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https://github.com/dlidstrom/hp48page
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43 lines
1.8 KiB
HTML
43 lines
1.8 KiB
HTML
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<HTML>
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<HEAD>
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<TITLE>HP48 Assembly-Programming</TITLE>
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<BODY BGCOLOR="#FFFFFF">
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</HEAD>
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<BODY>
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<H1>Entries</H1>
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Take a look at the sorted <A HREF="ent_srt.zip">entries</A>
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to find most of the entries you would ever need. I keep it printed
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and refer to it all the time.
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<P>
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There are some things you will have to know in order to make use
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of this document. Lets take a look at an example:
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<PRE>
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*****************************************************************
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=PUSH# EQU #03F5D * Stack: ( --> # )
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* Entry: R0[A]=num P=0 HEX RPLRAM
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* Exit: P=0 HEX RPLCPU A[A]=->bintob
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* Alters: A[15-5] B[15-5] C D[15-5] ST0 ST10
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* Stack: 3
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*****************************************************************
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</PRE>
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The name of the entry is =PUSH#, this is what you would type in
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your program. You would probably call it with GOSBVL. An entry
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that restarts rpl should be called with GOVLNG. <BR>
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The address is #03F5D. You shouldn't have to worry about this.<BR>
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The stack diagram ( --> # ) shows what happens on the stack. Here
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the symbol # is used to indicate that a bint is pushed on the stack.<BR>
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On entry, that is when you call the subroutine, a few conditions must
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be met. R0[A] contains the number, P must be 0, the cpu must be in
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HEXMODE, and the pointers must have been saved (RPLRAM=saved,
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RPLCPU=restored).<BR>
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On exit, when the program continues after the subroutine, P is 0,
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cpu is in HEXMODE, the pointers are restored, A[A] contains the address
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to the pushed bint. <BR>
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When this subroutine is executed, it may alter a few registers. In this
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case the nibbles 15-5 in A, B, and D as well as the entire C are
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altered. This means you shouldn't have important data in these places as
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they will be lost. Status flags 0 and 10 and three stack
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levels on the return stack are also used.
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</BODY>
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</HTML>
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