DU-58 Disk System replacement for DEC TU58
The DU-58 Disk System is a disk storage device which replaces the DEC TU58 tape cartridge system. The system uses 3.5 inch diskettes which can be read on IBM compatible PC computers. Your PC can examine files formatted on the DU-58. The DU-58 Disk System is ideal as a small computer system device, an inexpensive mass storage system, software distributor medium, a diagnostics loader, and more. A dual drive DU-58 Disk offers up to 2.88 Mbytes of storage space, making it one of the most economical, complete disk mass storage systems available. HIGHLIGHTS
DESCRIPTION The DU-58 Disk System is a random access, mass memory disk subsystem in a light weight compact package. Ideal as a low cost storage device, the DU-58 Disk System can run on many major operating systems. It is capable of reading and writing data on block addressable formatted disks. Additionally, the data interchange capability of the DU-58 Disk System allows the user to write files using one operating system and read them back using another operating system. The DU-58 Disk System is an ideal diagnostic load device for use when the main systems device is inoperable. Diagnostics for CPU and the main storage device may be loaded from the DU-58 Disk System to restore them to operational status. The remainder of the diagnostics may then be loaded from that main storage device. Software and machine readable updates to operating systems can also be easily and economically distributed via the DU-58 Disk System. For example, run-time images can be developed on a large system, written on a DU-58 Disk System, and then physically carried to another system. CAPACITY The DU-58 Disk System has a capacity of 1.44 Mbytes per disk on each of two drives. The data is stored at fixed positions on disk referred to as blocks. This feature allows replacement of blocks of data in a random fashion, without disturbing information recorded previously. During the writing of data on the disk, the system positions itself by seeking the track and sector. Similarly, in reading, the same operation is performed to locate the data. The result of this feature is a fast average access time of 200 milliseconds compared with 9.3 seconds for the DEC TU58. THE CONTROLLER The controller module of the DU-58 Disk System incorporates a microprocessor that performs search operations for data blocks. It also handles the disk "housekeeping" functions such as data logging, formatting, and retries, to provide a simple communication protocol. DATA INTEGRITY The controller of the DU-58 Disk System employs a checksum to ensure accurate data recording and retrieval. The microprocessor automatically generates a checksum when a block of data is written, and similarly checks the character when the block is read. If an error is found, the device automatically rereads the disk up to three times before a hard error is indicated. This feature eliminates the host computer overhead normally associated with rereading soft errors. Data integrity is further ensured by a write-protect feature. The DU-58 Disk System has a write-lockout tab on the disk. A user need only insert the tab to write-protect a disk for the long or short term. RELIABILITY AND MAINTAINABILITY Low maintenance costs and high reliability are ensured on DU-58 Disk System by the simplicity of the mechanism's design. Each disk has a high-quality read/write head. The DU-58 Disk System is a complete subsystem. If one drive is down the other drive can still be used, thus enhancing its reliability OPERATING SYSTEM ENVIRONMENT The DU-58 Disk System is supported on various systems including the PDP- 11* systems running the RT-11*, RSX-11M*, RSX-11M-PLUS*, and RSTS/E* operating systems. It's also supported on VAX-11* systems running the VAX/VMS* operating system, and IBM PC/XT* systems running MS-DOS.
SPECIFICATIONS AND DESIGNS ARE SUBJECT TO CHANGE WITHOUT NOTICE. * DEC, PDP, RSTS, RSX, RT, VAX, AND VMS ARE REGISTERED TRADEMARKS OF DIGITAL EQUIPMENT CORPORATION. |
