I was a BBS user in the mid 1980s because telephone charges were expensive and Compuserve was not compatible with my teenage budget. Back then I downloaded about three diskettes worth of RLE files, and one or two programs for viewing them.
For those of you not familiar with them, RLE files were simple black and white images usually 256 pixels across and 192 pixels down. The file format was ESC followed by G and H, signaling a screen mode change to “high resolution” graphics. From there the pixel data was encoded as run lengths, using only 7 bit ASCII characters. (That was for modem connection compatibility, allowing for parity checking.)
Compuserve would use them for weather maps or other graphics, and users started adding their own images. Some of these leaked out to BBS systems, where I discovered them.
One of the neat features of the Compuserve VIDTEX software was displaying the images directly, instead of making you open another viewer. CBTerm for the C64 also had this feature. So I started to add this feature to the mTCP Telnet client, figuring that it was a small amount of code and it would be a fun way to get closer to the Compuserve experience.
I was surprised by how little information there is out there on RLEs; it is out there but it is fairly fragmented. The files themselves are also hard to come by; I found one collection of RLE files in addition to my own private collection. So I took some time to write all of this up, including fixing up the noise in my downloaded files and making them available. The write-up and sample images can be found at Rediscovering Compuserve RLE Graphics.
If you have some of these laying around on a diskette somewhere I’d like to hear about it. I think I have the format nailed down and well documented now, but I’m looking to expand the archives of original images. I wasn’t able to find a lot of them which seems wrong; you would think that they are in a SIMTEL style archive somewhere.
There are some example files in the archives mentioned in Image Viewers on CP/M. They aren’t very good, and a few fail to load with your BASIC program or cistopbm
Thanks for the tip! Some of them fail to load because they have bytes at the beginning of the file before the actual RLE header. I’ve cleaned those offending files up and posted all of the RLEs that I found on that CD-ROM on the page.
Well, nearly all. Some of those were not for family audiences. Given the quality nobody was going to mistake them for lost works of art. ;-0
I found this site (only 2 pics) but good description
Computer Art Gallery GO VID-100
Weather Maps GO AWX-4
FBI 10 Most Wanted GO TEN-114
Digitized Photos GO CB-58
Digitized Photos GO CBIG
Digitized Photos GO HHA-88
Digitized Photos GO PCS-155
Digitized Photos GO ARTSIG
Yes, surprisingly few images on the web.
The question is, how do you know that they are original Compuserve files and not later conversions.
Maybe some FBI 10 Most wanted or Weather maps (but could also be GIF or else).
Maybe search for BBS pics (but most are in color).
There are several different RLE formats and several 1-bit formats and many computers used dithering.
Some, early computers have their own formats (some without suffix, some even without header).
For weather pics there is WEFAX.
My personal RLE files still have original file dates from when I downloaded them, as I have the original diskettes and images of the original diskettes. Those are dated from April to August 1987. (I’ve had to modify some of them to clean up extra characters before the start of the image and extra characters after the end, so the file dates on the files I have posted may be newer.)
A lot of the older images will be “signed” with a Compuserve user ID number. You can’t prove provenance on a series of bits, but that’s a good indication they are original images sourced from Compuserve, or at least a Compuserve user. NFTs are a way to prove provenance of digital things, but please we should not go there. Sometimes there is a artist’s name in the image or a BBS name instead. (The Night Shift BBS apparently had a large collection of RLEs.)
There are later images; I posted some of my own recent conversions. I have those there to demonstrate the format is not terrible; it’s just the equivalent of 256x192 black and white dithered images. Generally older images tend to be more line-art or “blocky”, with less dithering.
Thanks for your info! Of course someone’s own files where you know the source are clear. Pics on the web (that are GIF, PNG or else, that should be RLE files might be questionable, same for RLE files).
About 2 years ago, I’ve searched for RLE files (mainly others, mainly color), but I also found the Compuserve files. I was sure having found one from FBI 10 Most Wanted, but yesterday I wasn’t able to find any on the web.
On this PDF at least 5 pics, also showing Christopher Dunn himself (not pictured), pages 17+18. Just printouts but at least the files are named
Maybe there are some sample files in converters (PC and home computers) or file format databases.
Here are software to read these files and some more sample files (last zip) , I think not included in the other zips. http://fileformats.archiveteam.org/wiki/CompuServe_RLE
Sometimes there is a artist’s name in the image or a BBS name instead. (The Night Shift BBS apparently had a large collection of RLEs.)