Besides the obvious BASIC programming area (2048 to 40959), there are other good locations available: $02A7 to $02FF (decimal 679 to 767, 89 bytes), $033C to $03FB (decimal 828 to 1019 – the tape cassette buffer – 192 bytes), and, as you mentioned, $C000 to $CFFF (decimal 49152 to 53247, 4096 bytes). There are many places for you to safely place your machine language programs. Like BASIC, machine language programs may be stored on either tape or disk and, once LOADed (by the LOAD command, or via a BASIC loader), it may be called or branched to at anytime by the SYS command. When, in a BASIC program, you see a statement such as 10 SYS XXXX, the program is simply branching to a machine language routine much the same way that a pure BASIC program would branch to a BASIC subroutine via the GOTO or GOSUB command.Ĭommodore's machine language assembler is stored on disk. ![]() The SYS command is used to start a machine language program running. For instance, after a collision has been detected you could branch to a subroutine that would convert the affected sprite's position to its screen position, and then perform a simple PEEK to see what character it hit. However, you can program this option for yourself. It does not offer the option of telling you what character the sprite collided with. The sprite-to-background collision detection byte (53279) is set up to be a "toggle" switch in other words, it registers an off/on condition (collision or no collision). Last, where is there room to insert machine language programs in memory other than C000 - CFFF (49152 - 53247)? ![]() How do they do this? Using Commodore's assembler package, you must load in the machine language program off the disk. Second, I have seen many programs which read: 10 SYS(X). Is there any way to find out what kind of character it hit? ASCII Editor (online tool) did that trick IIRC.I have several questions about the Commodore 64:įirst of all, I know you can check if a sprite has hit a background character by PEEKing (V + 31) when V = 53248. In theory, it could be even faster by turning screen off before printing and turning it on right after (just a few POKEs IIRC), but I doubt it will be useful in this case. Important thing is that just by replacing POKEs with control-chars, program execution is faster. It is perfectly legal (just those lines couldn’t be edited anymore usual way but retyped instead > see “C64 Programmers Reference Guide”, ch2, Introduction). “?” instead “print”, to put more commands in 80-char-per-line limitation. Were not going to do anything difficult yet. In Ascii mode the string 'ABC' would occupy 4 byes, 1 for each character, and a terminating zero: text A B C 0 hex 41 42 43 00 dec 65 66 67 0 In Unicode mode, all characters in memory occupy TWO bytes each, plus two terminating zeroes. ![]() (See also here.) PureBasic has a great feature that helps you with automatic increasing numbers for constants called Enumeration. Pre 5.50 Purebasic would offer two modes: Unicode and Ascii. Last line could be tricky to enter, it should be used with abbreviated (shorted) tolkens – e.g. In PureBasic there are many constants already pre-defined, for PureBasic itself as well as for Windows. Setting j is arbitrary it is equally fast but variable could be useful later (in real program), although prg is bigger for a tiny bit that way. PureBasic is a commercially distributed procedural computer programming language and integrated development environment based on BASIC and developed by Fantaisie Software for Windows, Linux, and macOS.An Amiga version is available, although it has been discontinued and some parts of it are released as open-source. ![]() Now, while Sinclair BASIC would let us place the cursor with a command like PRINT AT INT (RND*22),INT (RND*32) "” :e=ti:print”time:” (e-s)/60 Our Sample Taskįor our initial experiments, we will put the checkerboard graphic at a hundred random places on the screen. That means that to be sure what’s going on you’ll need to do some measurement. This has some occasionally surprising side effects. The core principles, though, are that command interpretation is work and so you want to do as little of it as possible. There’s a bunch of heuristics and rules for getting BASIC code to run slightly faster.
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