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-rw-r--r--doc/fileformat.txt14
1 files changed, 8 insertions, 6 deletions
diff --git a/doc/fileformat.txt b/doc/fileformat.txt
index 8356df5..836e04d 100644
--- a/doc/fileformat.txt
+++ b/doc/fileformat.txt
@@ -70,11 +70,13 @@ The differences are:
the file.
- ARC and ALF both store the compressed and uncompressed file lengths
- as 32-bit unsigned integers... but the Atari can't deal with really
- large files. From examining the disassembled code of UNALF14.COM,
- it looks like the highest byte isn't even looked at, meaning the
- maximum size for a single file is 16MB. I have actually tested the
- Atari ALF and UNALF programs with an emulator (and emulated hard
- drive) with a file of 200KB in size, and it worked fine.
+ as 32-bit unsigned integers, but in ALF only 24 bits are actually
+ used. From examining the disassembled code of DZ.COM, it looks like
+ the highest byte isn't even looked at, meaning the maximum size for
+ a single file is 16MB. I have verified this by compressing large
+ files with LZ.COM, running in an emulator with 'turbo' enabled. A
+ 16MB file (16777216 bytes) causes LZ.COM to go into an infinite
+ loop, but a 16777215 byte files will compress successfully, and
+ decompress correctly with DZ.COM.
Author: B. Watson (urchlay@slackware.uk)