Unfinished Bitness

In the beginning…

When I started this learning 6502 assembly project, I wanted to create pure assembly code without the use of macros or routine libraries.   Working without routines can be done, but it creates a lot more work.  So I caved in and decided re-useable code was a must have.  In doing so I created several files that make up my library of routines.  In this post I will break down the assembly routines I have written, and in the case of string to integer functions, adapted into my library.  As I learn I’m determined to keep everything written by myself, unless it’s just over my head like the string to integer functions.  I’m hoping that was the only exception.

The Library

I’m just calling my A8 Library.  Currently it is comprised of four (4) files.  There is a definitions file, a general functions file, a string macros file, and a string functions file.  Each is in SAVE format, not LIST, so they can be included in program source.  They are:

• A8DEFS.LIB: Definitions, such as names for memory locations, etc.
• A8FUNCS.LIB: Functions (general), such as position cursor, etc.
• A8STRMAC.LIB: String Macros, the ones I adapted from Karl Weigers work in the July 1986 issue of A.N.A.L.O.G magazine.
• A8STRFNC.LIB String Functions, the ones I adapted from Karl Weigers work in the July 1986 issue of A.N.A.L.O.G magazine.

The last three (2) files (A8STRMAC.LIB, and A8STRFNC.LIB) were broken down in the previous post “6502, String to Integer (and reverse)” so I will not break them down again here.  The A8FUNCS.LIB was also been broken down in several previous posts, including corrections, so I will not break it down again either.

Breakdown

The only file left to breakdown is the definitions file (A8DEFS.LIB).  I’ve tried to keep similar items together.  Here it is:

01 ; ------------------------------
02 ; Lib.: A8DEFS.LIB
03 ; Desc: Definitions Library
09 ; ------------------------------
99 ; I/O
0100 CIOV = $E456 ;CIO Vector
0110 ICHID = $0340 ;IOCB 0 S:
0120 ICCOM = $0342 ;IOCB Command
0130 ICBAL = $0344 ;Xfer Buffer Adr
0140 ICBAH = $0345
0150 ICBLL = $0348 ;Buffer Len
0160 ICBLH = $0349
0162 ICAX1 = $0350 ;AUX byte 1
0164 ICAX2 = $0351 ;AUX byte 2
0499 ; Cursor
0500 LMARG = $52 ;82d
0510 ROWCRS = $54 ;84d
0520 COLCRS = $55 ;85d
0799 ; Character
0800 EOL = $9B ;155d
0810 EOS = $00
0820 CLS = $7D ;125d
0830 CIX = $F2 ;Index to INBUFF
0832 INBUFF = $F3 ;2 byte InBuf Ptr
0840 LBUFF = $0580 ;128 bytes
0899 ; Floating Point
0901 FPTEMP = $0482 ; User Mem 126 bytes
0902 ASCFP = $D800 ; ATASCII to FP
0904 FPASC = $D8E6 ; FP to ATASCII
0906 INTFP = $D9AA ; INT to FP
0908 FPINT = $D9D2 ; FP to INT
0910 FPSUB = $DA60 ; FR0-FR1
0912 FPADD = $DA66 ; FR0+FR1
0914 FPMUL = $DADB ; FR0*FR1
0916 FPDIV = $DB28 ; FR0/FR1
0918 FPLD0R = $DD89 ; Load using X,Y
0920 FPLD0P = $DD8D ; Load using FLPTR
0922 FPLD1R = $DD98 ; Load using X,Y
0924 FPLD1P = $DD9C ; Load using FLPTR
0926 FPSTOR = $DDA7 ; Store using X,Y
0928 FPSTOP = $DDA8 ; Store using FLPTR
0930 FPMOVE = $DDB6 ; FR0 to FR1
0940 FPZFR0 = $DA44 ; FR0 = 0
0942 FPZAF1 = $DA46 ; Reg in X = 0
0944 FPPTR1 = $FC ; 2 byte ptr User FP1
0946 FPPTR2 = $FE ; 2 byte ptr User FP2
1000 ; Misc
1010 RANDM = $D20A

• 99 to 164: CIO (Central IO addresses)
• 499 to 520: Cursor and margin addresses
• 799 to 840: Character values and pointer locations
• 899 to 946: Atari floating point routines.  At one point I was going to try to use these for the string/integer routines.
• 1000+: Misc addresses

Usage

When I write a program, I include A8DEFS.LIB and A8FUNCS.LIB first.  Then if I need string to integer or integer to string support I include A8STRMAC.LIB at the beginning and A8STRFNC.LIB at the end of the program source.  This pulls all the pieces in at the right time during assembly.

You can download an ATR file with them on it here.  It is named as PDF, but it is really an ATR due to a limitation with the hosting site.  Use your browsers “download as” function and change the name: A8LIBV10.ATR

Next

Next time I will demonstrate the library being used in my first fully functional, albeit simple, assembly language program.  Success!