M 8 4 2 5 S MINISCRIBE NO MORE PRODUCED Native| Translation ------+-----+-----+----- Form 3.5"/HH Cylinders 612| | | Capacity form/unform 21/ 25 MB Heads 4| | | Seek time / track 68.0/15.0 ms Sector/track 17| | | Controller SCSI1 SINGLE-ENDED Precompensation Cache/Buffer 1 KB DUAL-PORTED Landing Zone Data transfer rate 1.000 MB/S int Bytes/Sector 512 MB/S ext Recording method RLL 2/7 operating | non-operating -------------+-------------- Supply voltage 5/12 V Temperature *C 4 50 | -40 57 Power: sleep W Humidity % 8 80 | standby W Altitude km -0.061 3.048| idle 13.0 W Shock g 8 | 50 seek W Rotation RPM 3600 read/write W Acoustic dBA 50 spin-up W ECC Bit 32 MTBF h 20000 Warranty Month Lift/Lock/Park YES Certificates CSA,FCC,UL1950 ********************************************************************** L A Y O U T ********************************************************************** MINISC. 8425S PRODUCT MANUAL P/N 1052 REV. B, JULY 24, 1987 +---------------------------------------------------------+ | F1xx|Fuse | +------1 ++|XX | +------+ |||XX | Drive |||XX | Select RP3+|XX | ++|XX J1 | |||XX | |||XX ++ RP2+|XX ++ ++|XX | |||XX | |||XX | RP1+|XX | |XX | | 1 | | +---------------------------------------------------------+ XXXXXX J3 Power ********************************************************************** J U M P E R S ********************************************************************** MINISC. 8425S PRODUCT MANUAL P/N 1052 REV. B, JULY 24, 1987 Jumper Setting ============== Drive Select ------------ +-----------+ |o o o o o 1| |o o o o o o| +-----------+ | | | | | +- SEL 0 | | | | +--- SEL 1 | | | +----- SEL 2 | | +------- D (Disable Parity) | +--------- E (Low Powered) +----------- F (Diagnostics) Addressing ---------- Communication on the SCSI bus is allowd between only two (2) SCSI devices at any given time. There is a maximum of eight (8) SCSI devices. Each SCSI device has an SCSI ID bit assigned. When two (2) SCSI devices communicate on the SCSI bus, one acts as an Initiator and the other acts as a Target. The Initiator originates an operation and the Target performs the operation. An Initiator may address up to eight (8) Logical Units (LUN) attached to one Target. The M8-SCSI has only one Logical Unit Attached (LUN = 0). Address selection on the M8-SCSI is accomplished by the use of three jumpers: | 0 1 2 3 4 5 6 ------+-------------- SEL 0 | 0 1 0 1 0 1 0 SEL 1 | 0 0 1 1 0 0 1 SEL 2 | 0 0 0 0 1 1 1 When left OPEN, the corresponding bit is a ZERO (0). Mode Jumpers ------------ Three additional jumpers are supplied on the M8-SCSI Printed Circuit Board (PCB) with the following functions when SHORTED: Jumper D Disable Parity Jumper E Low Power/Auto Park Mode Jumper F Invokes Offline Diagnostics following reset, which consists of infinite seek tests (random or oscillating). ********************************************************************** I N S T A L L ********************************************************************** MINISC. 8425S PRODUCT MANUAL P/N 1052 REV. B, JULY 24, 1987 Notes on Installation ===================== Recommended Mounting Configuration ---------------------------------- The MiniScribe 8425 SCSI quarter size drive is designed to be used in applications where the unit may experience shock and vibrations at greater levels than larger and heavier disk drives. Two features which allow greater shock tolerances are the use of rugged media and shock mounts. To take full advantage of the shock mounts, however, it is necessary to provide a 0.1 inch clearance on both the top and bottom of the drive. This clearance allows for move- ment of the drive during acceleration. The drive may be mounted in any attitude. The drive is mounted using 6-32 screws, 1/8 inch maximum penetration. The customer should allow adequate ventilation to the drive to insure reliable drive operation over the operating temperature range. Mechanically Isolated Mounting Points ------------------------------------- Four side mounting and four base mounting points are provided to the customer. Each mounting point is mechanically isolated from the head/disk assembly. Magnetic Field -------------- The externally induced magnetic flux density may not exceed 3 Gauss as measured at the disk surface. Read/Write Electronics ---------------------- One integrated circuit is mounted within the sealed enclosure in close proximity to the read/write heads. Its function is to provide one (1) of four (4) head selection, read preamplification and write drive circuitry. Drive Mechanism --------------- A brushless DC direct drive motor rotates the spindle at 3600 rpm. The motor/spindle assembly is dynamically balanced to provide minimal mechanical runout to the disks. A dynamic brake is used to provide a fast stop to the spindle motor when power is removed. Air Filtration System --------------------- Within the sealed enclosure, a 0.3 micron filter coupled with a breather filter provides over the drive life a clean, above atmospheric pressure environment to the heads and disks. Head Positioning Mechanism -------------------------- Four read/write heads are supported by a carriage mechaism coupled to the stepper motor through a rack-and-pinion motion translator. Read/Write Heads and Disks -------------------------- Data is recoreded on two (2) 95 mm diameter disks through four (4) low force, low mass Mini-Winchester type ferrite heads. Caution/Warning --------------- The Miniscribe drive is a precision product weighing 1.8 pounds. During handling the unit must not be dropped, jarred or bumped. Otherwise, damage to the heads and disks may occur. When the drive is removed from the Miniscribe shipping container and not immediately secured within a chassis through its shock mounts, it must be stored on a soft padded surface. Failure to comply with the above procedure will render null and void all warranties. Electrical Interface -------------------- The Small Computer System Interface (SCSI) on the M8-SCSI uses single ended drivers and receivers, which allow a maximum cable length of 20 feet (6 meters) from the first to the last device (up to 8 devices) on the bus. All assigned signals are terminated with 220 ohms to +5 volts and 330 ohms to ground at each end of the cable. All three (3) terminator networks on the M8-SCSI are removable. All signals driven by the M8-SCSI are Open Collector and have the following output characteristics: Signal Assertion 0.0 VC to 0.4 VDC Max. Driver Output 48 mA (sinking) @ 0.5 VDC Signal Negation 2.5 to 5.25 VDC All signals received by the M8-SCSI shall have the following input characteristics: Signal True 0.0 VDC to 0.8 VDC Max. Total Input Load -0.4 mA @ 0.4 VDC Signal False 2.0 to 5.25 VDC Min. Input Hysteresis 0.2 VDC J1 SCSI Connector ----------------- A 50 pin flat ribbon connector is provided at J1. The 3M P/N 3425- 3000 cable connector is recommended. Pin 26 Term Power Termpower is +5 volts thru a 1 amp microfuse. Loss of this fuse will result in the disk drive appearing dead. Reversal of the connector with pin 25 grounded will cause this fuse to blow. J3 Power Connector ------------------ Power is applied through J3, a 4 pin AMP connector. The recommended mating connector is AMP P/N 1-480424-0 utilizing pins AMP P/N 350078-4. +-----J3-----+ pin 1 +12 VDC | 4 3 2 1 | pin 2 +12 Volts Return +------------+ pin 3 + 5 Volts Return pin 4 + 5 VDC Cable Connection ---------------- Single Host, Single Drive +-------+ +-------+ | HOST +----SCSI-Bus--------+ M8-S | | X+--------------------+ X| +-------+ +-------+ Single Host, Multiple Drives +-------+ +-------+ | HOST +----SCSI-Bus--------+ M8-S | | X+------+ +----------+ | +-------+ | | +-------+ | | +-------+ | +----------+ M8-S | | +----------+ | | | +-------+ | | +-------+ | +----------+ M8-S | +-------------+ X| +-------+ Multiple Host, Multiple Drives +-------+ +-------+ | HOST +----SCSI-Bus--------+ M8-S | | X+------+ +----------+ | +-------+ | | +-------+ | | +-------+ | +----------+ M8-S | | +----------+ | | | +-------+ +-------+ | | +-------+ | HOST +------+ +----------+ M8-S | | X+--------------------+ | +-------+ +-------+ X = Terminator Installed ********************************************************************** F E A T U R E S ********************************************************************** MINISC. 8425S PRODUCT MANUAL P/N 1052 REV. B, JULY 24, 1987 Introduction ------------ The MiniScribe M8-SCSI (Small Computer System Interface - ANSI X3.131-1986) series of 3 1/2 inch disk drives are half height random access storage devices of 21 Megabytes of formatted data (25 MB un- formatted) containing 2 plated disks and utilizing Winchester style flexure technology. High performance and high unit reliability are achieved by the utilization of a proven microprocessor spin control and rack-and- pinion stepper mechanism. The heads, disks and actuator assemblies are within a sealed enclosure containing recirculating and breather filters to supply clean air and equalized pressure to the head and disk environment. Quality mechanical construction with a sophistica- ted single printed circuit board allows for maintenance-free operation throughout the life of the drive. The M8-SCSI series disk drive uses the industry standard Small Computer System Interface (SCSI) compatible interface capable of up to 1 Megabyte/second (8 megabits/second) data transfer rate. The drive also features power up, user invoked or offline diagnostics and has full support of disconnection. Defect handling is entirely transparent to the host system as well as seek retry and error correction. The unit size and shock mounting are identical to the industry standard half height 3 1/2 mini floppy mounting dimensions and it uses the same power connector. Track Zero Detector ------------------- The Track Zero Detector resides on the stepper motor. This optical sensor consists of a light source and a receiver which when blocked by an interrupter on the motor shaft indicates one of several logical Track Zero positions. The microprocessor determines the physical location of Track Zero from the redundant logical Track Zeros. Seek Time --------- +----------------------------------+--------+ | | 8425S | +----------------------------------+--------+ |Track-to-Track msec. typ. | 15 | +----------------------------------+--------+ |Average msec. typ. | 68 | | msec. max. | 150 | +----------------------------------+--------+ |Latency msec. avg. | 8.33 | +----------------------------------+--------+ Media Defect Criteria --------------------- All defects are preassigned from the factory. Host Interface and Data Buffer ------------------------------ The host interface and data buffer are integrated in one single semicustom circuit with the following features: ANSI X3.131-1986 compatible (SCSI) Host interface operating in Target mode only. Capable of Arbitration and disconnection. Parity generation and checking (user selectable). Dual ported 1024 bytes buffer, eliminates the need for sector inter- leaving (1 to 1). Defect Management ----------------- There is one (1) alternate block allocated for each cylinder for a total of 612 allocated alternate blocks. This assures adequate coverage defective blocks and decreases the time necessary to react to alternate blocks. Diagnostic and Exercise Routines -------------------------------- The microprocessor performs wake up diagnostics upon application of power. If an error is detected, the processor will flash a warning by blinking the activity LED. Some errors are fatal in that they do not return to the program until power is cycled. If no errors are detected, the processor tests Jumper E to determine its state (open or closed). Briefly, Jumper E (Drive Exercise Options) is as follows: Power-up sequence of events is as follows: 1. Apply power 2. The microprocessor runs power on diagnostics and then allows motor spin up. 3. Test Jumper E. If open, go to normal operation. If closed, continue to Step 4. 4. Display code level (5 bits), e.g. 00001 5. Recalibrate access, then seek to maximum cylinder. 6. At this point the sequential seek burn-in will begin. Error codes may be generated by the microprocessor to indicate hard- ware failures or warnings that are detected during power-on diagnostics, burn-in mode, or normal operation. Error codes are diaplayed in a "morse-code" type manner. Bits may be interpreted and converted into hexadecimal error codes. "Zeros" are indicated by a short (1/2 second) flashingn mode. "Ones" are indicated by a short (1/2 second) continuous ON mode. Error "Words" are separated by a one second LED off time. Zero = 0.5 second flashing mode One = 0.5 second continuous ON mode Between Bits = 0.3 second Off Between Repeat Cycles = 1.0 second Off Listed Below are the binary to hexadecimal conversion values: 0 = 0000 4 = 0100 8 = 1000 C = 1100 1 = 0001 5 = 0101 9 = 1001 D = 1101 2 = 0010 6 = 0110 A = 1010 E = 1110 3 = 0011 7 = 0111 B = 1011 F = 1111 Message Definitions ------------------- Code 0 - Microprocessor RAM error Code 1 - Microprocessor ROM checksum error Code 2 - Interface chip diagnostic failure Code 3 - Write Fault latch will not reset Code 4 - Index pulse not detected during spinup Code 5 - Unable to reach 3600 rpm in 600 revs. Code 6 - Unable to stabilize spin speed in 10 seconds Code 7 - Unable to maintain spin speed to 0.5% Code 8 - Unable to uncover Track Zero sensor Code 9 - Unable to cover Track Zero sensor Code A - Track Zero interrupter misadjusted Code B - Shipping zone error, crash stop misadjusted Code C - Carriage stuck during recal error Code D - Seek errror during burn-in or recal Code E - No hall transitions during spin-up Code F - Unexpected interrupt from processor