Danieljangelich{at}peoplepc. said to Photo at 02-18-03  18:27
 Subject: Re: Fido Attachments/ALL

 Hi Dan,
 
 Da> There are three BBS's still operating within the local dialup that
 Da> I can access Fido. No tell me and it seems to me that before there
 Da> where these transfer programs like x modem, z modem, y modem and what
 Da> ever else check sum protocol program that's out there today. People
 Da> used conversion programs to convert binary programs to ascii files and
 Da> sent them as straight text files, in some cases as an attachment to a
 Da> message in Fido. I've seen it done, I even received a few of the files
 Da> like this. It seems that the images are still sent in the RLE type
 Da> of format so that different type of computers can receive them.

 Yes a few BBS's still exist and gratefully the FIDO NET is carried on
 most of them.  They help keep groups like ours alive, so we want to do
 everything possible to make their job as easy and rewarding as we can.

 Without them, we would be stuck in newsgroups where insults and other
 flames are the norm. Until using the PhotoShop newsgroup, I never had
 a need for the twit filter in my software.   I love a nice civilized
 forum such as we have here where ideas can be exchanged and discussed
 with others from a sensible point of view.

 The schemes you mention above are modem transfer protocols, x-modem did
 64 byte packets I believe, y-modem let the packet size grow to 1024
 byte size, Chuck Foresberg's z-modem added crash recovery to y-modem
 and there was one called j-modem where the packets would continue to
 grow and was the fastest if you had no failures on the line, but
 because it was dealing with such large packets, any error required a
 re-send of a lot of data and in the long run it was slower.  All of
 those are modem protocols and used for one modem to talk to another
 modem. You can still use them when tele-neting if you want.  None of
 them did compression on the data, only transfer.

 PKARC was the standard compression until, I forget the name now, but
 until someone else claimed copyright on the ARC extension.  Phil Katz
 changed his program to create ZIP extensions and placed the name ZIP in
 the public domain.  These were all data compression programs in that
 they used some form of Ziv-Lemple-Welch Run Length Encoding. (RLE)
 Encoding consisted basically of finding all repeating 8 bit characters
 in a data stream and replacing them with a single steering word which
 said how many there were of such a character.  Their largest
 compression came from creating a single file out of many.  By doing
 that they were able to simply remove all the wasted space required at
 the end of each file to fill out the cluster storage size on a disk.

 These still didn't produce a file that was acceptable to send over the
 FIDO net, they did produce a file that was acceptable to send over a
 connection to a BBS where it could be stored and shared by other users.
 This was all withing the confines of the BBS you were, and like many
 may still are using.  The BBS belonged to the FIDO group who set up the
 how's and why for's of FIDO traffic to make it possible for people all
 over the world to communicate with one another in SIG's. (Special
 Interest Groups, ie: Photo )  The methods used to handle that traffic
 used the early Unix protocols as the lowest common denominator, which
 required 1 bit out of every byte for a checksum, leaving only 7 bits,
 enough to get values up to 127, (the ~ character) in the data stream,
 in other words, pure ASCII, not the IBM extended character set.

 Executable programs and their support files use the full 8 bit byte to
 load 8 bit register segments.  Pictures use 8 bit bytes to load color
 and other values.  The Joint Photographer Experts Group, shortened
 to JPG uses the same basic RLE used earlier with an added catch, which
 allows the person creating the JPG file to decide how much he wants the
 compressed file to look like the original.  Greater compression comes
 from saying "OK if it is this close to the original next to it, call
 them the same value,"  compressing the file even more creating a faster
 to transmit picture.  MPEG compression (Motion Picture Experts Group)
 was developed using much of the same principals of JPG, with the added
 ability to look at the proceeding frame of a movie (or video) and say
 the only thing changed was this area here, so the only thing that needs
 added to the file is the data to create the changed area. MPEG, dealing
 with movies required a constant flow of pictures at the receiver, so
 the audio stream accompanying the movie had to be locked to a constant
 bit rate. This audio constant bit rate code is used without the movie
 to create MP3 music file encoding.   The BBS's may have been joined by
 web sites such as Photosig and movie sites like singlereel.com where
 you could store your pictures and videos for show to others.  None of
 this however made anything that could be sent over the FIDO NET.

 The internet is a totally different animal, the software at each end
 is designed to accept data streams at very high rates, has programs
 installed to handle the display of things we could only dream of using
 just a few years ago.  Where my old BBS modem up/download rate might
 have made me very very happy if it achieved 3200 bps my current
 internet connection gives me an upload of 300,000bps and a download of
 1,535,000bps, but that isn't FIDO NET, thats the internet and we can
 thank guys like Chris for providing a connection to the internet so we
 can achieve those transfer speeds.  We are still just sending something
 to a BBS where the sysop is kind enough to package it all together as a
 FIDO acceptable package for sharing with others over the FIDO Network.

 To put an 8 bit file on the FIDO network in the past required the
 sender to change it's format. As FIDO is limited to text only, programs
 such as UUE/D (Unix to Unix Encoding or Decoding) software were used
 to convert to a 7 bit format that could be re-constructed. UUE was the
 most common used, however that required the recipient to have the UUD
 software to reassemble the 8 bit format ZIPed file that was sent via
 z-modem to the BBS.  Many folks used a DBit type program to create a 7
 bit byte file that could be extracted using the dos Debug program,
 Problem was there were many people using other than Microsoft
 computers.  Side note, having dos debug was in my opinion the largest
 reason Microsoft became the dominant player in the PC industry, their
 software could be hacked and coded right out of the DOS package. That
 created a lot of free code for the operating system users and a lot of
 knowledgeable people to work in the blossoming industry.

 Those programs got your data down into a form acceptable to the FIDO
 traffic handlers, but they still didn't get it in the FIDO data stream.
 To do that required one more step, that step was breaking that huge
 file created above into lengths acceptable to all on the FIDO network.
 To do that required using even another program, most common used was
 csplit to break that big file down into text packets of less than 127
 lines each.  Now you had something acceptable to send a picture or
 executable 8 bit byte file over the FIDO network.  All that was left
 to do was to post a message for each one of those split files you had
 created.

 None of this was done by attaching anything to a message, it took a bit
 of work and planning to send that stuff over the Network if and only if
 the moderators deemed it an acceptable use in their echo.

 This simplifies a lot of technical stuff that would take volumes to
 detail, but hopefully gives a good reason why one should send messages
 only in plain text and with no attachments.

 Bobfer (just exceeded 127 lines :-)
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