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Text File | 1994-06-30 | 28KB | 938 lines

(NOTE: contains all the typographical errors of the original!) DECPACK DISK CARTRIDGE SYSTEM - RK11-C/RK02, RK03 1. Introduction The DECpack cartridge disk drive and control is a complete mass storage system, offering an economical solution for large volume, random-access data storage. The system includes a modular mass storage device utilizing removable disk cartridges and a complete easy-to-program control. The DECpack is available in two models: The RK02 drive with over 600,000 words per drive; and the RK03 drive with over 1.2 million words of storage per drive. The DECpack is ideal where a large volume of programs and data are developed and maintained for one or more users. When used with PDP-11 software such as the Disk Operating System or RSTS-11 System, DECpack offers the flexibility of permitting each member of a group of users to maintain his own private program and data files. It is expandable up to 4.8 million words (RK02) or 9.6 million words (RK03) per controller. 2. Operation The removable disk cartridge offers the flexibility of virtually unlimited off-line capacity with rapid transfers of files between on-line and off-line without copying operations. It utilizes a cartridge similar to the IBM 2315, but with 12 sectors. Average total access time on each drive is 90 milliseconds. On expanded systems, operations are overlapped for efficiency; one drive may read or write while one or more additional drives are seeking new head positions for the next transfer. All data transfers utilize the Non-Processor Request facility during transfers. Each disk is permanently mounted inside a protective case that automatically opens when inserted in the disk drive. While on-line, dust contamination is prevented by a highly-efficient continuous "absolute" air filtration system. The DECpack provides accurate data storage and transfers by means of a write check function, correct cylinder verification by hardware, hardware checksum, and hardware maintenance features. There are no mechanical detents, thus a major source of wear and critical adjustment is eliminated. 3. Programming REGISTER ADDRESS Drive Status Register (RKDS) 777400 Error Register (RKER) 777402 Control Status Register (RKCS) 777404 Word Count Register (RKWC) 777406 Current Bus Address Register (RKBA) 777410 Disk Address Register (RKDA) 777412 Maintenance Register (RKMR) 777414 Data Buffer Register (RKDB) 777416 Drive Status Register (RKDS) Contains the current selected drive status and current sector address. It is a read only register. BIT NAME DESCRIPTION 15-13 Ident. of Drive(ID) If an interrupt is caused as a result of a SEARCH COMPLETE (Bit 13 RKCS) or a SEEK INCOMPLETE (Bit 9 RKDS) these bits will contain the binary representation of the logical drive number that caused the interrupt. 12 Drive Power Low(DPL) Set when an attempt is made to initiate a new function was actively in progress when the control sensed a loss of power to one of the disk drives. This bit is normally accompanied by bit 15 RKER(DRE) and is reset by a BUS INIT or a CONTROL RESET function. 11 High Dens. Drive(HDEN) Set to identify the selected disk drive as an RK03 and reset to identify the selected disk drive as an RK02. 10 Drive Unsafe(DRU) Indicates that an unusual condition has occurred in the drive and it is unable to properly perform any operations. Putting the RUN/LOAD switch in the LOAD position will reset the condition. If, upon putting the RUN/LOAD switch back to the RUN position the condition reoccurs the drive or associated power supply is inoperative and corrective maintenance procedures should be begun. Normally accompanied by bit 15 RKER. 9 Seek Incomplete(SIN) Indicates that due to some unusual condition a SEEK function was not completed within 180ms of initiation. A DRIVE RESET function clears this condition. This bit is normally accompanied by bit 15 RKER. 8 Sector Counter OK(SOK) Indicates that the selected drive sector counter (Bits 0-3 RKDS) is not in the process of changing and is ready for examination. 7 Drive Ready(DRY) Indicates that the selected disk drive is in the following condition: a) properly supplied with power b) loaded with a disk cartridge c) door is closed d) LOAD/RUN switch is in the RUN condition e) the disk is spinning f) the heads are properly loaded g) the disk is not in a DRU condition (Bit 10 RKDS). 6 Access Ready(ARDY) Indicates that the selected drive head mechanism is not in motion and the drive is ready to accept a new function. 5 Write Protect Status(WPS) Set when the selected disk is in WRITE PROTECTED mode. 4 Sect. Counter=Sect. Addr. Indicates that the disk heads are positioned over the disk addresses currently held in bits 0-3 RKDA. 3-0 Sector Counter(SC) Indicates the current sector address of the selected drive. This is the look ahead and will work for any disk cartridge with up to 16 sectors. Sector address 00 is defined as the sector which follows the sector that contains the index pulse. This is an important consideration when using the R/W ALL mode of operation. Error Register (RKER) (This is a read only register) BIT NAME DESCRIPTION 15 Drive Error(DRE) Set when an attempt is made to initiate a function, or when a function is actively in progress, while the selected drive is not ready or in some error condition or if any of te dirves in the system senses a loss of either AC or DC power. If this bit is found set the RK03 should immediately be referenced to discover the cause of the condition. 14 Overrun(OVR) During a READ, WRITE, RD/CHK or WT/CHK, operations on sector 13, surface 1 of cylinder address 312, were finished and the RKWC had not yet overflowed. This essentially is an attempt to overflow out of a disk drive. 13 Write Violation(WLO) Set if an attempt is made to write on a disk which is currently being write protected. 12 Seek Error(SKE) Set if the disk head mechanism is not properly positioned while executing a normal READ, WRITE, RD/CHK or WT/CHK function. 11 Programming Error(PGE) The R/W ALL bit (Bit 9 RKCS) or the RMT bit (Bit 10 RKCS) were set while initiating some function other than a READ or WRITE. 10 Non-Existent Memory(NXM) Set if memory does not respond within 20us of the time when the RK11 becomes Bus Master during a DATI or DATO NPR sequence. Because of the speed of the RK03 disk drive, it is likely that if a NXM does occur it will be accompanied by a DLT (Bit 7 RKER). 9 Data Late(DLT) Set when an NPR sequence is initiated before the previous one has completed. 8 Read Timing Error(RTE) Two or more consecutive read clock pulses were dropped by the disk drive. 7 Non-Existent Disk(NXD) An attempt was made to initiate a function on a non-existent drive. 6 Non-Existent Cylinder(NXC) An attempt was made to initiate a function on a cylinder larger than 312. 5 Non-Existent Sector(NXS) An attempt was made to initiate a transfer on a sector larger than 13. 4-2 Unused 1 Checksum Error(CSE) Set while performing a RD/CHK or READ function as a result of faulty recalculation of the checksum. Cleared at the initiation of any new function. This is a soft error. 0 Write Check Error(WCE) Indicates that an error was encountered during a WT/CHK function as a result of faulty bit comparison between disk data and memory data. Clears at the initiation of a new function. This is a soft error. Note: Bits 5 through 15 are all hard errors. They clear only by a BUS INIT or a CONTROL CLEAR function. Control Status Register (RKCS) BIT NAME DESCRIPTION 15 Error Set when any bit in the RKER is set. Processor reaction is dictated by Bits 6 and 8 RKCS. This read-only bit clears if all the bits in the RKER are cleared and if Bit 14 RKCS is cleared. 14 Hard Error(H.E.) Set when any of Bits 5-15 RKER are set by the control. Stops all controller action and processor reaction as dictated by bit 6 RKCS. This READ ONLY bit, along with bits 5-12 RKER, is cleared only by a BUS INIT or a CONTROL RESET function. 13 Search Complete(SCP) Signifies that the prvious interrupt was caused as a result of some previous SEEK or DRIVE RESET function. READ ONLY bit. Clears at the initiation of any new function. 12 Maintenance Mode When set, will inhibit any signals from being transmitted to or from any disk drive and will permit diskless operation of the RK11. Used in conjunction with the RKMR. 11 Inhibit Inc.(INH BA) Setting this bit inhibits incrementing the RKBA during a data transfer. Tis allows data to be transferred to or from any one bus address for the entire operation. 10 Format(FMT) FORMAT Mode must be used only in conjunction with the normal READ and normal WRITE function. This mode is used to format a new disk pack or to reformat any sector that may have been erased or damaged due to control or drive failure. In the FORMAT mode the normal WRITE operation is altered only in that the servo positioner is not checked for proper position before the write operation. Under a normal WRITE the header is re-written each time the associated sector is written. In this mode, the normal READ operation is altered in that only one word is transferred to memory per sector; the header word. Therefore, a 3-word READ function in the FORMAT mode will transfer 3 contiguous header words to 3 consecutive memory locations for software checking. For a 200-word transfer, 200 consecutive header words from 200 consecutive sectors will be read, and so on. 9 Read Write All(R/W A) Must be used only in conjunction with a READ or WRITE function. The drive performs part 1 of a normal SEEK function after which it searches for SC = SA. When found, the read amplifiers or write drivers are turned on and every 16-bits a word is transferred to or from memory until the RKWC overflows. This mode is used to simulate formats to be written or read on controllers other than the RK11. 8 Stop on Soft Error(SSE) If a soft error is encountered while this bit is set: a. and Bit 6 RKCS (IDE) is reset, all controller action will stop at the end of the current sector. b. and Bit 6 RKCS (IDE) is set, all controller action will stop and a Bus Request will occur at the end of the current sector. 7 Control Ready(RDY) Signifies that the control is no longer engaged in actively executing a function and is ready to accept a command. 6 Int. on Done Enable(IDE) The control will issue a Bus Request and interrupt to vector address 220 if: 1. A function has completed its activity; 2. A hard error is encountered; 3. A soft error is encountered and bit 8 RKCS is set. 5-4 Memory Extension(MEX) Reserved for extended bus addresses and is used in conjunction with the RKBA. These bits make up a two-bit counter that increments each time the RKBA overflows. A bus DATO to these bits overrides any overflow from the RKBA. They are read/write. 3-1 Function These bits indicate the binary representation of the function to be performed. The functions are: CONTROL RESET (000) WRITE (010) READ (010) WRITE CHECK (011) SEEK (100) READ CHECK (101) DRIVE RESET (110) WRITE LOCK (111) 0 Go Write only bit. Indicates the function encoded in bits 1 through 3 of RKCS. Stays set until one control actually begins to respond to the go command. Word Count Register (RKWC) Contains the two's complement of the total number of words to be affected by a given function. It increments by one after each word transfer. Current Bus Address Register (RKBA) Contains the Bus Address to or from which data will be transferred. The register is incremented by two at the end of each transfer. Disk Address Register (RKDA) BIT NAME DESCRIPTION 15-13 Drive Select(DR SEL) Contains binary representation of the logical drive number currently being selected. 12-5 Cylinder Address(CYL ADD) Contains binary representation of the cylinder address currently being selected. The largest valid number is 312. 4 Surface(SUR) When active lower disk head is enabled. 3-0 Sector Address(SA) Binary representation of the disk sector to be addressed. This register may be loaded only while the RK11 is in the ready state. Maintenance Register (RKMR) This register is provided for diagnostic purposes only and does not participate in the normal disk operations. 4. Cross Cylinder Operation Surface 0 is defined as the upper surface and is active when RKDA 04 is reset. If a tranfer is initiated that requires overflow from surface 0, the control will automatically change to sector 0 or surface 1. If a transfer is initiated that requires an overflow from surface 1, the control will automatically move the heads to the next contiguous cylinder, check for proper head positioning, and continue the transfer on sector 0 and surface 0 of the new cylinder. An attempt to overflow out of the last secotr of te last cylinder will result in an error condition. At the end of any transfer the RKDA is automatically incremented. 5. Hardware Poll The control is capable of having any or all of the drives performing a SEEK or DRIVE RESET operation at any one time. A HARDWARE POLL feature will identify the logical drive number in bits 13, 14 and 15 of the RKDS of any drive that has completed a SEEK or DRIVE RESET operation and cause an interrupt if bit 6 RKCS is set (IDE) and the control is in the READY state (bit 7 RKCS is set) and the control was not already attempting to cause an interrupt as a result of some other operation. Tis will occur even if Bit 6 RKCS (IDE) was not set when first initiating the SEEK or DRIVE RESET function. If two or more drives complete the function simultaneously, the control will interrupt once for each drive and identify each one in turn in the RKDS. Care should be taken in this situation to raise the processor interrupt status to level equal to or greater than that currently held by the RK11 or else a second interrupt will occur immediately after the first and the end result will be that the interrupt service routine has been interrupted. This situation will also occur if an attempt is made to initiate a SEEK to an address that the drive is already at since one interrupt will occur as a result of the SEEK or DRIVE RESET function having been successfully initiated and another to report that the heads have reached their destination, which will occur immediately because the heads are already there. 6. Interrupts Because of the format structure of the RK11-C, any interruption of a write sequence cannot be tolerated until the end of the sector because this would result in essentially an unformatted disk. Therefore, any outside interventioin of this operation is held off until the end fo the current sector, which includes the CONTROL RESET function and the PROCESSOR or BUS INITIALIZE signals. Therefore, all those functions, such as CONTROL RESET, SEEK and WRITE LOCK, which normally take only a few microseconds to initiate can actually take up to 3.3ms if initiated while writing. For this reason the SEEK and WRITE LOCK functions will cause an interrupt (if bit 6 RKCS is set) as soon as the function has been succesfully initiated. The CONTROL RESET, which cannot cause an interrupt under any cirumstance, can, therefore, take up to 3.3ms to complete. 7. Specifications RK02 Drive RK03 Drive 1 disk/drive 203 cylinders/drive: 128 data words/track 256 words/track 2 surfaces/drive: 1536 data words/track 3072 words/track 12 sectors/track: 307,200 data 614,400 data words/surface words/surface 1 to 8 drives/control: 614,400 data 1,228,800 data words/drive words/drives Access Times (including head settling; typical) Track to track: 15ms Average random move: 70ms Average rotation delay: 20ms Data Transfer Rate: 22.2 usec per word for RK02 drive 11.1 usec per word for RK03 drive Transfer Path: Non-Processor Request (NPR) Direct Memory Access Minimum Block Size: One sector (128 words for RK02 drive; 256 words for RK03 drive) Minimum Transfer: 1 word Density: 1100 BPI max. for RK02 drive 2200 BPI max. for RK03 drive Speed: 1500 RPM Environmental Requirements: 60 to 90 F and 20% to 80% relative humidity Model Designations Control: RK11-CA 117V +10% 50/60Hz RK11-CB 235V +10% 50/60Hz Bus Priority Level: BR5 Interrupt Vector Address: 220 ------ -- Ronald Copley, owner | As always, I'm interested in your old Informatiks | computer equipment. Particularly DEC, 1010 Township RD 78W | Pyramid, Sun and DG. Scottown OH 45678-9051 | +1.614.643.1340 | If you have Pink Fairies bootlegs, etc. <copley1@muvms6.mu.wvnet.edu> | *please* contact me! --