � AND pins 5 & 6 shorted � � � (+5V and GND to � � � 220/330 �) for � � � standard SCSI. � � 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴켸 � 旼컴컴컴컴컴컴좔컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴커 쿟erminator Power: From SCSI Connector 컴컴컴컴컴컴컴컴 Pins 1 & 2 � � From Power Connector 컴컴컴컴컴컴컴� Pins 1 & 3 � � To SCSI Connector Only 컴컴컴컴컴컴� Pins 3 & 4 � � From Power Connector and 컴컴컴컴컴� Pins 1 & 2 AND � � to SCSI Bus --------------------------- 3 & 4 � � Terminating Resistors not Installed � Pins 2 & 4 � 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴켸 ST-3550N Front View 旼컴컴컴컴컴컴컴컴� SCSI ID's (none for ID0) � not used if ID set on side jumpers � 旼컴컴컴컴컴컴� Ext. Spindle Clock Synch � � pin-5 is Clock Ground � � 旼컴컴컴컴컴� Remote LED (TOP) 旼좔� � � 旼컴컴� Reserved 4 2 1 � � 旼컴좔컴� o o o o o-o o o o o 1o o o o o+o o o o o o o o o+ 袴袴袴袴袴袴袴袴袴袴1o o o o-袴袴袴袴袴袴袴袴 � � � � (BOTTOM) � � � 읕� Remote LED � � 읕컴� Ext. Spindle Clock Synch � � pin-5 is Clock Ground � 읕컴컴� Remote Start Enable 읕컴컴컴� Parity Enable ST-3550N UNFORMATTED CAPACITY _____________________ FORMATTED CAPACITY (xx SECTORS) __________456.5 AVERAGE SECTORS PER TRACK ________________83 rounded down ACTUATOR TYPE ____________________________ROTARY VOICE COIL TRACKS ___________________________________10,630 CYLINDERS ________________________________2,126 (user) HEADS ____________________________________5 DISCS (3.5 in) ___________________________3 MEDIA TYPE _______________________________THIN FILM HEAD TYPE ________________________________THIN FILM RECORDING METHOD _________________________ZBR RLL (1,7) INTERNAL TRANSFER RATE (mbits/sec) _______21.6 to 36.3 EXTERNAL TRANSFER RATE (mbyte/sec) _______4 Async EXTERNAL TRANSFER RATE (mbyte/sec) _______10 Sync SPINDLE SPEED (RPM) ______________________4,500 AVERAGE LATENCY (mSEC) ___________________6.67 BUFFER ___________________________________256 Kbyte SeaCache Multisegmented, read look-ahead INTERFACE ________________________________SCSI-2 Fast BYTES PER TRACK __________________________42,943 avg. SECTORS PER DRIVE ________________________891,574 TPI (TRACKS PER INCH) ____________________2,400 BPI (BITS PER INCH) ______________________52,602 AVERAGE ACCESS (ms) ______________________12 SINGLE TRACK SEEK (ms) ___________________<4 MAX FULL SEEK (ms) _______________________32 MTBF (power-on hours) Office _____________250,000 POWER REQUIREMENTS: +12V START-UP (amps) _1.9 POWER MANAGEMENT (Watts): ACTIVE _______________5.75 IDLE _________________3.0 STANDBY ______________1.0 WRITE PRECOMP (cyl) ______________________N/A REDUCED WRITE CURRENT (cyl) ______________N/A LANDING ZONE (cyl) _______________________AUTO IBM AT DRIVE TYPE ________________________0 Formatted at the factory with 2 alternate cylinders. Total physical cylinders equal 2128. Physical: Height (inches/mm): 1.00/25.4 Width (inches/mm): 4.02/102.1 Depth (inches/mm): 5.77/146.6 Weight (lbs/kg): 1.5/0.68 Note: If FAST SCSI transfer rates are used, then the active termination options must be used. If the transfer rates are 5.0 MBytes/sec and below, either method of termination can be used. Although active and passive terminated devices can be installed on the same bus, both ends of the cable should be terminated in the same manner, either both active or both passive. Note: If your application requires no terminators, remove the terminators from the circuit board. Merely removing the terminator power source selection jumper does not disconnect the terminator resistors from the circuit. ZBR = Zone Bit Recording = Variable sectors per track Seagate reserves the right to change, without notice, product offerings or specifications. (08/08/94)