rave.N2 Dec 2015
XModem-128 had a telltale signature, it padded the last block with the number of included bytes to be kept, so 5 good bytes would be followed by 128 minus 5 5's, or, 10 good bytes then 128 minus 10 10's etc. One example here right now is Lebeau's "Gauntlet", there were $24 bytes in the last block followed by a set of $24's. It was the receiving softwares job to tidy up, which didn't always happen. Once a file got tagged with extra garbage it persisted no matter what protocol became involved. I remember some that used all zeros to pad the last block, but I don't recognize where the $1A1A comes from, that's what this Centipede has = $1A's ... and "Baja Buggies" too.
My estimation is Centipede and Baja Buggies aren't being harmed by the trailing garbage they have now, but Gauntlet is. File loaders write "$24" to memory address $2424 which is in the middle of Gaunlet code or data.
Finding a .com or .xex file size that is a whole multiple of 128 is a strong giveaway the files are more likely to have been padded than naturally be that size.
Andreas Koch1 Dec 2015
A lot of downloaded files from the old BBS`s did have garbage appended to the files, no matter if you used X-Modem, Y-Modem, Z-Modem or certain software like Bobterm and others. Most ML-files that contained such garbage did have various segments with "0000-0000" or "1A1A-1A1A" at the end.
Luckily these redundant segments were most of the time ignored when loaded with a DOS or gamedos - the programs still did run fine. Nevertheless there were some fixer programs for this, like e.g. Filefix 2, Download-Doctor and similar programs. One can even use a packer & linker program (like Superpacker by Bewesoft) to remove these redundant segments.
Its a bit more painful if such garbage has been added to Basic files or pictures/sounds. With Basic files, if the garbage is short and the file still loads okay, one can just LIST the file to diskette, type NEW and then ENTER it again (and then save it again), so all of the redundant stuff gets removed. But its some awkward extra work.
With pictures and music it might be worse, since it can happen that these files have been destroyed by the garbage or the viewer/player programs refuse to load/display or to load/playback these files. For example a compressed Koala / Micro-Illustrator file is destroyed if only one byte of the picture is missing (it cannot be de-compressed anymore). If the picture has garbage added at the end of the file, most viewers will continue loading and thus overwrite the picture on the screen with this garbage.
But as said before, there are some tools to repair such files on the A8, if these tools do not work one must simply try to find alternative file-versions somewhere else. At atarionline.pl they often have various file-versions of one program / XEX file available. Some of these versions do contain the garbage (redundant segments), some do not, some are packed, some are unpacked, etc.
rave.N1 Dec 2015
This file of length 15488 has a corruption, the final 150 characters are appended garbage which should be removed. The repaired version becomes a file 15338 bytes long. This is the best version of Centipede from Atari for model 800, it's the 5200 game imported by Glenn.
rave.N15 Jun 2015
I've seen about 50 versions of Centipede and the 5200 is of course the best. It's the only one that has real fine scrolling of the insect during play. The others including Atari's own 800 version all use blocky characters.
Check out the game "Megalegs". Best homespun clone of centipede and only a 5.5KB program (if you got the 7.5KB version then there's about 2K of zeros in it).
rave.N15 Jun 2015
I've seen about 50 versions of Centipede and the 5200 is of course the best. It's the only one that has real fine scrolling of the insect during play. The others including Atari's own 800 version all use blocky characters.
Check out the game "Megalegs". Best homespun clone of centipede and only a 5.5KB program (if you got the 7.5KB version then there's about 2K of zeros in it).
jcat26 Apr 2011
Best version of one of the best coin-op games ever made. While all the simpleton were playing Space Invaders - the real gamers "got it" with Centipede!
Auntie Pastie9 Apr 2011
This newer "5200" version of Centipede definitely migrated to the 800/XL/XE at some point, because I had it on a late-1980s Atari UK compilation.
Having checked out both this and the obviously inferior original 400/800 version, it's clear that it was the "5200" version I remember playing on my 800XL as a kid.
rexreed20 Oct 2009
This is not the official Atari computer version but a far superior Atari 5200 port. The movement of the centipede and the sounds are as close to the arcade as I think possible. The official version is a clunker.
Heaven16 Aug 2007
best Centipede port...forget the original 800 version done by Atari. This is the version to play with!
