29 Jun
2007
29 Jun
'07
7:13 a.m.
At 09:20 PM 6/28/2007, Ethan Dicks wrote:
Hmm... I know that RLE pictures existed (before GIF),
and were
monochrome, not color, but I don't recall experiencing them in 1982.
I'm positive that my BASIC terminal program knew nothing about them.
Perhaps the VidTex client I tested knew what to do with them, but I
don't remember ever viewing any on a C-64.
Does anyone have any RLE files or know more about when and in what
context they appeared (besides, obviously, just "on CIS").
Before researching, my memory was that they were first used
for CIS weather maps.
In my CCC archive, I found a '98 message between Merch and I that
mentioned RLE files stored in his Tandy 600 archive, so I bet the Model 100
and CoCo people have archives, as they certainly have decoders.
The Wikipedia entry for Compuserve isn't specific about when they
released RLE. The run-length-encoding entry doesn't even mention it.
Maybe I'll put it on my to-do list. For perspective, "medium" res
was 128 x 96, "high" was 256 x 192.
I was surprised to see that the O'Reilly Encyclopedia of Graphics File Formats
(of which I was contributor and editor to the second edition) didn't even mention
CIS RLE files. RLE is a common technique, so there's a chapter about RLE
in general. You can certainly google a number of other references to
RLE-based file formats from that decade (Utah Raster Toolkit, Wavefront .rla, etc.).
GIF dates to 1987. I would guess RLE was at least three years older.
- John
29 Jun
29 Jun
2:11 p.m.
New subject: Dialling up in 1982 (was Re: old modems (was Telephony switches))
RLE4 and RLE8 are mentioned on a page about bitmaps. Never heard about RLE (0/1?) until
now.
GIF can't be too old as it uses LZW compression which IIRC was created by Welch in the
early to mid 80's, based on the original algorithm by Lempel and Ziv. (I looked up
compression techniques, studied and created by own LZW compression/decompression routines
in late 2005 so I believe thats all correct)
Regards,
Andrew B
aliensrcooluk at yahoo.co.uk
John Foust <jfoust at threedee.com> wrote: At 09:20 PM 6/28/2007, Ethan Dicks
wrote:
Hmm... I know that RLE pictures existed (before GIF),
and were
monochrome, not color, but I don't recall experiencing them in 1982.
I'm positive that my BASIC terminal program knew nothing about them.
Perhaps the VidTex client I tested knew what to do with them, but I
don't remember ever viewing any on a C-64.
Does anyone have any RLE files or know more about when and in what
context they appeared (besides, obviously, just "on CIS").
Before researching, my memory was that they were first used
for CIS weather maps.
In my CCC archive, I found a '98 message between Merch and I that
mentioned RLE files stored in his Tandy 600 archive, so I bet the Model 100
and CoCo people have archives, as they certainly have decoders.
The Wikipedia entry for Compuserve isn't specific about when they
released RLE. The run-length-encoding entry doesn't even mention it.
Maybe I'll put it on my to-do list. For perspective, "medium" res
was 128 x 96, "high" was 256 x 192.
I was surprised to see that the O'Reilly Encyclopedia of Graphics File Formats
(of which I was contributor and editor to the second edition) didn't even mention
CIS RLE files. RLE is a common technique, so there's a chapter about RLE
in general. You can certainly google a number of other references to
RLE-based file formats from that decade (Utah Raster Toolkit, Wavefront .rla, etc.).
GIF dates to 1987. I would guess RLE was at least three years older.
- John
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