Cell Drive. The increase in capacity achieved by replacing a 2314 or a 2321 with a 3330 depends upon the block size chosen for the data on the 3330. For example, if the 2314 full track block size of 1294 bytes is maintained for a given data set on the 3330 to avoid
programming changes, the 3330 yields a 91J increase in full pack
capacity (almost twice the capacity). However, reblocking to a full
track on the 3330, 13,030 bytes, yields a 242J full pack capacity
increase. If there is not enough processor storage available to
allocate I/O areas of 13,030 bytes, lowering the 3330 block size used
to half a 3330 track yields a
239~increase in full pack capacity.
If a 2321 is replaced by a 3330, six full track blocks of data
Characteristics 3330 2314 2321
Capacity in bytes truncated to the nearest thousand
(full track records)
Pack or cell 100,018,000 29" 1 7 6 , 0 0 0 39,200,000 Facility or Data Cell Drive
2 drives/cells 200,036,000 58,352,000 78,400,000 4 drives/cells 400,073,000 116,704,,000 156,800,000 6 drives/cells 600,109,000 175,056,000 235,200,000 8 drives/cells 800,146,000 233,408,000 313,600,000
10 cells
- -
392,,000.000 Number of recording surfaces(recorded tracks per pack)
mechanism is self-adjusting and automatically rises in increments as the stack of paper mounts. This insures that the stacker mechanism is always the same distance above the top of the stack of forms. The rate of rise during each increment is determined by the setting of the stacker rate knob, which can be adjusted by the operator to produce the best condition for the thickness of the forms being stacked. The stacker also can be raised or lowered manually.
When forms are inserted, the printer platen automatically positions itself close to the train cartridge in accordance with the thickness of the forms. Thus, correct clearance between the platen and the cartridge is achieved without operator intervention. Because of its automatic forms thickness sensing, the 3211 is sensitive to forms with a different degree of thickness at each edge. (For forms limitations, see Form-Design Considerations-System Printers, GA24-3488.)
Forms control paper carriage tape loading and unloading by the operator is eliminated by implementation of a tapeless carriage feature for the 3211. Forms spacing and skipping are controlled by a program-loaded forms control buffer (FCB) contained in the 3811 control unit.
The FCB contains 180 storage positions, each of which corresponds to a print line, that is, a single space of the carriage. Thus, forms up to 22.5 inches in length can be accommodated at 8 lines per inch spacing (or 24 inches at 6 lines per inch). Up to twelve channel codes
(1-12), corresponding to the twelve channel positions of the paper carriage tape used on a 1403 Printer, can be stored in the appropriate buffer line positions to control carriage skipping. The FCB can be considered to contain a storage image of a carriage control tape.
A carriage control address register is used to address the FCB and maintain correct line position with respect to the form. This register is incremented as space and skip commands are issued that cause the form to advance. When a SKIP TO CHANNEL command is executed, the carriage control address register is incremented and the form moves until the channel specified is sensed in a line position in buffer storage. If the requested channel number is not found in the buffer, forms movement stops after address position 1 (line 1) has been sensed twice. This prevents runaway forms skipping.
A flag in a buffer storage line position is used to indicate the last line of the form for forms shorter than 180 lines. A flag bit is also used in the first buffer storage position to indicate six or eight lines per inch spacing. The FeB is loaded with the desired forms spacing characters via a LOAD FCB command issued by a program. An error indication is given if an end-of-page flag is not present or if an invalid carriage code is loaded.
Serviceability features, in addition to those provided for the 1403 Printer, are incorporated into the design of the 3211. The fact that a 3811 control unit controls only one 3211 Printer, instead of multiple devices, permits offline repair of the malfunctioning printer or control unit only, without the necessity of removing other
operational units from the system.
The 3811 control unit presents six bytes of sense information to identify printer and control unit malfunctions instead of only one, as is provided for the 1403. Certain errors (such as a parity check in the print line buffer) that might be corrected by programmed retry of the print operation are identified in the sense bytes, and carriage motion is suppressed. This permits error recovery without operator intervention if the retry is successful. The additional status data presented can be stored for later analysis and should help speed the diagnosis of hardware malfunctions.
SECTION 30: PROGRAMMING SYSTEMS SUPPORT
30:05 TRENDS IN DATA PROCESSING AND PROGRAMMING SYSTEMS
--
----The Model 165 and its programming systems support have been designed to operate in the data processing environment that has been emerging since introduction of System/360.
52
Significant trends are the following:
• Growth toward more multiprogramming to improve system throughput.
Multiprogramming also permits the user to install new applications, such as small teleprocessing inquiry, graphics, or time-sharing applications, that would not otherwise justify a dedicated system.
Multiprogramming support also has encouraged the growth of new computer environments, as indicated by the items that follow.
• Growth of integrated emulation, that is, concurrent native and
emulation mode processing on one system. The execution of emulators under operating system control improves system throughput because emulators can use control program facilities (stacked job execution, data management functions, etc.) and because native mode and
emulator jobs can be scheduled to operate concurrently to utilize available system resources efficiently. The use of integrated emulators eliminates most reprogramming and eases transition from one system to another, permitting the user to expend his efforts extending and adding applications.
• Greater use of high-level languages, such as COBOL, FORTRAN, and PL/I, for applications programming. The cost of programming has been increasing while the cost of computing hardware has been decreasing. More productive use of programmers can be achieved by the use of high-level languages. Improvements to compile times and to the size and execution speed of code produced by high-level language translators have been made and continue to be made. The support of many more functions within high-level languages also has increased their use, and the growth of interactive computing has stimulated the addition of even more facilities.
• Growth of teleprocessing applications such as remote inquiry, message switching, data collection, and management information systems. The ability of System/360 and System/370 to handle teleprocessing and batch processing in one system eliminates the necessity of dedicated special purpose systems.
• Growth of remote computinq activities, such as remote job entry and interactive computing-(or time-sharing) in both a nondedicated and dedicated envirolli"ent. Remote computing offers (1) fast
turnaround for ba~ch work submitted from remote locations, (2) remote user access to the large computing facilities and data base available at the central installation, and (3) interactive problem solving on a regular or a nonscheduled basis for personnel in locations remote from the central computer. In-house interactive computing is growing also as users attempt to use programmer time more efficiently.
• Growth toward large, online data base systems. The growth in the marketplace of remote computing, tLme sharing, and real-time applications necessitates the instant availability of more and more data. High-capacity, fast, reliable direct access devices are required for this type of computing environment.