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Technology Stocks : Ampex Corporation (AEXCA) -- Ignore unavailable to you. Want to Upgrade?

To: Richard Esmond who wrote (3840)	11/17/1998 4:39:00 PM
From: Richard Esmond	Read Replies (1) \| Respond to of 17679

Trying to be clearer! I just re-read my own post and my first statement is not very clear. By 'I don't think you are', I ment to disagree with your statement that you were probably not understanding the issue. I think you do understand the issue. And, the frustration that I was refferring to is at StorageTek, not Ampex. These problems should not be difficult to solve, if you have an interest. Sorry.

To: Richard Esmond who wrote (3840)	11/17/1998 4:41:00 PM
From: Hal Campbell	Respond to of 17679

Best of luck in your efforts, RE ( alot of acronyms hereabouts). I am sure others on this board who have vastly greater technical knowledge than I will have useful comments.The following might interest you. AXC's drives are very expensive but also very good and, on mammoth levels of storage, very cost effective. Also unique in many respects. With quad density they will hold 660 partionable gigs per tape. From Ampex homepage DST white paper on video storage applications (though info is out of date - they have improved performance and added a model- the tape format is described).... The recording format used in DST drives has several unique characteristics, but most notable are the use of partitioning, system zones and linear tracks. Tape partitioning allows for an individual cartridge to be divided into defined segments for user data. Each segment or partition can be treated as an independent volume and can be updated without invalidating data in other partitions. Partitions are user definable, although a tape requires at least one partition. The number of partitions will depend on the application. Partitioning allows for significant improvements in tape space management by more efficiently utilizing all of the capacity on a single cartridge. In other tape formats capacity is wasted because cartridges are treated as single volumes. In these environments users are forced into append-only operations for file updates. Insert writes are not possible without corrupting the data on files written further down the tape. Consequently, only a very small percentage of the overall tape capacity is used because it becomes too cumbersome to search to the end of data each time a cartridge is exchanged and a file is written to tape. By incorporating muiple partitions on a single cartridge, updates can be made to independent volumes located anywhere on the tape and search time is reduced by the ability to perform high speed positioning to the partition. Systems zones are specific areas along the tape where the media can be safely mounted or dismounted. System zones can save a significant amount of time by eliminating the need to rewind to the beginning of tape prior to a cartridge exchange and by not always having to search from the beginning of tape to a file. System zones also contain volume format information making it easier to position to data in a partition. The number of system zones can also be set by the user. Systems zones and partitions are defined at the time the tape is formatted. Linear tracks are recorded along the edge of the tape in addition to the helical tracks. These tracks are automatically recorded as the data is written and provide the ability to address either file number, data blocks or a specific byte within a user file. This feature allows for high speed search to any point in the recorded data at up to 800 megabytes per second. The DST tape drive allows the user to set the application block size for any file or file segment when writing. Variable length recording can be achieved in an application by using a block size of one. The block size range can be one (byte stream mode) or an even number of bytes between 80 and a maximum of 1,199,840 bytes which is the physical block size recorded on tape, i.e. the minimum unit in which data can be written or read. The ideal data block sizes are those that divide into the physical block to maximize tape capacity and avoid spanning physical block boundaries. In addition to smoothing out the streaming of data to and from tape, the buffer also handles all the conversions of data blocks to and from physical blocks. Ampex DST drives employ three levels of Reed-Solomon error correction. The data is shuffled across tracks that constitute a physical block and interleaved within the track so that each byte has maximum physical separation from related bytes. Two levels of error correction are used during write verification, leaving the third level error correction capability for future read operations if needed. Any time the second level is unable to correct the error during writes, the block is marked and the data is written further down the tape without interrupting the tape motion. DST tape drive data transfer rates, search speeds and capacity are stated with full error correction applied. DST Platform Support and Software Control Ampex DST software allows for the integration of DST tape drives and libraries on many UNIX platforms including those from Sun Microsystems (Solaris), Hewlett-Packard (HP-UX), IBM (AIX), Silicon Graphics (IRIX) and Digital (Digital UNIX) via a 16-bit fast SCSI-2 interface. Ampex DST software was designed with a combination of both standard UNIX and Ampex interfaces. This provides support for the advanced operational features found in DST storage devices and to allow integration with legacy, i.e. older, applications previously developed for more conventional tape drives. Ampex software provides a wide range of flexibility for developers and users offering the ability to control tape drives and libraries through a combination of management utilities, application programming interfaces (APIs) and platform specific device drivers. Ampex DST Product Line DST 310 and DST 312 Double Density Tape Drives Support three cartridge sizes with uncompressed capacities of 25, 75 and 165 GB or 50, 150 and 330 GB. 15 MB/second uncompressed data transfer rate (native read/write speed) and 800 MB/second or 1.6 GB/second data search speed. Smart DD-2 tape format supporting volume partitioning and multiple system zones. Three levels of Reed-Solomon EC with read after write verification and automatic rewrite capability. DST 410 1.2 TB and DST 412 2.4 TB Double Density Automated Cartridge Libraries Less than 8 sq. ft. floor space requirement or available in standard 19" rack mount configuration. Supports three cartridge sizes with uncompressed capacities of 25, 75 and 165 GB or 50, 150 and 330 GB. 15 MB/second uncompressed data transfer rate (native read/write speed) and 800 MB/second or 1.6 GB/second data search speed. Smart DD-2 tape format supporting volume partitioning and multiple system zones. Three levels of Reed-Solomon EC with read after write verification and automatic rewrite capability. DST 810 6.4 TB and DST 812 12.8 TB Double Density Automated Cartridge Libraries Less than 21 sq. ft. floor space requirement Configurable with up to four DST tape drives. High performance tape robotics capable of 600 cartridge exchanges per hour. 15 MB/second uncompressed data transfer rate (native read/write speed) and 800 MB/second or 1.6 GB/second data search speed. Smart DD-2 tape format supporting volume partitioning and multiple system zones. Three levels of Reed-Solomon EC with read after write verification and automatic rewrite capability