========
Newsgroups: comp.sys.cbm
Subject: COMP.SYS.CBM: General FAQ, v3.1 Part 4/9
From: brain@mail.msen.com (Jim Brain)
Date: 13 Aug 1996 00:41:53 -0400


X-Posted-By: YPost, version 0.08


Archive-name: cbm-main-faq.3.1.p4
Comp-answers-archive-name: commodore/main-faq/part4
News-answers-archive-name: commodore/main-faq/part4
Comp-sys-cbm-archive-name: main-faq/part4
Version: 3.1
Last-modified: 1996/08/12
             	       	

  ---------------------------------------------------------------------------
  
  Table of Contents (for this file)
  ---------------------------------

   6.  The Online Information Reservoir
   6.1.  How do I download?  What is a transfer protocol?
   6.2.  What is the difference between PETSCII and ASCII?
   6.3.  Where can I find Commodore programs?
   6.4.  What ison, and what do they stand for?
   
  ---------------------------------------------------------------------------


   6.  The Online Information Reservoir
   
   How true this is.  There is information everywhere online, just
   waiting to be accessed and used.at the information
   can be a time consuming process.  
   
   6.1.  How do I download?  What is a transfer protocol?
  
  To transfer files for another computer (another 64 or 128, UNIX, OS/2, 
  DOS, MVS, VMS, Amiga, Atari, or other), you should use a transfer protocol.
  Although it is possible to transfer files by turning on the terminal
  program's capture buffer and receiving the file, this is not very
  reliable and is prone to errors.  When transferring any sizable amount of
  data, one should use some sort of error-correcting file transfer protocol.
  A file transfer protocol splits a file into many pieces, or "packets", and
  send a number of them at a time.  It then waits for an acknowledgement from 
  the receiver that the received received the packets correctly.  At this
  point, the sender send the next batch of packets.  This process is
  repeated until the entore file is transmitted.  Each packet contains
  computed checksums and other error detection bytes to ensure the
  received data is not corrupt.
  
  Below are descriptions for some of the more popular protocols:
   
  C1 (commonly called Punter Protocol)
  
  C1 is a Commodore specific transfer protocol that used to be the
  standard for file transfer.  However, with the increase in IBM-based
  bulleting board, it has been replaced by other protocols.  Most Commodore
  BBS systems still offer C1 (usually called Punter in the list) other BBS systems have support for it.  There is, however, a 
  C1 protocol transfer program for MS-DOS called puntr104.zip.  
  
  KERMIT

  KERMIT is the name of one of the oldest file transfer protocols.  KERMIT
  is unique in that it can encode the file being transmitted so that
  it does not contain any bytes greater than 128 and does not contain any
  special control bytes that terminals use to perform special actions.  As
  such, this protocol is the most robust, but it is also the slowest.  
  A common statement is, "if you can't KERMIT it, you can't get it"

  XMODEM

  XMODEM comes in several varieties.  Standard XMODEM sends files in 128 byte
  packets.  There are two standard error-correction methods with XMODEM
  checksum and CRC.  CRC is the more modern of the two.  There is also a
  version of XMODEM which supports 1K-byte packets.  This version is most
  commonly known as XMODEM-1K, but is sometimes erroneously called YMODEM.

  YMODEM
  
  YMODEM is a "batch" XMODEM protocol, allowing you to transfer multiple
  files in one operation.
  
  ZMODEM

  A new file transfer protocol is ZMODEM.  ZMODEM is theoretically the 
  fastest transfer protocol, but only shows a speed gain over the others
  on noise-free telephone lines.  It achieves this speed increase by only
  replying to the sender about the bad packets.  
  
  Most terminal programs support PUNTER, XMODEM, XMODEM-1K, YMODEM, and 
  KERMIT.  The Kermit terminal program only supports KERMIT, and Novaterm, 
  as of version 9.5, supports ZMODEM receives, but not sends.
   
   
   6.2.  What is the difference between PETSCII and ASCII?
  
  (Note that the Amiga line of computers uses the ISO 8859-1 character
  set, so this does not apply to Amiga computers)
  
  When Commodore designed the PET line of computers, they chose for the 
  character set encoding a special encoding called PETSCII.  This set is
  similar but not the same as the American Standard Code for Information
  Intercahnge (ASCII).  Now, this does not cause any 
  problem when transferring information between or among Commodore
  computers (except the Amiga, which I believe uses ASCII), but causes
  problems when exchanging information with othe computer types.
  
  The obvious solution is for all Commodore users to translate incoming
  information into PETSCII from ASCII when talking to another type of
  computer.  However, this effectively ruins binary files, which have
  no concept of character codes.  Therefore, the rules are:
  
  Do not translate when exchanging binary files with any computer 
  
  Translate all textual information exchanged with non-Commodore computers.
  
  Translate textual information exchanged with Commodore computers only
  if they are translating it as well.
  
  If  a text file you retrieve looks like the uppercase letters should
  be lowercase and vice versa, then the file is in ASCII and needs to
  be converted to PETSCII.
  
   
   6.3.  Where can I find Commodore programs?
   
   Commodore programs are available from a number of sources.  For commercial
   software, please see Section 15.1 for a list of software dealers.  For
   shareware and public domain, you can use FTP 9), electronic
   mail (Section 6.5.2), and bulletin board system in addition to the 
   software dealers to download or buy programs and other software.
  
   
   6.4.  What is a file extension, and what do they stand for?
 
  A file extension is a 1 or more letter suffix appended to the end of a file
  name to indicate the type of file it is.  The extension usually indicates
  the contents of a file.  The list below describes some more common file
  extensions, what they are used for, and how to use the file.
    
  Please note that these file extensions are not Commodore-exclusive.  Many
  computers use file extensions.  Also note that some file extensions
  are cumulative.  IF a file is named "filename.tar.gz", this indicates that
  the file is of type "gz", and the file(s) inside the gz file are of type
  "tar".  To use this file, one would note that both extension are 
  archival extensions.  One would undo the "gz" archival method to restore
  the "filename.tar" archive, then undo the "tar" archival method to restore
  the original file.
  
  Extension:    Meaning:            Notes:
  -----------------------------------------
  .txt          Text File           This file is not compressed, so it needs
                                    no decompression step.  However, the file
                                    may be in either ASCII or PETSCII format,
                                    so a conversion step may be necessary.
                                    Most terminal programs can do this
                                    conversion, and there are stand-alone
                                    programs that do the necessary conversion
                                    also.

  .sda          Self-Dissolving     Just load and run the .sda file to
                Archive             dissolve the archive.  Will dissolve
                                    itself into its constituent files.
                                    C64 and C128 .sda files are not
                                    compatible with each other.

  .sfx          Self-Extracting     Load and run just like a .sda file.
                Archive             The same archive can be extracted on
                                    either a C64 or a C128, memory permitting.

  .arc          ARChive             Use the program arc250.4 or earlier
                                    for the 64 or arc128 for the 128 to
                                    dissolve the archive.  arc128 is available
                                    as part of the CS-DOS package.  Other
                                    de-archive programs may exist.

  .lzh          LHArchive           Use the program lhx in CS-DOS on the
                                    128 to dissolve this archive.  These
                                    are not very common.  This archive
                                    uses the same format as .sfx files,
                                    but is not self-extracting.  It is
                                    a standard format also used by
                                    Amiga (and MS-DOS) computers.  This
                                    format originated on the PC.

  .lnx          Lynx Archive        The above formats all compress files when
                                    storing them; Lynx just stores them.
                                    There are many different versions of
                                    Lynx out there, so good luck dissolving
                                    these.

  .lbr          Library Archive     A format similar to lynx.  Library
                                    dissolving programs exist for both the
                                    64 and 128 to dissolve these.

  .uue          UUEncoded file      UUencoding is a process whereby a binary
                                    file can be converted to an all-text
                                    file, transferable by E-mail.  This
                                    encoded file can later be UUDecoded back
                                    to the original binary file.  Unix
                                    has uuencoding/decoding utilities.
                                    A program "uuxfer" for the
                                    C64 (by Fuzzy Fox) will both uuencode
                                    and uudecode.  Note that the contents of
                                    uue file could be another archived file.

  .uua          UU archive          An extension of uuencoding, a uuarchive
                                    file is a concatenation of one or more
                                    UUEncoded files.  So far as I know, this
                                    was introduced by Craig Bruce in his ACE
                                    shell for the C=128, and the utilities
                                    included with that shell create and
                                    dissolve uuarchives.

  .kar          Kevin's Archive     Another text archive format that seems
                                    to have originated with Craig Bruce,
                                    this is a proscription for concatenating
                                    a series of text files (which can include
                                    uuencoded files) into one file.  More
                                    information can be found in C. Bruce's
                                    documentation for his ace shell.

  x!<file>      ZIPCoded file       ZIPCode is a program that takes an entire
                                    disk and "compacts" it into 4 files that
                                    have a number followed by a '!' and then
                                    a filename.  Also, ZipCode can compress
                                    files, in which case the x is a letter
                                    (a,b,c,d) and there need not be 4 files.
                                    If ZipCode has compressed individual 
                                    files, there will be an "i!" or 
                                    "x!"-prefixed file on the disk that holds
                                    the directory of the file compressed.  To
                                    make things even more confusing, there
                                    are two versions of ZipCode (v1 and v2).
                                    The newer version will accept v1 archives,
                                    but not vice-versa.  Use ZipCode v2 to
                                    unpack such archives.

+ <file>_x.z64  ZIPCoded file       This is just another way of naming the
+                                   above x!<file> ZIPcode files so they can
+                                   be placed on UNIX/DOS machines easier.
+                                   The files mst be renamed to x!<file> 
+                                   before decompression.

  x!!<file>     ZIPCode 6-pack      This is a ZIPCode archive that takes an
                                    entire disk and puts it into 6 files,
                                    each file containing GCS codes and header
                                    info for the tracks.  This is basically
                                    a nybble copier that stores the data it
                                    receives from the disk into files.

  .bco          BCODEd file         BCODing is very similar to UUencoding in
                                    that a binary file is converted into an
                                    all-text format that is 33% larger than
                                    the original.  The difference is that the
                                    BCODE format provides additional
                                    information for error detection and
                                    automatic data segmentation and
                                    reordering.  C-code versions of "bcode"
                                    and "unbcode" are available via FTP and
                                    Commodore versions are prov
                                    ACE-128/64.

  .zip          ZIP archive         Zip is a file format used on IBM
                                    platforms and is created by the PKZip
                                    program that is available for some
                                    platforms.  There are two forms of zip
                                    files that have the same extension.
                                    Both are created by different versions of
                                    PKZip.  The first, version 1.01, can be
                                    dissolved on a 64 by using the program
                                    UNZIP64.  The second, newer format is
                                    version 2.04, which cannot be dissolved by
                                    UNZIP64.  Your best solution when in doubt
                                    is to dissolve the files on another
                                    platform.  For the 128, there is a version
                                    of the UNZIP64 program, called UNZIP128
                                    that has been modified to run in 128 mode.
                                    It is in a file called NZP12817.SFX.  This
                                    archive also has a 64 version.
 
  <file>]x      Compression Kit     x = 4,7,8, cmd, or c(xx) to denote type
                Archive             of media that was compressed.  The files
                                    can be extracted only with The Compression
                                    Kit, from Mad Man Software.
 
  .tar          TAR Archive         UNIX Tape ARchiver.  This program can be
                                    used to archive files as well.  The file
                                    must be decoded using tar.
 
  .Z            Compress archive    Compress is a program on UNIX that will
                                    shrink a single file.  It is usually used
                                    on .tar files in UNIX to reduce their
                                    size.  The file must be decoded by the
                                    uncompress program, available on UNIX, PC,
                                    Mac and other platforms.
                                    Also, a very old version of GNU Zip used
                                    this extension, although the file is not
                                    fully compatible with the compress format.
 
  .gz           GZIP Archive        GZIP is a free program developed by the
                                    Free Software Foundation to freely shrink
                                    their software.  the resulting file must be
                                    decoded by GUNZIP, available on many
                                    platforms, before using.
 
  .taz          Compressed TAR      This is a file that should have the
                                    extension "tar.Z", but has been shortened
                                    for MS-DOS.  Run uncompress, then tar on
                                    this file.
                                    
  .tgz          Gzipped Tar File    This is a file that should have extension
                                    tar.gz, but has been shortened for MS-DOS
                                    Run gzip or similar on the file, then tar.

  .gif          Graphics            This is a compressed graphics format 
                Interchange         created by Compuserve.  To view this file,
|               Format              one must find a GIF viewer program:
+                                   GEOGif.SFX  - Converts GIF to GEOPaint.
+                                   VGIF.SFX    - 64 mode viewer.
+                                   GDS.SFX     - 128 mode viewer.

  .jpeg         Joint               This graphics format can use one of two
                Photographers       compression algorithms.  One, called DPCM
                Expert              (Differential Pulse COde Modulation) 
                Group               retains all of the information in the 
                                    original file, which is usually a picture.
                                    The more common algorithm, called DCT
                                    (Discrete Cosine Transform), relies on the
                                    inability of the human eye to distinguish
                                    among some "throws away" some
                                    information in the file (picture), while
                                    still retaining the essence of the picture.
                                    To view these pictures, one must either
                                    obtain a JPEG veiwer or convert them to
                                    GIF format.
                                     
  .jpg          JPEG                This is an MS-DOS named .jpeg file.
  
  .tiff         Tagged              This is a graphics format used on high
                Image               performance workstations.  To view this
                File                graphics format, you will need to convert
                Format              something else.

  .pcx          IBM Picture         This is graphics format used in DOS on 
                                    IBM machines.  Convert this file to a
                                    GIF file to view.
  
  .pict         Mac PICTure         This is a graphics format used on Apple
                                    Macintosh machines.  Convert this file 
                                    to a GIF file to view.
  
  .d64          1541 Disk Image     This file stores an image of one entire
  .x64                              disk, for use with Commodore emulator
                                    programs.  Several programs exist to 
                                    extract the image onto a disk or place a
                                    disk onto an image.  The only difference
                                    between the .x64 and .d64 file types is an
                                    added 64 byte header on a .x64 file.

  .t64         DataSette Image      This file is analogous to the .d64 file
                                    type, but for tapes.
  
  .p00          PC64 (Emulator)     This file encapsulates a Commodore program
                Program File Image  or data file.  To extract the original 
                                    file, remove the first 26 characters.  In 
                                    addition to .p00, there is .s00 (SEQ), and
                                    .u00 (USR) files, but are very rare.
  
  .bmp          Windows Bitmap      This is a format used for graphics in
                                    Microsoft Windows and OS/2.  Convert this
                                    file to a GIF to view.
  
  .pbm          Portable Bitmap     
  
  .xbm          X bitmap            This is a format used for graphics on the
                                    X windowsing system.  Convert this file
                                    to a GIF to view.
  
  .html         HyperText           This is a WWW hypertext document.  To
                Markup              view this file, you will need a WWW
                Language            browser of some kind.  See Section 6.8 
                                    for more information on WWW.
  
  .doc          Document            This file could be a word processing file
                                    from a program like Word for Windows, 
                                    Wordperfect, or any other word processor.
                                    Also, some text files that contain 
                                    documentation use this extension.
 
  .cvt          GEOS file           GEOS files use a special file format. The
                                    files are called USR files, but they have
                                    special information in the file that
                                    normal files don't, so you cannot just
                                    upload a GEOS file like any SEQ or PRG
                                    file. You can pack all the extra
                                    information and the data into a regular
                                    Commodore SEQ or PRG file with a program
                                    Called Convert.  It has a version 2.5 and
                                    a 3.0.  The files that result from this
                                    conversion have the extension.  The file
                                    must be processed again by Convert before
                                    it can be used with GEOS.

  .N64           64NET file         Since the 64NET system works by allowing
                                    an MS-DOS machine to be used as a large
                                    disk drive, a way was developed to map
                                    CBM filenames into the MS-DOS limitations.
                                    The .N64 filenames indicates such a file.

+ .D71           64NET GEOS File    These are 64NET extensions used to
+ .D81                              emulate a 1571 and 1581 disk drive,
+                                   respectively, under GEOS.

  If the file type indicates an archive, there are many programs available
  that will handle most archival methods. One of these is called Omega-Q II,
  which includes one-stop compression and decompression of many of the above
  archival types.
  
  If you use a host system to download the files from, you may want to
  decompress the files before downloading.  Even though the files will be
  larger to download, the time to decompress them offline will not be a
  factor.  However, those who pay by-the-minute for download time would
  probably want the smallest possible file, which implies decompressing on
  the local machine, except in the case of a UU encoded file.  These files
  are actually bigger in the 'UU' format.

  

-- 
Jim Brain, Embedded System Designer, Brain Innovations, Inc)
j.brain@ieee.org   "Above views DO reflect my employer, since I'm my employer"
Dabbling in WWW, Embedded Systems, VR, Old CBM computers, and Good Times!  -Me-
<a href=http://www.msen.com/~brain/>Jim Brain: BII, VR, and CBM info</a>
