 music |
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record I/O
summary
This subchapter looks at record I/O.
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stub section
This subchapter is a stub section. It will be filled in with instructional material later. For now it serves the purpose of a place holder for the order of instruction.
Professors are invited to give feedback on both the proposed contents and the propsed order of this text book. Send commentary to Milo, PO Box 1361, Tustin, California, 92781, USA.
record input/output
This subchapter looks at record input and output.
Pascal eof(x) — Pascal standard function that returns true if the end of file or end of data has been reached; otherwise returns false.
Ada
“42/2 The predefined environment of the language provides for input-output and other capabilities by means of standard library packages. Input-output is supported for values of user-defined as well as of predefined types. Standard means of representing values in display form are also provided.” —:Ada-Europe’s Ada Reference Manual: Introduction: Language Summary See legal information
“2 Finally, a predefined environment of standard packages is provided, including facilities for, among others, input-output, string manipulation, numeric elementary functions, and random number generation.” —:Ada-Europe’s Ada Reference Manual: Section 1: General See legal information
assembly language instructions
Input/Output (I/O) instructions are used to input data from peripherals, output data to peripherals, or read/write input/output controls. Early computers used special hardware to handle I/O devices. The trend in modern computers is to map I/O devices in memory, allowing the direct use of any instruction that operates on memory for handling I/O.
- IN Input; MIX; initiate transfer of information from the input device specified into consecutive locations starting with M, block size implied by unit
- OUT Output; MIX; initiate transfer of information from consecutive locations starting with M to the output device specified, block size implied by unit
- IOC Input-Output Control; MIX; initiate I/O control operation to be performed by designated device
- JRED Jump Ready; MIX; Jump if specified unit is ready (completed previous IN, OUT, or IOC operation); if jump occurs, J-register loaded with the address of the instruction which would have been next if the jump had not been taken
- JBUS Jump Busy; MIX; Jump if specified unit is not ready (not yet completed previous IN, OUT, or IOC operation); if jump occurs, J-register loaded with the address of the instruction which would have been next if the jump had not been taken
MIX devices
Information on the devices for the hypothetical MIX processor’s input/output instructions.
| unit number | peripheral | block size | control |
|---|---|---|---|
| t | Tape unit no. i (0  i 7) | 100 words | M=0, tape rewound; M < 0, skip back M records; M > 0, skip forward M records |
| d | Disk or drum unit no. d (8 d 15) | 100 words | position device according to X-register (extension) |
| 16 | Card reader | 16 words | |
| 17 | Card punch | 16 words | |
| 18 | Printer | 24 words | IOC 0(18) skips printer to top of following page |
| 19 | Typewriter and paper tape | 14 words | paper tape reader: rewind tape |
See also Input/Output Instructions in Assembly Language
free music player coding example
Coding example: I am making heavily documented and explained open source code for a method to play music for free — almost any song, no subscription fees, no download costs, no advertisements, all completely legal. This is done by building a front-end to YouTube (which checks the copyright permissions for you).
View music player in action: www.musicinpublic.com/.
Create your own copy from the original source code/ (presented for learning programming).
computers using 
and served using 
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