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Member Since 29 Sep 2005
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#2980371 Microsoft Basic II as an EXE, does it exist?

Posted by Rybags on Wed Apr 30, 2014 6:18 AM

String array would probably need to be like A$[2]


But really you can do without it.  Doing conversion of existing MS type Basic programs is the main problem.  If starting a fresh program then you can adjust your technique and do a sort of emulation.

#2978975 Atari's Landfill Adventures, I now have the proof it's true.

Posted by Rybags on Sun Apr 27, 2014 11:22 PM

It'll be up as a torrent probably 15 minutes after airing.

#2978307 BASIC Ten-Liners - Contest 2014

Posted by Rybags on Sun Apr 27, 2014 7:07 AM

4. Escape 10


Thanks for the votes.  TBXL version a last-minute thing - actually I think only 1 or 2 statements differ.

I'll have to get started earlier for next year's one, although I had this one practically done a month ago but left it to the last day to add the chset and put the final polish on.


#2978231 Fast Trigonometric Functions?

Posted by Rybags on Sun Apr 27, 2014 1:20 AM

Various things can be done/used.


Lookup tables.  Algorithms for fast (but not real accurate) square-root.


For setting an object trajectory to move towards another, the Bresenham algorithm (used for line draw) could be employed.



In the line-draw, either X or Y is always inc/decremented by 1 each iteration, the other axis is fractional, and the movement decision is made by a simple add or subtract then compare operation.


As an alternative, you could use the delta component from initial line-draw calculation as a table lookup value, have a table with 4, 8, 16, <whatever> sets of H/V velocity values per quadrant.  It wouldn't be an exact path but close.  On-the-fly updates would increase accuracy, plus once two objects are fairly close, the accuracy becomes much less important.

#2977085 Re-using the first bit in color related variables?

Posted by Rybags on Fri Apr 25, 2014 7:26 AM

The lsb is ignored/unused in the hardware registers, so with a RAM shadow you could use the bit for other purposes.


Not as handy as the msb of course since 6502 can easily test it with a single instruction, plus the N flag usually reflects it's state after many operations.


If you wanted to use the msb in assembly, easy enough, you could just adjust your colour value stores, then when copying to the hardware registers, e.g.





#2976925 Why did the Atari 2600 console design change so much

Posted by Rybags on Thu Apr 24, 2014 10:24 PM

The original design is complex and probably cost 3 times or more that of the jr to produce the shell.

Even the 2 moved switches early on would have saved a few bucks.


Also throw in the fact that the original case is over twice as volumous as it needed to be with deletion of inbuilt speakers.


Visual appeal lost out in the end.  The design alone makes the early models collectable and displayable, the jr just looks like any other piece of cheap electronic junk.

#2975720 BASIC Ten-Liners - Contest 2014

Posted by Rybags on Wed Apr 23, 2014 8:52 AM

Here's mine - "Escape 10".


It's a mini, downfeatured version of my Moon Shuttle game - guide your ship through the growing asteroid field and through the gap in the force-field on the right (only to have to repeat it until end of game).


Bonus pickups - (L) for extra life

(I) gives temporary invincibility - grab this then just run over rocks and don't worry about the force-field for the remainder of the level.


Game uses some custom characters, so there's a bit of a delay each time it starts.


Attached File  Esc10.zip   1.95KB   40 downloads


ESC10.TBA - TurboBasic Version

ESC10.BAS - version that runs on normal Atari Basic.

#2973124 Last Ninja on C= Plus4

Posted by Rybags on Sat Apr 19, 2014 8:37 PM


All the graphics are multicolour, ie 160x200 effective resolution including the ninja.

Just one enemy appears, graphics are the same as the ninja for him.

I would think they're using multicolour bitmap mode, this allows 2 fixed colours and 2 colours controlled by cell attributes.

#2972521 Is anyone else interested in a better Donkey Kong Jr.?

Posted by Rybags on Sat Apr 19, 2014 12:01 AM

The music + effects from the computer version are pretty good, why not just borrow those?

#2971913 where was the 7800 released?

Posted by Rybags on Fri Apr 18, 2014 8:59 AM

I'm not sure what the original bundle arrangement was - probably nothing.


32in1  - didn't that also come with 2600jr at some stage?


I do remember later in it's life the 2600jr was about $39 here.  7800 didn't exactly do great sales, in the day I can't recall knowing anybody who bought one.  I got my first one probably under 10 years ago.


In the last days of Atari, some gear did go for low prices and in bundled deals.  I remember seeing XEGS well under $200.  One the Lynx came out though, 7800 went off the radar.  Not that Lynx did great things here.  Jaguar was practically unknown.

#2971707 atari800win access host files from DOS?

Posted by Rybags on Thu Apr 17, 2014 10:21 PM

H: is still there but DOS 2.x generally doesn't handle devices other than D: all that well.


If you want to copy files, generally it's a case of using the full name rather than wildcards.  Additional to that, long filenames won't be handled well.

But a lot of stuff like copy, rename, delete doesn't matter much anyway since you can more easily just do it from Windows.

Also, the emulator creates an environment such that the directory is like a DOS 2.x disk, so IIRC you'll be limited to the first 64 files located in many cases.

#2970358 BASIC turns 50

Posted by Rybags on Wed Apr 16, 2014 8:44 AM

I never agreed with the whining about GOTO.

If you have a program that's a finite process and does stuff with a bunch of data records, then fine - even with a primitive language you can get away with just loops + subroutines.

In a game, at the very least you usually have a DO / UNTIL <never> condition.


In our old clunky Basic on many old computers, it was often the case that you had to put the stuff you wanted to be fast at the start of the program.  Not just Atari, but many other systems as well.  So at the least, you had at least one unconditional branch at the start.

#2969492 Which XEGS roms do I need for Altirra?

Posted by Rybags on Tue Apr 15, 2014 2:58 AM

It's generally easier to just play the game from cart image.

Emulating the XEGS is more for the sake of completeness and alternate config testing than providing the "convenience" of a built-in game.

#2969462 Lemon 64 down?

Posted by Rybags on Tue Apr 15, 2014 12:19 AM

There's other C64 game database sites around, for me the main use of Lemon is the forums.

#2969461 Commodore 64 emulator disk image (.d64) help need

Posted by Rybags on Tue Apr 15, 2014 12:18 AM

WinVICe is the emulator of choice for the C64, and it does their other 8-bit machines as well.


.D64 definately is writable, maybe it's just a MESS limitation that you're experiencing.


MESS is generally a pain to use compared to dedicated emulators, the few Meg that each dedicated emulator takes up is a small price to pay for the extra ease of use.