The 2 files of sizes mentioned previously might be identical software, having different segmenting, one scheme makes no sense. I'll probably write my own segmentation management utility to solve these issues. But I found a 3rd version of Nadral which so far looks like it has many real differences (in code not necessarily noticed on screen) tho she is on a Bootable disk not file making it harder to compare.
CHEAT MODE unlimited lives. If anyone takes the file version of Nadral here, and changes 2 bytes offset $102A from $65 to $EA and offset $102B from $A6 to $EA, which correspond to program memory addresses $53CA, $53CB : the result is a new file having unlimited lives for both one and two players.
I just struck a rich vein of a8 games possessing hidden cheat modes, Nadral one of them. Back in the 80s some programmer went wild implementing them the same way: unmentioned, unnoticed, unimplemented, until you press spacebar while game is loading. Since emulation today has nearly no loadtime, it's nearly impossible to access these cheat modes without SIO tweaking. It turns out best to make a 2nd changed file renamed with "unlimited lives" or "cheat" in filename, like I just described. Cheers.
Yup, shortening a file by siphoning away only zeros isn't true compression, we could call it "abbreviation" to imply the difference from real compression which has greater results and usually without fragmenting a file's structure.
An example here now of a butchered file is Donald R. Lebeau's "Gauntlet" with the black sky and pink/purple terrain, "contests" and player's manual included. Atarimania's file is abbreviated into hundreds of small segments at 26752 bytes total, I also have the 1 segment original version (2 segments if you include the common 16 bit start address) is 29197 bytes. There's also a small version without the contests and manual. I slowed my emulation down to 15% and measured an increase in time several seconds more needed to load the segmented type of file. Since no real uncompression takes place the time is used by DOS for looping thru segments.
Abbreviated files are a bad idea. I Atari'ed in the 1980s and I never noticed this practice until now. I knew back then it would be a bad move. These shorter files don't retain exact information on how to restore the original, but like you said it is obvious how to in most cases. And, when mission critical zeros are removed, the only time there isn't a glitch or crash is when memory already had zeros in it while loading, like at coldstart. This is ok for disks with multi boot menu etc but if you actually use your Atari for other things, alter memory, then try loading abbrev. file like Gauntlet, a mess occurs. In today's capacity and load time terms, the little space saved ain't worth the aggravation. Not to mention false differences showing up in comparisons of two files which could be functionally the same.
Andreas Koch - 20/11/2015
I am collecting packer, cruncher and compressor programs for the A8. There are approx. a dozen or so of these Bit/Byte compressors and crunchers that remove zeros from a ML file. Most of these programs were coded in the 80s. The packing efficiency of these programs is not very good, but in the 80s many Atarians in Europe used tapes, so making A8 programs a little bit shorter was saving a lot of loading time. Homesoft still uses one of these Bit/Byte compressors with many of his fileversions...
Nowadays we have much better packer programs, like DJ-Packer, Superpacker, Code3-Cruncher, etc. available on the A8 and on the PC. And there are several programs available to reverse or undo the process of these Bit/Byte compressors. Since they create dozens or hundreds of program segments, one can undo this process by filling the gaps with zeros again.
Superpacker on the PC (by TeBe/Tomasz Biela of MadTeam) does this for example. Just load a ML file with it, tag all data segments you want to combine into one segment and then click on "Append" and voila, it creates one big segment, which can then be packed with Exomizer or Inflate if you want.
Ataricom by HiasSoft is another tool which does this, under Win XP (ahem) it works from the command prompt. You load Ataricom and type in the A8 ML file you want to alter, then press Return/Enter. The program will show you all segments of this A8 file and you type "-m" followed by start-segment number and end-segment number (e.g. "1-185") and a new filename and it will merge the segments into one big segment and save everything as a new file.
Guess there are several other programs which can do this, but as of yet I do not know of an A8 program which can fullfill this job...
I've been encountering the handy work of a small compression utility, tho these 2 Nadral files aren't involved, I want to mention it. The compressor removes only strings of zeros larger than some minimum length about maybe 10 or more zeros in a row, does this by means of segmenting the program. For example 1 large segment with a big block of zeros in middle would become a shorter file with 2 segments and no block zeros.
Anyone know the name of this compressor and if it's here on atarimania. Is there a utility to undo this, I doubt because the 2nd file doesn't know which gaps have zeros and which do not. This confounds my comparison utilities and it'll be helpful to temporarily recompress a file to see if it's an exact duplicate of another with zeros removed.
Ultimately I recommend not using this compressor, and, phasing out its "handywork" files in favor of unaltered files especially if the shorter file got majorly fragmented for very little gain. These mangled files might be behind some of the crashes occurring.
Found 2 versions. This download is an executable file 28567 bytes but there's another version 28807 bytes, but I don't know which is the better. I haven't noticed anything changed when playing both files, but a scan of the files reveals at least 31 differences spread evenly, mostly code changes to the game engine probably.
Anyone got any idea which is the better Nadral, spot any changes when playing them ?? ps "Highway Duel" was made by the same two authors in 1984, so that is a Nadral seen in 1984, game Nadral could have beginnings in 1984 or older.
Web searching declares this game was 1985.
Anybody know the date on this game, as compared to Shamus in 1982 ?
The title music is (based upon) "The Entertainer" by Scott Joplin. Look at the screenshot for a game called "Highway Duel" 1984 is that a Nadral trying to cross the road in front of a car? Y'all said the Nadral is half bird (half helicopter).
One of my favourite games for small Atari. Outstanding sound, interesting graphics, and a lot of action makes this game interesting even in these days. I have never finished all levels. It's amazing how much fun you can get from 40KB game. Worth playing
awesome, amazing graphics, very inventive; great contrast of industrial sound and cutesy music! -VNR Press
Well, this looks more like an awful "Shamus" to me than anything else.
I guess Atari didn't want to put their name on a game that had a toilet seat for an enemy, perhaps?
Thorsten Günther - 03/12/2009
Hello! I've just read that this game was indeed sold to Atari Germany, but never published ("ST Computer" issue 6/2001). Is is true that not a single legitimate copy of this game ever existed?
The plot was the following: Nadral, the little flying 'helicopter bird' has to rescue his (similar looking) friend who is hidden behind some doors in the labyrinth. In order to open the doors, you have to find the keys distributed in the labyrinth. When you have opened all doors in a level, you can go to the room with the friend and voila, you can touch him and enter the next level... In the upper levels, the map of the labyrinth is quite complicated :-)
This is one *sinister* game; the title screen has a deceptively jolly bit of ragtime music, but when you start the game a terrifying harsh German voice yells at you, and you're thrown into an inexplicable nightmarish world. Everything's out to get you, time is constantly running out (and an ominous throbbing noise of ever-increasing tempo doesn't let you forget this for a moment), and while the game hard and unforgiving it's not difficult to the point of being frustrating, and the strange visuals and creepy sounds really add atmosphere. Even now I find my heart rate shoots through the roof when I play it!
(Anyone know what the plot was supposed to be?)