acme/ACME_Lib/cbm/c64/float.a
2013-06-27 20:29:08 +00:00

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;ACME 0.94.4
!ifdef lib_cbm_c64_float_a !eof
lib_cbm_c64_float_a = 1
; Here are some definitions to help you call the floating-point functions of the
; C64's BASIC ROM. They work on "float registers", which are actually just
; structures in zero page:
fac1_base = $61 ; base address of floating-point accumulator 1
fac2_base = $69 ; base address of floating-point accumulator 2
; There is really no need to use these addresses directly when calling the ROM
; functions. You'd only need the addresses when using <cbm/flpt.a>.
!source <cbm/flpt.a> ; include macro to store floats in six-byte FLPT format
!source <cbm/mflpt.a> ; include macro to store floats in five-byte MFLPT format
; convenience macros:
; some float functions need a memory address in A (low) and Y (high)
!macro movAY .adr {
lda #<.adr
ldy #>.adr
}
; ...or in X (low) and Y (high)
!macro movXY .adr {
ldx #<.adr
ldy #>.adr
}
; other float functions expect or output a value in Y (low) and A (high)
!macro movYA .val {
ldy #<.val
lda #>.val
}
!macro ldYA .adr {
ldy .adr
lda .adr + 1
}
!macro stYA .adr {
sty .adr
sta .adr + 1
}
; ...or in X (low) and A (high)
!macro ldXA .adr {
ldx .adr
lda .adr + 1
}
; constants in five-byte "mflpt" format
mflpt_pi = $aea8 ; 3.1415926...
mflpt_minus32768 = $b1a5 ; -32768
mflpt_1 = $b9bc ; 1
mflpt_half_sqr2 = $b9d6 ; SQR(2) / 2
mflpt_sqr2 = $b9db ; SQR(2)
mflpt_minus_point5 = $b9e0 ; -.5
mflpt_log_2 = $b9e5 ; LOG(2)
mflpt_10 = $baf9 ; 10
mflpt_99999999 = $bdb3 ; 99 999 999
mflpt_999999999 = $bdb8 ; 999 999 999
mflpt_1000000000 = $bdbd ; 1 000 000 000
mflpt_point5 = $bf11 ; .5, also known as 1 / 2
mflpt_log_2_reciprocal = $bfbf ; 1 / LOG(2)
mflpt_half_pi = $e2e0 ; PI / 2
mflpt_double_pi = $e2e5 ; 2 * PI (also see $e309)
mflpt_point25 = $e2ea ; .25, also known as 1 / 4
mflpt_2_pi = $e309 ; 2 * PI (also see $e2e5)
; functions - a few points to note:
; fac1/2 might get clobbered even if not mentioned in the function's name,
; because stuff like fac1_times_memAY will load the value from memory
; into fac2 first.
; for subtraction and division, the left operand is in fac2, the right operand in fac1.
fac1_print = $aabc ; print string representation of contents of fac1
fac1_to_signedYA = $b1aa ; might throw ILLEGAL QUANTITY
fac1_to_signed16 = $b1bf ; might throw ILLEGAL QUANTITY
fac1_read_signedYA = $b391 ; convert 16 bit signed int to float
fac1_read_unsignedY = $b3a2 ; convert 8 bit unsigned int to float
fac1_read_string = $b7b5 ; $22/23 must point to string, A must be string length
fac1_to_unsignedYA = $b7f7 ; might throw ILLEGAL QUANTITY (result is also in $14/15)
fac1_add_point5 = $b849 ; for rounding, call this before fac1_int
fac1_memAY_minus_fac1 = $b850 ; subtract fac1 from mflpt value
fac1_fac2_minus_fac1 = $b853
fac1_add_memAY = $b867 ; add mflpt value
fac1_add_fac2 = $b86a
fac1_log = $b9ea ; LOG()
fac1_times_memAY = $ba28 ; multiply by mflpt value
fac2_read_memAY = $ba8c ; load mflpt value from memory into fac2
fac2_read_mem_via0x22ptr = $ba90 ; load mflpt value from memory into fac2
fac1_times_10 = $bae2
fac1_divide_by_10 = $bafe
fac1_divide_memAY_by_fac1 = $bb0f ; divide mflpt value by fac1 value
fac1_read_memAY = $bba2 ; load mflpt value from memory into fac1
fac1_read_mem_via0x22ptr = $bba6 ; load mflpt value from memory into fac1
fac1_to_memXY = $bbd4 ; store fac1 to memory as mflpt
fac1_read_fac2 = $bbfc ; copy fac2 to fac1
fac2_read_fac1 = $bc0c ; copy fac1 to fac2
fac1_sign_to_A = $bc2b ; $ff, $0, $1 for negative, zero, positive
fac1_sgn = $bc39 ; SGN()
fac1_abs = $bc58 ; ABS()
fac1_compare_to_memAY = $bc5b ; compare to mflpt value in memory
fac1_to_signed32 = $bc9b
fac1_int = $bccc ; INT()
fac1_print_unsignedXA = $bdcd
fac1_to_string = $bddd ; string is stored at $0100 (address returned in AY)
fac1_sqr = $bf71 ; SQR()
fac1_fac2_to_the_power_of_memAY = $bf78
fac1_negate = $bfb4
fac1_exp = $bfed ; EXP()
; end of basic rom jumps to start of kernel rom!
fac1_rnd = $e097 ; RND()
fac1_cos = $e264 ; COS()
fac1_sin = $e26b ; SIN()
fac1_tan = $e2b4 ; TAN()
fac1_atn = $e30e ; ATN()