Sponsored Content
Top Forums UNIX for Dummies Questions & Answers Not quite related to Unix but CP/M file structure... Post 302149063 by Legend986 on Tuesday 4th of December 2007 07:37:01 PM
Old 12-04-2007
Not quite related to Unix but CP/M file structure...

I'm not sure where to post this but I'm having some trouble with the directories in CP/M... I'm sorry about the length but I'm totally confused... I've seen that the directory entry in CP/M contains the following:

1 byte User Code
8 bytes Filename
3 bytes File extension
1 byte Extension
2 bytes reserved
16 bytes Disk block numbers

First of all, what are those 2 bytes reserved for? Will that be used if the file occupies a large number of blocks thus supporting as an extension to that 1 byte "Extension field"? Secondly I don't understand how this works... Is it stored something like this?

1 | FileA | exe | 1 | --- | 1 2 3 4 5 6 7 8 9 ... 16 |
1 | FileA | exe | 2 | --- | 17 18 19 ...............33 |
...
...

I read that the Extension field is used to keep track of the order of the storage as to which blocks come first. The disk block numbers point to blocks of size 1 KB... So what is the largest disk that the CP/M could support anyways? Was it just a floppy disk or something? What happens if I choose a block size more than 1KB say 512 KB or something? I did a rough calculation messing with other parameters and got some 2048 GB which I think is just too huge to be true... I could've even made the block size as 1 MB but what is the limiting factor here?

Last edited by Legend986; 12-04-2007 at 08:42 PM..
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Unix/Linux Directory Structure

Does anyone know of a good Internet source that explains the directory structure of Unix/Linux?? Thanks Gregg (2 Replies)
Discussion started by: gdboling
2 Replies

2. UNIX for Dummies Questions & Answers

Unix Related

well through my 6 months education i know some unix os but i can't find one for my p3 via board can any one tell me where to find such please replay as email or private msg and thanks (3 Replies)
Discussion started by: JaMaL
3 Replies

3. UNIX for Dummies Questions & Answers

What are some benefits of the UNIX hierarchical file structure?

What are some benefits of the UNIX hierarchical file structure? I am new to UNIX and researching some information about it for a class so please help if you can. Thanks. (1 Reply)
Discussion started by: 88923JJJSDK
1 Replies

4. Forum Support Area for Unregistered Users & Account Problems

How to post a new thread (Regarding Unix related doubts) in Unix Forums

How to post a new thread (Regarding Unix related doubts) in Unix Forums. I registered my id but I am unable to post my Questions to Forum. Thanks & Regards, indusri (1 Reply)
Discussion started by: indusri
1 Replies

5. Programming

compare XML/flat file with UNIX file system structure

Before i start doing something, I wanted to know whether the approach to compare XML file with UNIX file system structure. I have a pre-configured file(contains a list of paths to executables) and i need to check against the UNIX directory structure. what are the various approches should i use ? I... (6 Replies)
Discussion started by: shafi2all
6 Replies

6. Fedora

How is OS X related to unix

Ok, I gotta ask this question, I have just begun fundamentals of UNIX in college and have learned or heard that Mac's OS-X is a linux based os! Does this mean that unix shell commands work in OS-X? I have no experience with os-x yet. I know it's a stupid question but I gotta know! (10 Replies)
Discussion started by: boarder428
10 Replies

7. UNIX for Advanced & Expert Users

Unix commands Related to

Hi all, Does unix has any commands for creating BLOB and CLOB objects. Please forward me any sites or samples (2 Replies)
Discussion started by: rajeshorpu
2 Replies

8. Shell Programming and Scripting

Getting the Folder Structure in Unix

Hi All, I have a compute box and I want to tar directory structure under a directory and then Deploy/untar it in a new compute box so that the directory structure will be exactly the same. I do not want any of the file to be extracted and deployed but instead only the directory structure. ... (2 Replies)
Discussion started by: filter
2 Replies

9. Shell Programming and Scripting

need downloading related help...but its not related to unix

Hi All, I am trying to dowmload the zip file "zkManageCustomers.zip " but i dont have access. Can anyone help me to download this file See the below link- http://www.ibm.com/developerworks/opensource/library/wa-aj-open/index.html?ca=drs- Please help me as early as... (1 Reply)
Discussion started by: aish11
1 Replies

10. Ubuntu

Query related to conversion of segy file and .su files using Seismic Unix

hi M using ubuntu 11.04....and has installed Seismic Unix on it.... I want to process some unprocessed segy data using Seismic Unix.... i have converted .segy file to .su using segyread tape=file1.seg verbose=1 endian=0 | segyclean > smallfile.su and got 3 files -smallfile.su... (0 Replies)
Discussion started by: Ankita Singla
0 Replies
MTBL_INFO(1)															      MTBL_INFO(1)

NAME
mtbl_info - display information about an MTBL file SYNOPSIS
mtbl_info FILE [FILE]... DESCRIPTION
mtbl_info(1) displays the following information about the MTBL files specified on the command line. file name -- the name of the MTBL file. file size -- the total size of the MTBL file, in bytes. index bytes -- the total number of bytes and proportion of the total file size consumed by the index. data block bytes -- the total number of bytes and proportion of the total file size consumed by data blocks. data block size -- the maximum size of an uncompressed data block. data block count -- the total number of data blocks. entry count -- the total number of key-value entries. key bytes -- the total number of bytes that all keys in the file would occupy if stored end-to-end in a byte array with no delimiters. value bytes -- the total number of bytes that all values in the file would occupy if stored end-to-end in a byte array with no delimiters. compression algorithm -- the algorithm used to compress data blocks. Possible values are "none", "snappy" and "zlib". compactness -- a rough metric comparing the total number of bytes in the key-value entries with the total size of the MTBL file. It is calculated as (file size) / (key bytes + value bytes), and thus takes into account the gains of data block compression and prefix key compression against the overhead of the index, trailer, and data block offset arrays. 05/29/2012 MTBL_INFO(1)
All times are GMT -4. The time now is 06:00 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy