�  Osbits Module B/osb23
>�  Floating Point Arithmetic - Multiplication and Division
�  Version 2.0 30.5.87
( 
2*KEY1MO.3|M|NL.|M
< 
F� code% &350
P@zp=&80          :� Temporary workspace of 4 bytes, preserved
Z 
d� pass%=0 � 2 � 2
nP%=code%
x 
�[OPT pass%
� 
�A\  Transfer the two numbers from the � block to input_1 and 2
� 
�JSR enter_parameters
� 
�/\  Transfer numbers from input_1 and 2 into
�#\  workspace for multiplication
� 
�JSR transfer_in
� 
�<JSR fp_mult                  \ Multiplication subroutine
� 

)\  Transfer result into 'result_mult'

 


LDX #5

" 

,.transfer_out_loop

6 

@LDA fpws_1-1, X

JSTA result_mult-1, X

TDEX

^BNE transfer_out_loop 

h 

r/\  Transfer numbers from input_1 and 2 into

|\  workspace for division

� 

�JSR transfer_in

� 

�6JSR fp_div                   \ Division subroutine

� 

�(\  Transfer result into 'result_div'

� 

�
LDX #5

� 

�.transfer_out_loop2

� 

�LDA fpws_1-1, X

�STA result_div-1, X
DEX
BNE transfer_out_loop2
 
&RTS
0 
:C\  Reservation of workspace.  Note bytes for sign of fp numbers
D4\  and for overflow (oflow) during calculations.
N7\  Also the fpws for each number is 7 bytes, not 5.
X<\  Note also that some workspace has a different name in
bA\  different parts of the program.  This aids conversion from
l\  the integer routines.
v 
� .input_1      OPT �EQUM(5,0)
� .input_2      OPT �EQUM(5,0)
�.fpws_1_sign  OPT �EQUB(0)
�.multiplicand
�
.dividend
� .fpws_1       OPT �EQUM(7,0)
�.fpws_2_sign  OPT �EQUB(0)
�.multiplier
�.divisor
� .fpws_2       OPT �EQUM(7,0)
�	.ppws
� .pdws         OPT �EQUM(6,0)
� .diff_ws      OPT �EQUM(6,0)
 .result_mult  OPT �EQUM(5,0)
 .result_div   OPT �EQUM(5,0)
 
 .enter_parameters
* 
4B\  This subroutine takes the two fp numbers from a � parameter
>9\  block at &600 and puts them in input_1 and input_2
H 
RGLDA zp                      \ Preserve zero page workspace on stack
\PHA
fLDA zp+1
pPHA
zLDA zp+2
�PHA
�LDA zp+3
�PHA
� 
�HLDA &601                    \ Move addresses from &600 block to zpws
�
STA zp
�LDA &602
�STA zp+1
�LDA &604
�STA zp+2
�LDA &605
�STA zp+3
� 

LDY #0
 
.enter_paras_loop
$ 
..LDA (zp), Y                 \ First number
8STA input_1, Y
B/LDA (zp+2), Y               \ Second number
LSTA input_2, Y
V 
`INY
j
CPY #5
tBNE enter_paras_loop
~ 
�9PLA                         \ Restore zpws from stack
�STA zp+3
�PLA
�STA zp+2
�PLA
�STA zp+1
�PLA
�
STA zp
�RTS
� 
�.transfer_in
� 
7\  This subroutine takes the numbers in input_1 and

1\  input_2 and puts them in fpws_1 and fpws_2
 

LDX #5
( 
2.transfer_in_loop
< 
FLDA input_1-1, X
PSTA fpws_1-1, X
ZLDA input_2-1, X
dSTA fpws_2-1, X
nDEX
xBNE transfer_in_loop 
� 
�RTS
� 
�.fp_mult
�  
�5\  Multiplies the numbers in fpws_1 by the number
�.\  in fpws_1 and puts the result in fpws_1
� 
�-\  First allow for zeros in the workspace
� 
�LDA fpws_1+1
�J�A fpws_1                  \ Zero if exponent & top mantissa byte zero
�CBEQ make_zero               \ If 1st no is zero then result = 0
  
LDA fpws_2+1
J�A fpws_2                  \ Zero if exponent & top mantissa byte zero
"CBEQ make_zero               \ If 2nd no is zero then result = 0
, 
6\  If result is not zero
@ 
J?JSR move_sign_bit           \ Move sign and restore top bit
T 
^JSR mult_denormalise
h 
rJSR mult_mantissae
| 
�JSR renormalise_muldiv
� 
�JSR replace_sign_bit
� 
�RTS
� 
�.fp_div
�  
�8\  Divides the number in fpws_1 by the one in fpws_2
�$\  and puts the result in fpws_1
� 
�-\  First allow for zeros in the workspace
�  
LDA fpws_2+1
J�A fpws_2                  \ Zero if exponent & top mantissa byte zero
ABEQ div_by_zero             \ If 2nd no is 0 we have an error
& 
0LDA fpws_1+1
:J�A fpws_1                  \ Zero if exponent & top mantissa byte zero
DCBEQ make_zero               \ If 1st no is zero then result = 0
N 
X?JSR move_sign_bit           \ Move sign and restore top bit
b 
lJSR div_denormalise
v 
�JSR div_mantissae
� 
�JSR renormalise_muldiv
� 
�JSR replace_sign_bit
� 
�RTS
� 
�.make_zero
� 
�%\  This routine makes fpws_1 zero
� 
�
LDA #0

LDX #5
 
.make_zero_loop
  
*STA fpws_1-1, X
4DEX
>BNE make_zero_loop
H 
RRTS
\ 
f.div_by_zero
p 
z,\  This is an error condition, number 18
� 
�BRK
�OPT �EQUB(18)
�*OPT �EQUS("Attempt to divide by zero")
�OPT �EQUB(0)
� 
�.move_sign_bit
� 
�H\  This routine transfers the sign bit from the top of the mantissae
�@\  and puts it into a sign byte - �ing to leave top bit only
�5\  and then restores the top bit of the mantissae
�  
�LDA fpws_1+1
	
� #&80
	FSTA fpws_1_sign             \ fpws_1_sign is -ve if number was -ve
	LDA #&80
	$�A fpws_1+1
	.DSTA fpws_1+1                \ Restores the top bit of the number
	8 
	BLDA fpws_2+1
	L
� #&80
	VFSTA fpws_2_sign             \ fpws_2_sign is -ve if number was -ve
	`LDA #&80
	j�A fpws_2+1
	tDSTA fpws_2+1                \ Restores the top bit of the number
	~ 
	�RTS
	� 
	�.mult_denormalise
	� 
	�:\  First, both numbers must be shifted down by 2 bytes
	�=\  and exponents both increased by 16.  This ensures that
	�*\  the final number does not overflow.
	� 
	�LDX #16
	� 
	�!.mult_denormalise_rotate_loop
	� 
7LSR fpws_1+1                \ Rotate mantissa right

ROR fpws_1+2
ROR fpws_1+3
ROR fpws_1+4
( 
2LSR fpws_2+1
<ROR fpws_2+2
FROR fpws_2+3
PROR fpws_2+4
Z 
dDEX
n$BNE mult_denormalise_rotate_loop
x 
�"\ Calculate exponent of result
� 
�SEC
�LDA fpws_1
�CSBC #&80                    \ Subtract &80 factor from exponent
�STA fpws_1
� 
�SEC
�LDA fpws_2
�BSBC #&80                    \ This is part of BBC BASIC format
�CLC
�ADC fpws_1
�HBVS mult_oflow              \ Overflow flag set if result sign wrong
CLC
BADC #&80                    \ Convert back to BBC BASIC format
STA fpws_1
" 
,RTS
6 
@.mult_oflow
J 
TBPL very_small
^?BRK                         \ An error condition, number 20
hOPT  �EQUB(20)
r7OPT  �EQUS("Number overflow during multiplication")
|OPT  �EQUB(0)
� 
�.very_small
� 
�EJMP make_zero               \ Answer is so small it is zero (ish)
� 
�.div_denormalise
� 
�9\  Shift the divisor right by 2 bytes to aid division
� 
�LDX #16
� 
�.div_den_loop
� 
LSR divisor+1
ROR divisor+2 
ROR divisor+3
&ROR divisor+4
0ROR divisor+5
:ROR divisor+6
D 
NDEX
XBNE div_den_loop
b 
l+\  Calculate initial exponent of result
v 
�SEC
�LDA fpws_2
�CSBC #&80                    \ Subtract &80 factor from exponent
�STA fpws_2
� 
�SEC
�LDA fpws_1
�BSBC #&80                    \ This is part of BBC BASIC format
�SEC
�SBC fpws_2
�HBVS div_oflow               \ Overflow flag set if result sign wrong
�CLC
�BADC #&80                    \ Convert back to BBC BASIC format

CLC

HADC #&20                    \ Add 32 to compensate for denormalising

STA fpws_1

  

*RTS

4 

>.div_oflow

H 

RBMI too_big_div

\JMP make_zero

f 

p.too_big_div

z 

�BRK

�COPT  �EQUB(20)             \ A BASIC error condition, number 20

�1OPT  �EQUS("Number overflow during division")

�OPT  �EQUB(0)

� 

�.mult_mantissae

� 

�9\  Assumes that numbers to be multiplied are put into

�5\  multiplicand and multiplier.  ppws is used for

�5\  partial product. Result is put into multiplier

� 

�
LDA #0

�;STA ppws              \ Clear partial product workspace
STA ppws+1
STA ppws+2
STA ppws+3
$ 
.DLDX #32               \ Carry out 32 times for 32 bit arithmetic
8 
B3LSR multiplier+1      \ Rotate multiplier right
LROR multiplier+2
VROR multiplier+3
`ROR multiplier+4
j 
t
.mbm_loop
~ 
�:BCC no_add_mbm        \ Is next bit of multiplier set?
�CLC
�,LDA multiplicand+4    \ Add multiplicand
�ADC ppws+3
�STA ppws+3
�LDA multiplicand+3
�ADC ppws+2
�STA ppws+2
�LDA multiplicand+2
�ADC ppws+1
�STA ppws+1
�LDA multiplicand+1
ADC ppws

STA ppws
 
.no_add_mbm
( 
2:LSR ppws              \ Rotate ppws & multiplier right
<ROR ppws+1
FROR ppws+2
PROR ppws+3
ZROR multiplier+1
dROR multiplier+2
nROR multiplier+3
xROR multiplier+4
�9DEX                   \ Counting down from 32 to zero
�BNE mbm_loop
� 
�*\  Put result in multiplicand (fpws_1)
� 
�
LDX #4
� 
�.swap_mm_loop
� 
�LDA multiplier, X
�STA multiplicand, X
�DEX
�BNE swap_mm_loop
 
RTS
 
".div_mantissae
, 
65\  Dividend is in dividend, divisor is in divisor
@$\  On exit result is in dividend
J"\  pdws holds partial dividend
T6\  diff_ws is temp ws to hold pdiv-div for testing
^ 
h@LDA #0                     \ Set partial dividend ws to zero
rSTA pdws
|STA pdws+1
�STA pdws+2
�STA pdws+3
�STA pdws+4
�STA pdws+5
� 
�0LDX #48                    \ 48 bit dividend
� 
�
.mbd_loop
� 
�KASL dividend+6             \ Rotate dividend left into partial dividend
�ROL dividend+5
�ROL dividend+4
�ROL dividend+3
ROL dividend+2
ROL dividend+1
ROL pdws+5
&ROL pdws+4
0ROL pdws+3
:ROL pdws+2
DROL pdws+1
NROL pdws
X 
bSEC
lGLDA pdws+5                 \ Subtract divisor from partial dividend
vSBC divisor+6
�STA diff_ws+5
�LDA pdws+4
�SBC divisor+5
�STA diff_ws+4
�LDA pdws+3
�SBC divisor+4
�STA diff_ws+3
�LDA pdws+2
�SBC divisor+3
�STA diff_ws+2
�LDA pdws+1
�SBC divisor+2
�STA diff_ws+1
LDA pdws
SBC divisor+1
STA diff_ws
  
*?BCC no_subtract_mbd        \ Carry set if diff_ws > divisor
4 
>CINC dividend+6             \ Increase result if we can subtract
H
LDY #6
R 
\.diff_w_to_pdws_loop
f 
pLDA diff_ws-1, Y
zSTA pdws-1, Y
� 
�DEY
�BNE diff_w_to_pdws_loop
� 
�.no_subtract_mbd
� 
�)DEX                        \ Next bit
�BNE mbd_loop
� 
�RTS
� 
�.renormalise_muldiv
� 
C\ This routine modifies the mantissa and exponent of the result
,\ To produce a normalised format number.
 
$?\  First trap a zero result, or loops will run indefinately
. 
8LDA fpws_1+1
B�A fpws_1+2
L�A fpws_1+3
V�A fpws_1+4
`�A fpws_1+5
j�A fpws_1+6
t 
~BEQ zero_norm
� 
�FLDA fpws_1+1                \ Top byte of mantissa is shifted left
�ABMI normalised              \ until top bit is set (i.e. -ve)
� 
�.shift_left_loop
� 
�7DEC fpws_1                  \ Decrease the exponent
�CASL fpws_1+6                \ Shift mantissa left to compensate
�ROL fpws_1+5
�ROL fpws_1+4
�ROL fpws_1+3
�ROL fpws_1+2
ROL fpws_1+1

 
BPL shift_left_loop
 
(.normalised
2 
<5RTS                         \ Number renormalised
F 
P.zero_norm
Z 
d
LDA #0
nASTA fpws_1                  \ Clear exponent of a zero number
x 
�RTS
� 
�.replace_sign_bit
� 
�LDA fpws_1_sign
�G� fpws_2_sign             \ � signs together to produce result sign
�D� #&80                    \ We're only interested in the top bit
�CLC
�AADC #&7F                    \ &FF if top bit set - &7F if not
�5� fpws_1+1                \ Top bit reflects sign
�6STA fpws_1+1                \ Replace in workspace
� 
�RTS
 
]
�
" 
,�
6 
@4� '"Floating Point Multiplication and Division"'
J"� "Enter the first number "fp1
T#� "Enter the second number "fp2
^�
h 
r� code%,fp1,fp2
| 
��"Results:"'
�,� "Product (code) is  ";�fp(result_mult)
�#� "Product (BASIC) is ";fp1*fp2
� 
�,� "Quotient (code) is  ";�fp(result_div)
�$� "Quotient (BASIC) is ";fp1/fp2
� 
�� �
� 
��
� 
�**** EQUate a Byte ****
�� �EQUB(N%)
?P%=N% � 256
� (pass% � 3) = 3 � � ~?P%
P%=P%+1
&
=pass%
0 
:**** EQUate a String ****
D� �EQUS(N$)
N� N%
X� 40
b� N%=1 � �(N$)
lK%=�(�N$,N%,1))
vP%?(N%-1)=K%
�%� (pass% � 3) = 3 � � ~P%?(N%-1);
��
�� (pass% � 3) = 3 � �
�P%=P%+�(N$)
�� 0
�
=pass%
� 
�(**** EQUate a section of Memory ****
�� �EQUM(number%,byte%)
�� N%
�� 40
�� N%=0 � number%-1
�P%?N%=byte%
!� (pass% � 3) = 3 � � ~P%?N%;
�
� (pass% � 3) = 3 � �
 P%=P%+number%
*� 0
4
=pass%
> 
H**** Reverse FP ****
RPuts fp number from memory
\into variable `
f� �fp(mem%)
p� M%, N%
z`=0
�M% = 3+(!&4C0 � &FFFF)
�� N%=0 � 4
�M%?N%=mem%?N%
��
�=`
�

00000000  0d 00 0a 1c f4 20 20 4f  73 62 69 74 73 20 4d 6f  |.....  Osbits Mo|
00000010  64 75 6c 65 20 42 2f 6f  73 62 32 33 0d 00 14 3e  |dule B/osb23...>|
00000020  f4 20 20 46 6c 6f 61 74  69 6e 67 20 50 6f 69 6e  |.  Floating Poin|
00000030  74 20 41 72 69 74 68 6d  65 74 69 63 20 2d 20 4d  |t Arithmetic - M|
00000040  75 6c 74 69 70 6c 69 63  61 74 69 6f 6e 20 61 6e  |ultiplication an|
00000050  64 20 44 69 76 69 73 69  6f 6e 0d 00 1e 1a f4 20  |d Division..... |
00000060  20 56 65 72 73 69 6f 6e  20 32 2e 30 20 33 30 2e  | Version 2.0 30.|
00000070  35 2e 38 37 0d 00 28 05  20 0d 00 32 15 2a 4b 45  |5.87..(. ..2.*KE|
00000080  59 31 4d 4f 2e 33 7c 4d  7c 4e 4c 2e 7c 4d 0d 00  |Y1MO.3|M|NL.|M..|
00000090  3c 05 20 0d 00 46 10 de  20 63 6f 64 65 25 20 26  |<. ..F.. code% &|
000000a0  33 35 30 0d 00 50 40 7a  70 3d 26 38 30 20 20 20  |350..P@zp=&80   |
000000b0  20 20 20 20 20 20 20 3a  f4 20 54 65 6d 70 6f 72  |       :. Tempor|
000000c0  61 72 79 20 77 6f 72 6b  73 70 61 63 65 20 6f 66  |ary workspace of|
000000d0  20 34 20 62 79 74 65 73  2c 20 70 72 65 73 65 72  | 4 bytes, preser|
000000e0  76 65 64 0d 00 5a 05 20  0d 00 64 15 e3 20 70 61  |ved..Z. ..d.. pa|
000000f0  73 73 25 3d 30 20 b8 20  32 20 88 20 32 0d 00 6e  |ss%=0 . 2 . 2..n|
00000100  0c 50 25 3d 63 6f 64 65  25 0d 00 78 05 20 0d 00  |.P%=code%..x. ..|
00000110  82 0e 5b 4f 50 54 20 70  61 73 73 25 0d 00 8c 05  |..[OPT pass%....|
00000120  20 0d 00 96 41 5c 20 20  54 72 61 6e 73 66 65 72  | ...A\  Transfer|
00000130  20 74 68 65 20 74 77 6f  20 6e 75 6d 62 65 72 73  | the two numbers|
00000140  20 66 72 6f 6d 20 74 68  65 20 d6 20 62 6c 6f 63  | from the . bloc|
00000150  6b 20 74 6f 20 69 6e 70  75 74 5f 31 20 61 6e 64  |k to input_1 and|
00000160  20 32 0d 00 a0 05 20 0d  00 aa 18 4a 53 52 20 65  | 2.... ....JSR e|
00000170  6e 74 65 72 5f 70 61 72  61 6d 65 74 65 72 73 0d  |nter_parameters.|
00000180  00 b4 05 20 0d 00 be 2f  5c 20 20 54 72 61 6e 73  |... .../\  Trans|
00000190  66 65 72 20 6e 75 6d 62  65 72 73 20 66 72 6f 6d  |fer numbers from|
000001a0  20 69 6e 70 75 74 5f 31  20 61 6e 64 20 32 20 69  | input_1 and 2 i|
000001b0  6e 74 6f 0d 00 c8 23 5c  20 20 77 6f 72 6b 73 70  |nto...#\  worksp|
000001c0  61 63 65 20 66 6f 72 20  6d 75 6c 74 69 70 6c 69  |ace for multipli|
000001d0  63 61 74 69 6f 6e 0d 00  d2 05 20 0d 00 dc 13 4a  |cation.... ....J|
000001e0  53 52 20 74 72 61 6e 73  66 65 72 5f 69 6e 0d 00  |SR transfer_in..|
000001f0  e6 05 20 0d 00 f0 3c 4a  53 52 20 66 70 5f 6d 75  |.. ...<JSR fp_mu|
00000200  6c 74 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |lt              |
00000210  20 20 20 20 5c 20 4d 75  6c 74 69 70 6c 69 63 61  |    \ Multiplica|
00000220  74 69 6f 6e 20 73 75 62  72 6f 75 74 69 6e 65 0d  |tion subroutine.|
00000230  00 fa 05 20 0d 01 04 29  5c 20 20 54 72 61 6e 73  |... ...)\  Trans|
00000240  66 65 72 20 72 65 73 75  6c 74 20 69 6e 74 6f 20  |fer result into |
00000250  27 72 65 73 75 6c 74 5f  6d 75 6c 74 27 0d 01 0e  |'result_mult'...|
00000260  05 20 0d 01 18 0a 4c 44  58 20 23 35 0d 01 22 05  |. ....LDX #5..".|
00000270  20 0d 01 2c 16 2e 74 72  61 6e 73 66 65 72 5f 6f  | ..,..transfer_o|
00000280  75 74 5f 6c 6f 6f 70 0d  01 36 05 20 0d 01 40 13  |ut_loop..6. ..@.|
00000290  4c 44 41 20 66 70 77 73  5f 31 2d 31 2c 20 58 0d  |LDA fpws_1-1, X.|
000002a0  01 4a 18 53 54 41 20 72  65 73 75 6c 74 5f 6d 75  |.J.STA result_mu|
000002b0  6c 74 2d 31 2c 20 58 0d  01 54 07 44 45 58 0d 01  |lt-1, X..T.DEX..|
000002c0  5e 1a 42 4e 45 20 74 72  61 6e 73 66 65 72 5f 6f  |^.BNE transfer_o|
000002d0  75 74 5f 6c 6f 6f 70 20  0d 01 68 05 20 0d 01 72  |ut_loop ..h. ..r|
000002e0  2f 5c 20 20 54 72 61 6e  73 66 65 72 20 6e 75 6d  |/\  Transfer num|
000002f0  62 65 72 73 20 66 72 6f  6d 20 69 6e 70 75 74 5f  |bers from input_|
00000300  31 20 61 6e 64 20 32 20  69 6e 74 6f 0d 01 7c 1d  |1 and 2 into..|.|
00000310  5c 20 20 77 6f 72 6b 73  70 61 63 65 20 66 6f 72  |\  workspace for|
00000320  20 64 69 76 69 73 69 6f  6e 0d 01 86 05 20 0d 01  | division.... ..|
00000330  90 13 4a 53 52 20 74 72  61 6e 73 66 65 72 5f 69  |..JSR transfer_i|
00000340  6e 0d 01 9a 05 20 0d 01  a4 36 4a 53 52 20 66 70  |n.... ...6JSR fp|
00000350  5f 64 69 76 20 20 20 20  20 20 20 20 20 20 20 20  |_div            |
00000360  20 20 20 20 20 20 20 5c  20 44 69 76 69 73 69 6f  |       \ Divisio|
00000370  6e 20 73 75 62 72 6f 75  74 69 6e 65 0d 01 ae 05  |n subroutine....|
00000380  20 0d 01 b8 28 5c 20 20  54 72 61 6e 73 66 65 72  | ...(\  Transfer|
00000390  20 72 65 73 75 6c 74 20  69 6e 74 6f 20 27 72 65  | result into 're|
000003a0  73 75 6c 74 5f 64 69 76  27 0d 01 c2 05 20 0d 01  |sult_div'.... ..|
000003b0  cc 0a 4c 44 58 20 23 35  0d 01 d6 05 20 0d 01 e0  |..LDX #5.... ...|
000003c0  17 2e 74 72 61 6e 73 66  65 72 5f 6f 75 74 5f 6c  |..transfer_out_l|
000003d0  6f 6f 70 32 0d 01 ea 05  20 0d 01 f4 13 4c 44 41  |oop2.... ....LDA|
000003e0  20 66 70 77 73 5f 31 2d  31 2c 20 58 0d 01 fe 17  | fpws_1-1, X....|
000003f0  53 54 41 20 72 65 73 75  6c 74 5f 64 69 76 2d 31  |STA result_div-1|
00000400  2c 20 58 0d 02 08 07 44  45 58 0d 02 12 1a 42 4e  |, X....DEX....BN|
00000410  45 20 74 72 61 6e 73 66  65 72 5f 6f 75 74 5f 6c  |E transfer_out_l|
00000420  6f 6f 70 32 0d 02 1c 05  20 0d 02 26 07 52 54 53  |oop2.... ..&.RTS|
00000430  0d 02 30 05 20 0d 02 3a  43 5c 20 20 52 65 73 65  |..0. ..:C\  Rese|
00000440  72 76 61 74 69 6f 6e 20  6f 66 20 77 6f 72 6b 73  |rvation of works|
00000450  70 61 63 65 2e 20 20 4e  6f 74 65 20 62 79 74 65  |pace.  Note byte|
00000460  73 20 66 6f 72 20 73 69  67 6e 20 6f 66 20 66 70  |s for sign of fp|
00000470  20 6e 75 6d 62 65 72 73  0d 02 44 34 5c 20 20 61  | numbers..D4\  a|
00000480  6e 64 20 66 6f 72 20 6f  76 65 72 66 6c 6f 77 20  |nd for overflow |
00000490  28 6f 66 6c 6f 77 29 20  64 75 72 69 6e 67 20 63  |(oflow) during c|
000004a0  61 6c 63 75 6c 61 74 69  6f 6e 73 2e 0d 02 4e 37  |alculations...N7|
000004b0  5c 20 20 41 6c 73 6f 20  74 68 65 20 66 70 77 73  |\  Also the fpws|
000004c0  20 66 6f 72 20 65 61 63  68 20 6e 75 6d 62 65 72  | for each number|
000004d0  20 69 73 20 37 20 62 79  74 65 73 2c 20 6e 6f 74  | is 7 bytes, not|
000004e0  20 35 2e 0d 02 58 3c 5c  20 20 4e 6f 74 65 20 61  | 5...X<\  Note a|
000004f0  6c 73 6f 20 74 68 61 74  20 73 6f 6d 65 20 77 6f  |lso that some wo|
00000500  72 6b 73 70 61 63 65 20  68 61 73 20 61 20 64 69  |rkspace has a di|
00000510  66 66 65 72 65 6e 74 20  6e 61 6d 65 20 69 6e 0d  |fferent name in.|
00000520  02 62 41 5c 20 20 64 69  66 66 65 72 65 6e 74 20  |.bA\  different |
00000530  70 61 72 74 73 20 6f 66  20 74 68 65 20 70 72 6f  |parts of the pro|
00000540  67 72 61 6d 2e 20 20 54  68 69 73 20 61 69 64 73  |gram.  This aids|
00000550  20 63 6f 6e 76 65 72 73  69 6f 6e 20 66 72 6f 6d  | conversion from|
00000560  0d 02 6c 1c 5c 20 20 74  68 65 20 69 6e 74 65 67  |..l.\  the integ|
00000570  65 72 20 72 6f 75 74 69  6e 65 73 2e 0d 02 76 05  |er routines...v.|
00000580  20 0d 02 80 20 2e 69 6e  70 75 74 5f 31 20 20 20  | ... .input_1   |
00000590  20 20 20 4f 50 54 20 a4  45 51 55 4d 28 35 2c 30  |   OPT .EQUM(5,0|
000005a0  29 0d 02 8a 20 2e 69 6e  70 75 74 5f 32 20 20 20  |)... .input_2   |
000005b0  20 20 20 4f 50 54 20 a4  45 51 55 4d 28 35 2c 30  |   OPT .EQUM(5,0|
000005c0  29 0d 02 94 1e 2e 66 70  77 73 5f 31 5f 73 69 67  |).....fpws_1_sig|
000005d0  6e 20 20 4f 50 54 20 a4  45 51 55 42 28 30 29 0d  |n  OPT .EQUB(0).|
000005e0  02 9e 11 2e 6d 75 6c 74  69 70 6c 69 63 61 6e 64  |....multiplicand|
000005f0  0d 02 a8 0d 2e 64 69 76  69 64 65 6e 64 0d 02 b2  |.....dividend...|
00000600  20 2e 66 70 77 73 5f 31  20 20 20 20 20 20 20 4f  | .fpws_1       O|
00000610  50 54 20 a4 45 51 55 4d  28 37 2c 30 29 0d 02 bc  |PT .EQUM(7,0)...|
00000620  1e 2e 66 70 77 73 5f 32  5f 73 69 67 6e 20 20 4f  |..fpws_2_sign  O|
00000630  50 54 20 a4 45 51 55 42  28 30 29 0d 02 c6 0f 2e  |PT .EQUB(0).....|
00000640  6d 75 6c 74 69 70 6c 69  65 72 0d 02 d0 0c 2e 64  |multiplier.....d|
00000650  69 76 69 73 6f 72 0d 02  da 20 2e 66 70 77 73 5f  |ivisor... .fpws_|
00000660  32 20 20 20 20 20 20 20  4f 50 54 20 a4 45 51 55  |2       OPT .EQU|
00000670  4d 28 37 2c 30 29 0d 02  e4 09 2e 70 70 77 73 0d  |M(7,0).....ppws.|
00000680  02 ee 20 2e 70 64 77 73  20 20 20 20 20 20 20 20  |.. .pdws        |
00000690  20 4f 50 54 20 a4 45 51  55 4d 28 36 2c 30 29 0d  | OPT .EQUM(6,0).|
000006a0  02 f8 20 2e 64 69 66 66  5f 77 73 20 20 20 20 20  |.. .diff_ws     |
000006b0  20 4f 50 54 20 a4 45 51  55 4d 28 36 2c 30 29 0d  | OPT .EQUM(6,0).|
000006c0  03 02 20 2e 72 65 73 75  6c 74 5f 6d 75 6c 74 20  |.. .result_mult |
000006d0  20 4f 50 54 20 a4 45 51  55 4d 28 35 2c 30 29 0d  | OPT .EQUM(5,0).|
000006e0  03 0c 20 2e 72 65 73 75  6c 74 5f 64 69 76 20 20  |.. .result_div  |
000006f0  20 4f 50 54 20 a4 45 51  55 4d 28 35 2c 30 29 0d  | OPT .EQUM(5,0).|
00000700  03 16 05 20 0d 03 20 15  2e 65 6e 74 65 72 5f 70  |... .. ..enter_p|
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00000760  0d 03 3e 39 5c 20 20 62  6c 6f 63 6b 20 61 74 20  |..>9\  block at |
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00000790  64 20 69 6e 70 75 74 5f  32 0d 03 48 05 20 0d 03  |d input_2..H. ..|
000007a0  52 47 4c 44 41 20 7a 70  20 20 20 20 20 20 20 20  |RGLDA zp        |
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000007e0  73 74 61 63 6b 0d 03 5c  07 50 48 41 0d 03 66 0c  |stack..\.PHA..f.|
000007f0  4c 44 41 20 7a 70 2b 31  0d 03 70 07 50 48 41 0d  |LDA zp+1..p.PHA.|
00000800  03 7a 0c 4c 44 41 20 7a  70 2b 32 0d 03 84 07 50  |.z.LDA zp+2....P|
00000810  48 41 0d 03 8e 0c 4c 44  41 20 7a 70 2b 33 0d 03  |HA....LDA zp+3..|
00000820  98 07 50 48 41 0d 03 a2  05 20 0d 03 ac 48 4c 44  |..PHA.... ...HLD|
00000830  41 20 26 36 30 31 20 20  20 20 20 20 20 20 20 20  |A &601          |
00000840  20 20 20 20 20 20 20 20  20 20 5c 20 4d 6f 76 65  |          \ Move|
00000850  20 61 64 64 72 65 73 73  65 73 20 66 72 6f 6d 20  | addresses from |
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00000870  77 73 0d 03 b6 0a 53 54  41 20 7a 70 0d 03 c0 0c  |ws....STA zp....|
00000880  4c 44 41 20 26 36 30 32  0d 03 ca 0c 53 54 41 20  |LDA &602....STA |
00000890  7a 70 2b 31 0d 03 d4 0c  4c 44 41 20 26 36 30 34  |zp+1....LDA &604|
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000008b0  4c 44 41 20 26 36 30 35  0d 03 f2 0c 53 54 41 20  |LDA &605....STA |
000008c0  7a 70 2b 33 0d 03 fc 05  20 0d 04 06 0a 4c 44 59  |zp+3.... ....LDY|
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000008e0  65 72 5f 70 61 72 61 73  5f 6c 6f 6f 70 0d 04 24  |er_paras_loop..$|
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00000900  59 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |Y               |
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00000930  20 59 0d 04 42 2f 4c 44  41 20 28 7a 70 2b 32 29  | Y..B/LDA (zp+2)|
00000940  2c 20 59 20 20 20 20 20  20 20 20 20 20 20 20 20  |, Y             |
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00000980  04 6a 0a 43 50 59 20 23  35 0d 04 74 18 42 4e 45  |.j.CPY #5..t.BNE|
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000009a0  70 0d 04 7e 05 20 0d 04  88 39 50 4c 41 20 20 20  |p..~. ...9PLA   |
000009b0  20 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |                |
000009c0  20 20 20 20 20 20 5c 20  52 65 73 74 6f 72 65 20  |      \ Restore |
000009d0  7a 70 77 73 20 66 72 6f  6d 20 73 74 61 63 6b 0d  |zpws from stack.|
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000009f0  4c 41 0d 04 a6 0c 53 54  41 20 7a 70 2b 32 0d 04  |LA....STA zp+2..|
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00000a10  31 0d 04 c4 07 50 4c 41  0d 04 ce 0a 53 54 41 20  |1....PLA....STA |
00000a20  7a 70 0d 04 d8 07 52 54  53 0d 04 e2 05 20 0d 04  |zp....RTS.... ..|
00000a30  ec 10 2e 74 72 61 6e 73  66 65 72 5f 69 6e 0d 04  |...transfer_in..|
00000a40  f6 05 20 0d 05 00 37 5c  20 20 54 68 69 73 20 73  |.. ...7\  This s|
00000a50  75 62 72 6f 75 74 69 6e  65 20 74 61 6b 65 73 20  |ubroutine takes |
00000a60  74 68 65 20 6e 75 6d 62  65 72 73 20 69 6e 20 69  |the numbers in i|
00000a70  6e 70 75 74 5f 31 20 61  6e 64 0d 05 0a 31 5c 20  |nput_1 and...1\ |
00000a80  20 69 6e 70 75 74 5f 32  20 61 6e 64 20 70 75 74  | input_2 and put|
00000a90  73 20 74 68 65 6d 20 69  6e 20 66 70 77 73 5f 31  |s them in fpws_1|
00000aa0  20 61 6e 64 20 66 70 77  73 5f 32 0d 05 14 05 20  | and fpws_2.... |
00000ab0  0d 05 1e 0a 4c 44 58 20  23 35 0d 05 28 05 20 0d  |....LDX #5..(. .|
00000ac0  05 32 15 2e 74 72 61 6e  73 66 65 72 5f 69 6e 5f  |.2..transfer_in_|
00000ad0  6c 6f 6f 70 0d 05 3c 05  20 0d 05 46 14 4c 44 41  |loop..<. ..F.LDA|
00000ae0  20 69 6e 70 75 74 5f 31  2d 31 2c 20 58 0d 05 50  | input_1-1, X..P|
00000af0  13 53 54 41 20 66 70 77  73 5f 31 2d 31 2c 20 58  |.STA fpws_1-1, X|
00000b00  0d 05 5a 14 4c 44 41 20  69 6e 70 75 74 5f 32 2d  |..Z.LDA input_2-|
00000b10  31 2c 20 58 0d 05 64 13  53 54 41 20 66 70 77 73  |1, X..d.STA fpws|
00000b20  5f 32 2d 31 2c 20 58 0d  05 6e 07 44 45 58 0d 05  |_2-1, X..n.DEX..|
00000b30  78 19 42 4e 45 20 74 72  61 6e 73 66 65 72 5f 69  |x.BNE transfer_i|
00000b40  6e 5f 6c 6f 6f 70 20 0d  05 82 05 20 0d 05 8c 07  |n_loop .... ....|
00000b50  52 54 53 0d 05 96 05 20  0d 05 a0 0c 2e 66 70 5f  |RTS.... .....fp_|
00000b60  6d 75 6c 74 0d 05 aa 06  20 20 0d 05 b4 35 5c 20  |mult....  ...5\ |
00000b70  20 4d 75 6c 74 69 70 6c  69 65 73 20 74 68 65 20  | Multiplies the |
00000b80  6e 75 6d 62 65 72 73 20  69 6e 20 66 70 77 73 5f  |numbers in fpws_|
00000b90  31 20 62 79 20 74 68 65  20 6e 75 6d 62 65 72 0d  |1 by the number.|
00000ba0  05 be 2e 5c 20 20 69 6e  20 66 70 77 73 5f 31 20  |...\  in fpws_1 |
00000bb0  61 6e 64 20 70 75 74 73  20 74 68 65 20 72 65 73  |and puts the res|
00000bc0  75 6c 74 20 69 6e 20 66  70 77 73 5f 31 0d 05 c8  |ult in fpws_1...|
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00000c00  05 dc 05 20 0d 05 e6 10  4c 44 41 20 66 70 77 73  |... ....LDA fpws|
00000c10  5f 31 2b 31 0d 05 f0 4a  84 41 20 66 70 77 73 5f  |_1+1...J.A fpws_|
00000c20  31 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |1               |
00000c30  20 20 20 5c 20 5a 65 72  6f 20 69 66 20 65 78 70  |   \ Zero if exp|
00000c40  6f 6e 65 6e 74 20 26 20  74 6f 70 20 6d 61 6e 74  |onent & top mant|
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00000c60  fa 43 42 45 51 20 6d 61  6b 65 5f 7a 65 72 6f 20  |.CBEQ make_zero |
00000c70  20 20 20 20 20 20 20 20  20 20 20 20 20 20 5c 20  |              \ |
00000c80  49 66 20 31 73 74 20 6e  6f 20 69 73 20 7a 65 72  |If 1st no is zer|
00000c90  6f 20 74 68 65 6e 20 72  65 73 75 6c 74 20 3d 20  |o then result = |
00000ca0  30 0d 06 04 06 20 20 0d  06 0e 10 4c 44 41 20 66  |0....  ....LDA f|
00000cb0  70 77 73 5f 32 2b 31 0d  06 18 4a 84 41 20 66 70  |pws_2+1...J.A fp|
00000cc0  77 73 5f 32 20 20 20 20  20 20 20 20 20 20 20 20  |ws_2            |
00000cd0  20 20 20 20 20 20 5c 20  5a 65 72 6f 20 69 66 20  |      \ Zero if |
00000ce0  65 78 70 6f 6e 65 6e 74  20 26 20 74 6f 70 20 6d  |exponent & top m|
00000cf0  61 6e 74 69 73 73 61 20  62 79 74 65 20 7a 65 72  |antissa byte zer|
00000d00  6f 0d 06 22 43 42 45 51  20 6d 61 6b 65 5f 7a 65  |o.."CBEQ make_ze|
00000d10  72 6f 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |ro              |
00000d20  20 5c 20 49 66 20 32 6e  64 20 6e 6f 20 69 73 20  | \ If 2nd no is |
00000d30  7a 65 72 6f 20 74 68 65  6e 20 72 65 73 75 6c 74  |zero then result|
00000d40  20 3d 20 30 0d 06 2c 05  20 0d 06 36 1c 5c 20 20  | = 0..,. ..6.\  |
00000d50  49 66 20 72 65 73 75 6c  74 20 69 73 20 6e 6f 74  |If result is not|
00000d60  20 7a 65 72 6f 0d 06 40  05 20 0d 06 4a 3f 4a 53  | zero..@. ..J?JS|
00000d70  52 20 6d 6f 76 65 5f 73  69 67 6e 5f 62 69 74 20  |R move_sign_bit |
00000d80  20 20 20 20 20 20 20 20  20 20 5c 20 4d 6f 76 65  |          \ Move|
00000d90  20 73 69 67 6e 20 61 6e  64 20 72 65 73 74 6f 72  | sign and restor|
00000da0  65 20 74 6f 70 20 62 69  74 0d 06 54 05 20 0d 06  |e top bit..T. ..|
00000db0  5e 18 4a 53 52 20 6d 75  6c 74 5f 64 65 6e 6f 72  |^.JSR mult_denor|
00000dc0  6d 61 6c 69 73 65 0d 06  68 05 20 0d 06 72 16 4a  |malise..h. ..r.J|
00000dd0  53 52 20 6d 75 6c 74 5f  6d 61 6e 74 69 73 73 61  |SR mult_mantissa|
00000de0  65 0d 06 7c 05 20 0d 06  86 1a 4a 53 52 20 72 65  |e..|. ....JSR re|
00000df0  6e 6f 72 6d 61 6c 69 73  65 5f 6d 75 6c 64 69 76  |normalise_muldiv|
00000e00  0d 06 90 05 20 0d 06 9a  18 4a 53 52 20 72 65 70  |.... ....JSR rep|
00000e10  6c 61 63 65 5f 73 69 67  6e 5f 62 69 74 0d 06 a4  |lace_sign_bit...|
00000e20  05 20 0d 06 ae 07 52 54  53 0d 06 b8 05 20 0d 06  |. ....RTS.... ..|
00000e30  c2 0b 2e 66 70 5f 64 69  76 0d 06 cc 06 20 20 0d  |...fp_div....  .|
00000e40  06 d6 38 5c 20 20 44 69  76 69 64 65 73 20 74 68  |..8\  Divides th|
00000e50  65 20 6e 75 6d 62 65 72  20 69 6e 20 66 70 77 73  |e number in fpws|
00000e60  5f 31 20 62 79 20 74 68  65 20 6f 6e 65 20 69 6e  |_1 by the one in|
00000e70  20 66 70 77 73 5f 32 0d  06 e0 24 5c 20 20 61 6e  | fpws_2...$\  an|
00000e80  64 20 70 75 74 73 20 74  68 65 20 72 65 73 75 6c  |d puts the resul|
00000e90  74 20 69 6e 20 66 70 77  73 5f 31 0d 06 ea 05 20  |t in fpws_1.... |
00000ea0  0d 06 f4 2d 5c 20 20 46  69 72 73 74 20 61 6c 6c  |...-\  First all|
00000eb0  6f 77 20 66 6f 72 20 7a  65 72 6f 73 20 69 6e 20  |ow for zeros in |
00000ec0  74 68 65 20 77 6f 72 6b  73 70 61 63 65 0d 06 fe  |the workspace...|
00000ed0  06 20 20 0d 07 08 10 4c  44 41 20 66 70 77 73 5f  |.  ....LDA fpws_|
00000ee0  32 2b 31 0d 07 12 4a 84  41 20 66 70 77 73 5f 32  |2+1...J.A fpws_2|
00000ef0  20 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |                |
00000f00  20 20 5c 20 5a 65 72 6f  20 69 66 20 65 78 70 6f  |  \ Zero if expo|
00000f10  6e 65 6e 74 20 26 20 74  6f 70 20 6d 61 6e 74 69  |nent & top manti|
00000f20  73 73 61 20 62 79 74 65  20 7a 65 72 6f 0d 07 1c  |ssa byte zero...|
00000f30  41 42 45 51 20 64 69 76  5f 62 79 5f 7a 65 72 6f  |ABEQ div_by_zero|
00000f40  20 20 20 20 20 20 20 20  20 20 20 20 20 5c 20 49  |             \ I|
00000f50  66 20 32 6e 64 20 6e 6f  20 69 73 20 30 20 77 65  |f 2nd no is 0 we|
00000f60  20 68 61 76 65 20 61 6e  20 65 72 72 6f 72 0d 07  | have an error..|
00000f70  26 05 20 0d 07 30 10 4c  44 41 20 66 70 77 73 5f  |&. ..0.LDA fpws_|
00000f80  31 2b 31 0d 07 3a 4a 84  41 20 66 70 77 73 5f 31  |1+1..:J.A fpws_1|
00000f90  20 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |                |
00000fa0  20 20 5c 20 5a 65 72 6f  20 69 66 20 65 78 70 6f  |  \ Zero if expo|
00000fb0  6e 65 6e 74 20 26 20 74  6f 70 20 6d 61 6e 74 69  |nent & top manti|
00000fc0  73 73 61 20 62 79 74 65  20 7a 65 72 6f 0d 07 44  |ssa byte zero..D|
00000fd0  43 42 45 51 20 6d 61 6b  65 5f 7a 65 72 6f 20 20  |CBEQ make_zero  |
00000fe0  20 20 20 20 20 20 20 20  20 20 20 20 20 5c 20 49  |             \ I|
00000ff0  66 20 31 73 74 20 6e 6f  20 69 73 20 7a 65 72 6f  |f 1st no is zero|
00001000  20 74 68 65 6e 20 72 65  73 75 6c 74 20 3d 20 30  | then result = 0|
00001010  0d 07 4e 05 20 0d 07 58  3f 4a 53 52 20 6d 6f 76  |..N. ..X?JSR mov|
00001020  65 5f 73 69 67 6e 5f 62  69 74 20 20 20 20 20 20  |e_sign_bit      |
00001030  20 20 20 20 20 5c 20 4d  6f 76 65 20 73 69 67 6e  |     \ Move sign|
00001040  20 61 6e 64 20 72 65 73  74 6f 72 65 20 74 6f 70  | and restore top|
00001050  20 62 69 74 0d 07 62 05  20 0d 07 6c 17 4a 53 52  | bit..b. ..l.JSR|
00001060  20 64 69 76 5f 64 65 6e  6f 72 6d 61 6c 69 73 65  | div_denormalise|
00001070  0d 07 76 05 20 0d 07 80  15 4a 53 52 20 64 69 76  |..v. ....JSR div|
00001080  5f 6d 61 6e 74 69 73 73  61 65 0d 07 8a 05 20 0d  |_mantissae.... .|
00001090  07 94 1a 4a 53 52 20 72  65 6e 6f 72 6d 61 6c 69  |...JSR renormali|
000010a0  73 65 5f 6d 75 6c 64 69  76 0d 07 9e 05 20 0d 07  |se_muldiv.... ..|
000010b0  a8 18 4a 53 52 20 72 65  70 6c 61 63 65 5f 73 69  |..JSR replace_si|
000010c0  67 6e 5f 62 69 74 0d 07  b2 05 20 0d 07 bc 07 52  |gn_bit.... ....R|
000010d0  54 53 0d 07 c6 05 20 0d  07 d0 0e 2e 6d 61 6b 65  |TS.... .....make|
000010e0  5f 7a 65 72 6f 0d 07 da  05 20 0d 07 e4 25 5c 20  |_zero.... ...%\ |
000010f0  20 54 68 69 73 20 72 6f  75 74 69 6e 65 20 6d 61  | This routine ma|
00001100  6b 65 73 20 66 70 77 73  5f 31 20 7a 65 72 6f 0d  |kes fpws_1 zero.|
00001110  07 ee 05 20 0d 07 f8 0a  4c 44 41 20 23 30 0d 08  |... ....LDA #0..|
00001120  02 0a 4c 44 58 20 23 35  0d 08 0c 05 20 0d 08 16  |..LDX #5.... ...|
00001130  13 2e 6d 61 6b 65 5f 7a  65 72 6f 5f 6c 6f 6f 70  |..make_zero_loop|
00001140  0d 08 20 05 20 0d 08 2a  13 53 54 41 20 66 70 77  |.. . ..*.STA fpw|
00001150  73 5f 31 2d 31 2c 20 58  0d 08 34 07 44 45 58 0d  |s_1-1, X..4.DEX.|
00001160  08 3e 16 42 4e 45 20 6d  61 6b 65 5f 7a 65 72 6f  |.>.BNE make_zero|
00001170  5f 6c 6f 6f 70 0d 08 48  05 20 0d 08 52 07 52 54  |_loop..H. ..R.RT|
00001180  53 0d 08 5c 05 20 0d 08  66 10 2e 64 69 76 5f 62  |S..\. ..f..div_b|
00001190  79 5f 7a 65 72 6f 0d 08  70 05 20 0d 08 7a 2c 5c  |y_zero..p. ..z,\|
000011a0  20 20 54 68 69 73 20 69  73 20 61 6e 20 65 72 72  |  This is an err|
000011b0  6f 72 20 63 6f 6e 64 69  74 69 6f 6e 2c 20 6e 75  |or condition, nu|
000011c0  6d 62 65 72 20 31 38 0d  08 84 05 20 0d 08 8e 07  |mber 18.... ....|
000011d0  42 52 4b 0d 08 98 11 4f  50 54 20 a4 45 51 55 42  |BRK....OPT .EQUB|
000011e0  28 31 38 29 0d 08 a2 2a  4f 50 54 20 a4 45 51 55  |(18)...*OPT .EQU|
000011f0  53 28 22 41 74 74 65 6d  70 74 20 74 6f 20 64 69  |S("Attempt to di|
00001200  76 69 64 65 20 62 79 20  7a 65 72 6f 22 29 0d 08  |vide by zero")..|
00001210  ac 10 4f 50 54 20 a4 45  51 55 42 28 30 29 0d 08  |..OPT .EQUB(0)..|
00001220  b6 05 20 0d 08 c0 12 2e  6d 6f 76 65 5f 73 69 67  |.. .....move_sig|
00001230  6e 5f 62 69 74 0d 08 ca  05 20 0d 08 d4 48 5c 20  |n_bit.... ...H\ |
00001240  20 54 68 69 73 20 72 6f  75 74 69 6e 65 20 74 72  | This routine tr|
00001250  61 6e 73 66 65 72 73 20  74 68 65 20 73 69 67 6e  |ansfers the sign|
00001260  20 62 69 74 20 66 72 6f  6d 20 74 68 65 20 74 6f  | bit from the to|
00001270  70 20 6f 66 20 74 68 65  20 6d 61 6e 74 69 73 73  |p of the mantiss|
00001280  61 65 0d 08 de 40 5c 20  20 61 6e 64 20 70 75 74  |ae...@\  and put|
00001290  73 20 69 74 20 69 6e 74  6f 20 61 20 73 69 67 6e  |s it into a sign|
000012a0  20 62 79 74 65 20 2d 20  80 69 6e 67 20 74 6f 20  | byte - .ing to |
000012b0  6c 65 61 76 65 20 74 6f  70 20 62 69 74 20 6f 6e  |leave top bit on|
000012c0  6c 79 0d 08 e8 35 5c 20  20 61 6e 64 20 74 68 65  |ly...5\  and the|
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00002260  20 4f 6e 20 65 78 69 74  20 72 65 73 75 6c 74 20  | On exit result |
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00002380  20 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |                |
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00002480  4c 20 70 64 77 73 2b 33  0d 11 3a 0e 52 4f 4c 20  |L pdws+3..:.ROL |
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00002610  73 0d 12 20 05 20 0d 12  2a 3f 42 43 43 20 6e 6f  |s.. . ..*?BCC no|
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000026b0  2e 64 69 66 66 5f 77 5f  74 6f 5f 70 64 77 73 5f  |.diff_w_to_pdws_|
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00002730  b6 05 20 0d 12 c0 29 44  45 58 20 20 20 20 20 20  |.. ...)DEX      |
00002740  20 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |                |
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00002770  20 0d 12 de 07 52 54 53  0d 12 e8 05 20 0d 12 f2  | ....RTS.... ...|
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000027d0  66 20 74 68 65 20 72 65  73 75 6c 74 0d 13 10 2c  |f the result...,|
000027e0  5c 20 54 6f 20 70 72 6f  64 75 63 65 20 61 20 6e  |\ To produce a n|
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00002800  20 6e 75 6d 62 65 72 2e  0d 13 1a 05 20 0d 13 24  | number..... ..$|
00002810  3f 5c 20 20 46 69 72 73  74 20 74 72 61 70 20 61  |?\  First trap a|
00002820  20 7a 65 72 6f 20 72 65  73 75 6c 74 2c 20 6f 72  | zero result, or|
00002830  20 6c 6f 6f 70 73 20 77  69 6c 6c 20 72 75 6e 20  | loops will run |
00002840  69 6e 64 65 66 69 6e 61  74 65 6c 79 0d 13 2e 05  |indefinately....|
00002850  20 0d 13 38 10 4c 44 41  20 66 70 77 73 5f 31 2b  | ..8.LDA fpws_1+|
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00002870  0d 13 4c 0f 84 41 20 66  70 77 73 5f 31 2b 33 0d  |..L..A fpws_1+3.|
00002880  13 56 0f 84 41 20 66 70  77 73 5f 31 2b 34 0d 13  |.V..A fpws_1+4..|
00002890  60 0f 84 41 20 66 70 77  73 5f 31 2b 35 0d 13 6a  |`..A fpws_1+5..j|
000028a0  0f 84 41 20 66 70 77 73  5f 31 2b 36 0d 13 74 05  |..A fpws_1+6..t.|
000028b0  20 0d 13 7e 11 42 45 51  20 7a 65 72 6f 5f 6e 6f  | ..~.BEQ zero_no|
000028c0  72 6d 0d 13 88 05 20 0d  13 92 46 4c 44 41 20 66  |rm.... ...FLDA f|
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00002a00  77 73 5f 31 2b 34 0d 13  ec 10 52 4f 4c 20 66 70  |ws_1+4....ROL fp|
00002a10  77 73 5f 31 2b 33 0d 13  f6 10 52 4f 4c 20 66 70  |ws_1+3....ROL fp|
00002a20  77 73 5f 31 2b 32 0d 14  00 10 52 4f 4c 20 66 70  |ws_1+2....ROL fp|
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00002a40  50 4c 20 73 68 69 66 74  5f 6c 65 66 74 5f 6c 6f  |PL shift_left_lo|
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00002a70  54 53 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |TS              |
00002a80  20 20 20 20 20 20 20 20  20 20 20 5c 20 4e 75 6d  |           \ Num|
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00002aa0  0d 14 46 05 20 0d 14 50  0e 2e 7a 65 72 6f 5f 6e  |..F. ..P..zero_n|
00002ab0  6f 72 6d 0d 14 5a 05 20  0d 14 64 0a 4c 44 41 20  |orm..Z. ..d.LDA |
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00002ad0  20 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |                |
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00002af0  6e 74 20 6f 66 20 61 20  7a 65 72 6f 20 6e 75 6d  |nt of a zero num|
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00002b10  14 8c 05 20 0d 14 96 15  2e 72 65 70 6c 61 63 65  |... .....replace|
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00002b40  6e 0d 14 b4 47 82 20 66  70 77 73 5f 32 5f 73 69  |n...G. fpws_2_si|
00002b50  67 6e 20 20 20 20 20 20  20 20 20 20 20 20 20 5c  |gn             \|
00002b60  20 82 20 73 69 67 6e 73  20 74 6f 67 65 74 68 65  | . signs togethe|
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00002b80  75 6c 74 20 73 69 67 6e  0d 14 be 44 80 20 23 26  |ult sign...D. #&|
00002b90  38 30 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |80              |
00002ba0  20 20 20 20 20 20 5c 20  57 65 27 72 65 20 6f 6e  |      \ We're on|
00002bb0  6c 79 20 69 6e 74 65 72  65 73 74 65 64 20 69 6e  |ly interested in|
00002bc0  20 74 68 65 20 74 6f 70  20 62 69 74 0d 14 c8 07  | the top bit....|
00002bd0  43 4c 43 0d 14 d2 41 41  44 43 20 23 26 37 46 20  |CLC...AADC #&7F |
00002be0  20 20 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |                |
00002bf0  20 20 20 5c 20 26 46 46  20 69 66 20 74 6f 70 20  |   \ &FF if top |
00002c00  62 69 74 20 73 65 74 20  2d 20 26 37 46 20 69 66  |bit set - &7F if|
00002c10  20 6e 6f 74 0d 14 dc 35  80 20 66 70 77 73 5f 31  | not...5. fpws_1|
00002c20  2b 31 20 20 20 20 20 20  20 20 20 20 20 20 20 20  |+1              |
00002c30  20 20 5c 20 54 6f 70 20  62 69 74 20 72 65 66 6c  |  \ Top bit refl|
00002c40  65 63 74 73 20 73 69 67  6e 0d 14 e6 36 53 54 41  |ects sign...6STA|
00002c50  20 66 70 77 73 5f 31 2b  31 20 20 20 20 20 20 20  | fpws_1+1       |
00002c60  20 20 20 20 20 20 20 20  20 5c 20 52 65 70 6c 61  |         \ Repla|
00002c70  63 65 20 69 6e 20 77 6f  72 6b 73 70 61 63 65 0d  |ce in workspace.|
00002c80  14 f0 05 20 0d 14 fa 07  52 54 53 0d 15 04 05 20  |... ....RTS.... |
00002c90  0d 15 0e 05 5d 0d 15 18  05 ed 0d 15 22 05 20 0d  |....].......". .|
00002ca0  15 2c 05 f5 0d 15 36 05  20 0d 15 40 34 f1 20 27  |.,....6. ..@4. '|
00002cb0  22 46 6c 6f 61 74 69 6e  67 20 50 6f 69 6e 74 20  |"Floating Point |
00002cc0  4d 75 6c 74 69 70 6c 69  63 61 74 69 6f 6e 20 61  |Multiplication a|
00002cd0  6e 64 20 44 69 76 69 73  69 6f 6e 22 27 0d 15 4a  |nd Division"'..J|
00002ce0  22 e8 20 22 45 6e 74 65  72 20 74 68 65 20 66 69  |". "Enter the fi|
00002cf0  72 73 74 20 6e 75 6d 62  65 72 20 22 66 70 31 0d  |rst number "fp1.|
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00002d10  73 65 63 6f 6e 64 20 6e  75 6d 62 65 72 20 22 66  |second number "f|
00002d20  70 32 0d 15 5e 05 f1 0d  15 68 05 20 0d 15 72 13  |p2..^....h. ..r.|
00002d30  d6 20 63 6f 64 65 25 2c  66 70 31 2c 66 70 32 0d  |. code%,fp1,fp2.|
00002d40  15 7c 05 20 0d 15 86 10  f1 22 52 65 73 75 6c 74  |.|. ....."Result|
00002d50  73 3a 22 27 0d 15 90 2c  f1 20 22 50 72 6f 64 75  |s:"'...,. "Produ|
00002d60  63 74 20 28 63 6f 64 65  29 20 69 73 20 20 22 3b  |ct (code) is  ";|
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00002d80  0d 15 9a 23 f1 20 22 50  72 6f 64 75 63 74 20 28  |...#. "Product (|
00002d90  42 41 53 49 43 29 20 69  73 20 22 3b 66 70 31 2a  |BASIC) is ";fp1*|
00002da0  66 70 32 0d 15 a4 05 20  0d 15 ae 2c f1 20 22 51  |fp2.... ...,. "Q|
00002db0  75 6f 74 69 65 6e 74 20  28 63 6f 64 65 29 20 69  |uotient (code) i|
00002dc0  73 20 20 22 3b a4 66 70  28 72 65 73 75 6c 74 5f  |s  ";.fp(result_|
00002dd0  64 69 76 29 0d 15 b8 24  f1 20 22 51 75 6f 74 69  |div)...$. "Quoti|
00002de0  65 6e 74 20 28 42 41 53  49 43 29 20 69 73 20 22  |ent (BASIC) is "|
00002df0  3b 66 70 31 2f 66 70 32  0d 15 c2 05 20 0d 15 cc  |;fp1/fp2.... ...|
00002e00  07 fd 20 a3 0d 15 d6 05  20 0d 15 e0 05 e0 0d 15  |.. ..... .......|
00002e10  ea 05 20 0d 15 f4 1b 2a  2a 2a 2a 20 45 51 55 61  |.. ....**** EQUa|
00002e20  74 65 20 61 20 42 79 74  65 20 2a 2a 2a 2a 0d 15  |te a Byte ****..|
00002e30  fe 0f dd 20 a4 45 51 55  42 28 4e 25 29 0d 16 08  |... .EQUB(N%)...|
00002e40  10 3f 50 25 3d 4e 25 20  83 20 32 35 36 0d 16 12  |.?P%=N% . 256...|
00002e50  1e e7 20 28 70 61 73 73  25 20 80 20 33 29 20 3d  |.. (pass% . 3) =|
00002e60  20 33 20 8c 20 f1 20 7e  3f 50 25 0d 16 1c 0b 50  | 3 . . ~?P%....P|
00002e70  25 3d 50 25 2b 31 0d 16  26 0a 3d 70 61 73 73 25  |%=P%+1..&.=pass%|
00002e80  0d 16 30 05 20 0d 16 3a  1d 2a 2a 2a 2a 20 45 51  |..0. ..:.**** EQ|
00002e90  55 61 74 65 20 61 20 53  74 72 69 6e 67 20 2a 2a  |Uate a String **|
00002ea0  2a 2a 0d 16 44 0f dd 20  a4 45 51 55 53 28 4e 24  |**..D.. .EQUS(N$|
00002eb0  29 0d 16 4e 08 ea 20 4e  25 0d 16 58 08 fe 20 34  |)..N.. N%..X.. 4|
00002ec0  30 0d 16 62 12 e3 20 4e  25 3d 31 20 b8 20 a9 28  |0..b.. N%=1 . .(|
00002ed0  4e 24 29 0d 16 6c 13 4b  25 3d 97 28 c1 4e 24 2c  |N$)..l.K%=.(.N$,|
00002ee0  4e 25 2c 31 29 29 0d 16  76 10 50 25 3f 28 4e 25  |N%,1))..v.P%?(N%|
00002ef0  2d 31 29 3d 4b 25 0d 16  80 25 e7 20 28 70 61 73  |-1)=K%...%. (pas|
00002f00  73 25 20 80 20 33 29 20  3d 20 33 20 8c 20 f1 20  |s% . 3) = 3 . . |
00002f10  7e 50 25 3f 28 4e 25 2d  31 29 3b 0d 16 8a 05 ed  |~P%?(N%-1);.....|
00002f20  0d 16 94 19 e7 20 28 70  61 73 73 25 20 80 20 33  |..... (pass% . 3|
00002f30  29 20 3d 20 33 20 8c 20  f1 0d 16 9e 0f 50 25 3d  |) = 3 . .....P%=|
00002f40  50 25 2b a9 28 4e 24 29  0d 16 a8 07 fe 20 30 0d  |P%+.(N$)..... 0.|
00002f50  16 b2 0a 3d 70 61 73 73  25 0d 16 bc 05 20 0d 16  |...=pass%.... ..|
00002f60  c6 28 2a 2a 2a 2a 20 45  51 55 61 74 65 20 61 20  |.(**** EQUate a |
00002f70  73 65 63 74 69 6f 6e 20  6f 66 20 4d 65 6d 6f 72  |section of Memor|
00002f80  79 20 2a 2a 2a 2a 0d 16  d0 1a dd 20 a4 45 51 55  |y ****..... .EQU|
00002f90  4d 28 6e 75 6d 62 65 72  25 2c 62 79 74 65 25 29  |M(number%,byte%)|
00002fa0  0d 16 da 08 ea 20 4e 25  0d 16 e4 08 fe 20 34 30  |..... N%..... 40|
00002fb0  0d 16 ee 16 e3 20 4e 25  3d 30 20 b8 20 6e 75 6d  |..... N%=0 . num|
00002fc0  62 65 72 25 2d 31 0d 16  f8 0f 50 25 3f 4e 25 3d  |ber%-1....P%?N%=|
00002fd0  62 79 74 65 25 0d 17 02  21 e7 20 28 70 61 73 73  |byte%...!. (pass|
00002fe0  25 20 80 20 33 29 20 3d  20 33 20 8c 20 f1 20 7e  |% . 3) = 3 . . ~|
00002ff0  50 25 3f 4e 25 3b 0d 17  0c 05 ed 0d 17 16 19 e7  |P%?N%;..........|
00003000  20 28 70 61 73 73 25 20  80 20 33 29 20 3d 20 33  | (pass% . 3) = 3|
00003010  20 8c 20 f1 0d 17 20 11  50 25 3d 50 25 2b 6e 75  | . ... .P%=P%+nu|
00003020  6d 62 65 72 25 0d 17 2a  07 fe 20 30 0d 17 34 0a  |mber%..*.. 0..4.|
00003030  3d 70 61 73 73 25 0d 17  3e 05 20 0d 17 48 18 2a  |=pass%..>. ..H.*|
00003040  2a 2a 2a 20 52 65 76 65  72 73 65 20 46 50 20 2a  |*** Reverse FP *|
00003050  2a 2a 2a 0d 17 52 1e 50  75 74 73 20 66 70 20 6e  |***..R.Puts fp n|
00003060  75 6d 62 65 72 20 66 72  6f 6d 20 6d 65 6d 6f 72  |umber from memor|
00003070  79 0d 17 5c 13 69 6e 74  6f 20 76 61 72 69 61 62  |y..\.into variab|
00003080  6c 65 20 60 0d 17 66 0f  dd 20 a4 66 70 28 6d 65  |le `..f.. .fp(me|
00003090  6d 25 29 0d 17 70 0c ea  20 4d 25 2c 20 4e 25 0d  |m%)..p.. M%, N%.|
000030a0  17 7a 07 60 3d 30 0d 17  84 1a 4d 25 20 3d 20 33  |.z.`=0....M% = 3|
000030b0  2b 28 21 26 34 43 30 20  80 20 26 46 46 46 46 29  |+(!&4C0 . &FFFF)|
000030c0  0d 17 8e 0e e3 20 4e 25  3d 30 20 b8 20 34 0d 17  |..... N%=0 . 4..|
000030d0  98 11 4d 25 3f 4e 25 3d  6d 65 6d 25 3f 4e 25 0d  |..M%?N%=mem%?N%.|
000030e0  17 a2 05 ed 0d 17 ac 06  3d 60 0d ff              |........=`..|
000030ec