By Carl M. Evans
Atari Basic-Faster and Better
Atari info sequence quantity 1
Carl M. Evans
Read Online or Download Atari BASIC faster and better PDF
Best languages & tools books
Publication by means of Leach, Edmund Ronald
Half three of a accomplished advisor to the language and center non-visual libraries of Embarcadero Delphi XE2; during this half, applications, RTTI, interoperability and multithreading performance are all coated. Adopting an built-in strategy, the booklet covers either more recent and older positive factors along each other.
This ebook deals readers an attractive creation into growing CareKit established functions utilizing the fast language. It begins with the fundamentals and offers a step by step consultant to studying all facets of constructing a CareKit iOS software which can function the foundation for a sufferer care plan. starting Carekit improvement introduces the major modules and ideas of CareKit commencing by way of fitting and development the open resource framework.
Extra info for Atari BASIC faster and better
0: REM RESET WARM START FLAG X=USR(40960) RESTART BASIC This routine examines the LOMEM and MEMLO pointers, and changes them to a new value. Any program that is LOADed or RUN after it, will ignore the reserved block of addresses. The "trick" to this routine is that BASIC only loads a new MEMLO value from the operating system's LOMEM pointer when a NEW command is used. MEMLO is not updated for a LOAD or a RUN. A curious tidbit is that even SYSTEM RESET does not trigger an update of MEMLO under normal conditions.
4. In loops, replace GOSUBs with in-line code - the additional time savings here is due to the fact that BASIC has to add and remove entries from the run time stack each time it encounters a GOSUB. If you eliminate the GOSUB, you also delete the time BASIC would use to keep track of the subroutine. 5. Replace "*,, and "/" operators with equivalent "+" and "-" operators - the multiply and divide routines in Atari BASIC are very slow compared to the addition and subtraction routines. 6. Put multiple statements on a single program line - this is especially effective with loops since BASIC won't have to fetch the next line to continue the loop.
There are some tremendous advantages to this technique. First, if the code is relocatable, we no longer have to worry about where the routine is stored. The starting address of the routine can easily be found by using the ADR command in BASIC. Second, we can store the string packed routine in an ordinary BASIC disk file, which may contain a whole library of routines, for faster and more convenient loading from BASIC. The screen fill routine can be loaded into the string SFILL$ with the following program commands: 100 DIM SFILL$(34) 110 SFILL$(1)=CHR$(104):SFILL$(2)=CHR$(201) 120 SFILL$(3)=CHR$(l) :SFILL$(4)=CHR$(208) ....