MAC PDP-6 DECtape File Structure
The MAC system programs, MACDMP, TECO, and MIDAS, assume a certain data structure on DECtapes which they handle. Each DECtape has 1100 blocks of 200 words, numbered 0 through 1077. Block 0 and blocks 1070 through 1077 are not used by the MAC system. Block 100 of each tape contains the File Directory...
Main Author: | |
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Language: | en_US |
Published: |
2004
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Online Access: | http://hdl.handle.net/1721.1/5901 |
Summary: | The MAC system programs, MACDMP, TECO, and MIDAS, assume a certain data structure on DECtapes which they handle. Each DECtape has 1100 blocks of 200 words, numbered 0 through 1077. Block 0 and blocks 1070 through 1077 are not used by the MAC system. Block 100 of each tape contains the File Directory: a 200-word table describing the current contents of blocks 1 through 1067. The data on the tape is organized into files, each file consisting of one or more blocks. Each file has a name and a mode: the name is composed of 2 six-character subnames, and the mode is a two-bit number. The File Directory has space for 27 files. |
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