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Tracking Money - Spend Watch example
David Andrews [david@polarnet.com] gets the credit for the inspration on this example. Of course it turned out to be a bit harder than I expected to write it - mostly due to the fact that I wanted it to be a full blown wristapp with lots of features yet still fit on the watch. This one also takes advantage of the 'parent' app which allows setting information in the applet without recompiling it.
What was the hardest about this application is making the user interface work and still be intuitive. Once I got past that, coding was just an excercise left to the reader.
There are a lot of tricks in this code to make it fit. I created a lot of subroutines and learned some interesting tricks to reduce code size. It currently sits at 713 bytes and I know how I can get 2 more bytes out of it, but I can't find much more fluff in the code to cut out. If you can find ways to make it smaller, I would be more than happy to hear about them...
You can download the wristapp and set program here
;Name: spend watch
;Version: spend0
;Description: spend watch - by John A. Toebes, VIII
;This keeps track of how much is in one of 7 categories
;
; Press the NEXT/PREV buttons to advance/backup through the categories
; Press the SET button to add/subtract/set/clear the amounts in the categories
; If you press the set button while the action is blinking, it will be carried out, otherwise
; you can cancel the operation.
;
;TIP: Download your watch faster: Download a WristApp once, then do not send it again. It stays in the watch!
;HelpFile: watchapp.hlp
;HelpTopic: 106
;Parent: SpendSet
;****************************************************************************************
;* Copyright (C) 1997 John A. Toebes, VIII *
;* All Rights Reserved *
;* This program may not be distributed in any form without the permission of the author *
;* jtoebes@geocities.com *
;****************************************************************************************
;
; History:
; 31 July 96 - Corrected problem with totals not being recalculated when you reenter
; the wristapp.
;
INCLUDE "WRISTAPP.I"
;
; (1) Program specific constants
;
; We use a few extra bytes here in low memory. Since we can't possibly
; be running while the COMM app is running, we have no chance of
; conflicting with it's use of this memory.
;
BLINK_BUF EQU $5C ; 3 Byte Buffer for the blink routine
; EQU $5D
; EQU $5E
CAT_SAVE EQU $5F ; Temporary counter variable
COUNTER EQU $60 ; Temporary variable to hold the
FLAGBYTE EQU $61
; Bit 0 indicates that the display does not need to be cleared
; The other bits are not used
CURRENT_MODE EQU $62 ; The current mode that we are in
MODE_SELECT EQU 0 ; Set mode, selecting which category to modify
MODE_HUNDREDS EQU 1 ; Set mode, changing the hundreds of dollars digits
MODE_DOLLARS EQU 2 ; Set mode, changing the dollars digits
MODE_CENTS EQU 3 ; Set mode, changing the cents
MODE_ACTION EQU 4 ; Set mode, changing the action
MODE_VIEW EQU 5 ; Normal display mode
CATEGORY EQU $63 ; Current category
;
; These three bytes need to be contiguous. The represent the current
; value that is being operated on
;
HUNDREDS EQU $64
DOLLARS EQU $65
CENTS EQU $66
ACTION EQU $67 ; Selector for the current action
ACT_ADD EQU 0
ACT_SUB EQU 1
ACT_SET EQU 2
ACT_CLEAR EQU 3
AMT_BASE EQU $F0
;
;
; (2) System entry point vectors
;
START EQU *
L0110: jmp MAIN ; The main entry point - WRIST_MAIN
L0113: rts ; Called when we are suspended for any reason - WRIST_SUSPEND
nop
nop
L0116: jmp DO_UPD ; Called to handle any timers or time events - WRIST_DOTIC
L0119: rts ; Called when the COMM app starts and we have timers pending - WRIST_INCOMM
nop
nop
L011c: rts ; Called when the COMM app loads new data - WRIST_NEWDATA
nop
nop
L011f: lda STATETAB0,X ; The state table get routine - WRIST_GETSTATE
rts
L0123: jmp HANDLE_STATE
db STATETAB0-STATETAB0
L0127: jmp HANDLE_STATE
db STATETAB1-STATETAB0
;
; (3) Program strings
;
; These strings represent the 4 possible actions. They need to be early on in the data segment so that
; then can be pointed to by using 8-bit offset addressing. They are exactly 3 bytes long and are
; displayed by using the BLINK_TZONE routine
;
S3_MODE:
S3_ADD timex "ADD"
S3_SUB timex "SUB"
S3_SET timex "SET"
S3_CLR timex "CLR"
;
; These are the categories that the end user has configured. They are set by using the SPENDSET program
; which searches for the first string "TOTAL ". These strings must be exactly 8 bytes each in order with
; total being the first one.
;
S8_TOTAL: timex "TOTAL "
S8_CAT1: timex "CAT1 "
S8_CAT2: timex "CAT2 "
S8_CAT3: timex "CAT3 "
S8_CAT4: timex "CAT4 "
S8_CAT5: timex "CAT5 "
S8_CAT6: timex "CAT6 "
S8_CAT7: timex "CAT7 "
;
; These are the running amounts for each category. Note that you can actually
; initialize them with some default and the code will run properly
;
AMT_TOTAL: db 0,0,0
AMT_CAT1: db 0,0,0
AMT_CAT2: db 0,0,0
AMT_CAT3: db 0,0,0
AMT_CAT4: db 0,0,0
AMT_CAT5: db 0,0,0
AMT_CAT6: db 0,0,0
AMT_CAT7: db 0,0,0
;
; These strings prompt for the current mode that we are in. They are displayed on the top line of
; the display.
;
S6_SELECT timex6 "SELECT"
S6_AMOUNT timex6 "AMOUNT"
S6_ACTION timex6 "ACTION"
S6_SPEND: timex6 "SPEND" ; save a byte by leaching off the space on the start of the next string
S6_WATCH: timex6 " WATCH"
;
; This table selects which string is to be displayed. It is directly indexed by the current mode
;
MSG_TAB db S6_SELECT-START ; 0 - MODE_SELECT
db S6_AMOUNT-START ; 1 - MODE_HUNDREDS
db S6_AMOUNT-START ; 2 - MODE_DOLLARS
db S6_AMOUNT-START ; 3 - MODE_CENTS
db S6_ACTION-START ; 4 - MODE_ACTION
db S6_SPEND-START ; 5 - MODE_VIEW
;
; This is one of the magic tricks for providing the source for the blink routine.
; These are base pointers (offset from HUNDREDS) that we use to copy three bytes into
; BLINK_BUF. The interesting one here is the MODE_CENTS entry which points to DATDIGIT1
; This works because the last number that we format happens to be the cents amount,
; and the blink routine expects the two characters instead of the actual value.
;
DATASRC db HUNDREDS-HUNDREDS ; 1 - MODE_HUNDREDS
db DOLLARS-HUNDREDS ; 2 - MODE_DOLLARS
db DATDIGIT1-HUNDREDS ; 3 - MODE_CENTS
db S3_ADD-HUNDREDS ; 4 - MODE_ACTION 0 - ACT_ADD
db S3_SUB-HUNDREDS ; 4 - MODE_ACTION 1 - ACT_SUB
db S3_SET-HUNDREDS ; 4 - MODE_ACTION 2 - ACT_SET
db S3_CLR-HUNDREDS ; 4 - MODE_ACTION 3 - ACT_CLR
;
; This is the parameter to select which blink routine we want to use
;
BLINK_PARM db BLINK_MID12 ; 1 - MODE_HUNDREDS
db BLINK_MID34 ; 2 - MODE_DOLLARS
db BLINK_SECONDS ; 3 - MODE_CENTS
db BLINK_TZONE ; 4 - MODE_ACTION
;
; (4) State Tables
;
; This set of state tables is a little special since we actually use the
; same state processing routine for both states. This saves us a lot of
; memory but still allows us to let the state table make it easy to exit
; the app with the MODE button
;
STATETAB0:
db 0
db EVT_ENTER,TIM2_12TIC,0 ; Initial state
db EVT_RESUME,TIM_ONCE,0 ; Resume from a nested app
db EVT_TIMER2,TIM_ONCE,0 ; This is the timer
db EVT_MODE,TIM_ONCE,$FF ; Mode button
db EVT_SET,TIM_ONCE,1 ; Set button
db EVT_DNANY4,TIM_ONCE,0 ; NEXT, PREV, SET, MODE button pressed
db EVT_END
STATETAB1:
db 1
db EVT_RESUME,TIM_ONCE,1 ; Resume from a nested app
db EVT_DNANY4,TIM_ONCE,1 ; NEXT, PREV, SET, MODE button pressed
db EVT_UPANY4,TIM_ONCE,1 ; NEXT, PREV, SET, MODE button released
db EVT_USER2,TIM_ONCE,0 ; Return to state 0
db EVT_END ; End of table
;
; (5) Put up the initial banner screen
;
HANDLE_ENTER
clra
sta CATEGORY ; We start out displaying the totals
jsr FETCH_CATEGORY
jsr CLEARALL ; Clear the display
lda #S6_SPEND-START ; Put 'SPEND ' on the top line
jsr PUT6TOP
lda #S6_WATCH-START ; Put ' WATCH' on the second line
jsr PUT6MID
clr FLAGBYTE ; Force us to clear the display
lda #MODE_VIEW ; Start out in the VIEW mode
sta CURRENT_MODE
lda #SYS8_MODE ; Put MODE on the bottom line
jmp PUTMSGBOT
;
; (6) This is the main screen update routine.
;---------------------------------------------------------------
; Routine:
; SHOWCURRENT
; Parameters:
; HUNDREDS,DOLLARS,CENTS - Current value to be displayed
; 0,FLAGBYTE - Screen state (CLR=Must clear it first)
; CATEGORY - the current category to be displayed
; Returns:
; DATDIGIT1,DATDIGIT2 - 2 digit characters for the cents value
; Purpose:
; This routine shows the current selected category and value for the category
;---------------------------------------------------------------
SHOWCURRENT
brset 0,FLAGBYTE,NOCLEAR ; If we don't need to clear the display, skip it
jsr CLEARALL ; Clear the display
bset 0,FLAGBYTE ; And remember that we did it
NOCLEAR
lda #ROW_MP45 ; Turn on the decimal point
sta DISP_ROW
bset COL_MP45,DISP_COL
ldx HUNDREDS ; Get the Hundreds
jsr FMTBLANK0 ; Format it
jsr PUTMID12 ; and display it
;
; We want to output the dollars, but if there were no hundreds, we want to let the
; first digit be a blank. To do this, we simply let it be a blank and set it to a zero
; if there was actually anything in the hundreds field
;
ldx DOLLARS ; Get the Dollars
jsr FMTX ; Format it
tst HUNDREDS ; Do we need to have a leading zero?
beq NOBLANKIT ; No, so it is fine
ldx DOLLARS ; Yes, Get the Dollars again
jsr FMTXLEAD0 ; And format it with a leading zero
NOBLANKIT
jsr PUTMID34 ; Display the Dollars
ldx CENTS ; Get the Cents
jsr FMTXLEAD0 ; Format it (and leave it around for later)
jsr PUTMID56 ; and display it.
lda CATEGORY ; Get which category we want
lsla ; *2
lsla ; *4
lsla ; *8
add #S8_TOTAL-START ; *8+the start of the string
jmp BANNER8 ; and display the right string
;
; (7) State Table 0 and 1 Handler
; This is called to process the state events.
; We see SET, RESUME, DNANY4, and UPANY4 events
;
HANDLE_STATE:
bset 1,APP_FLAGS ; Indicate that we can be suspended
lda BTNSTATE ; Get the event
cmp #EVT_ENTER ; Is this the initial state?
beq HANDLE_ENTER
cmp #EVT_DNANY4 ; How about a button pressed?
beq HANDLE_DNANY
bclr 1,BTNFLAGS ; Turn off the repeat counter
cmp #EVT_SET ; Did they press the set button
bne SKIP2 ; No
clr CURRENT_MODE ; Yes, Go to MODE_SELECT
SKIP2 bra GOREFRESH
;
; (8) They pressed a button, so handle it
;
HANDLE_DNANY
lda BTN_PRESSED ; Let's see what the button they pressed was
beq DO_NEXT ; MODE=1, and NEXT=0, so if it is less, it must be the next button
cmp #EVT_SET ; MODE=1 SET=2 PREV=3, test all at once
blo DO_MODE ; <2 = 1 so we have a EVT_MODE
bhi DO_PREV ; >2 = 3 so we have a EVT_PREV
;
; They pressed the set button, so we want to carry out the operation IF they have
; one currently selected.
;
DO_SETOUT
lda CURRENT_MODE ; See what mode we were in
cmp #MODE_ACTION ; Is it the ACTION mode?
bne NO_ACTION ; No, so just cancel the operation
jsr DO_OPERATION ; Do what they requested
jsr DO_TOTAL ; And total up everything
jsr PLAYCONF ; Plus tell them that we did it
NO_ACTION
bclr 0,FLAGBYTE ; We need to clear the display
lda #MODE_VIEW ; And switch back to VIEW mode
sta CURRENT_MODE
lda #EVT_USER2 ; And go back to state 0
jmp POSTEVENT
;
; (9) This handles the update routine to change a digit...
;
DO_NEXT
bset 0,SYSFLAGS ; Mark our update direction as up
BRSKIP2 ; and skip over the next instruction
DO_PREV
bclr 0,SYSFLAGS ; Mark our update direction as down
DO_UPD
lda CURRENT_MODE ; Which mode are we in?
beq CHANGE_CATEGORY ; 0=MODE_SELECT, so change the category
cmp #MODE_VIEW ; 5=MODE_VIEW, so we also change the category
bne TRYOTHERS
CHANGE_CATEGORY
; (10) updating the category
ldx #CATEGORY ; Point to the category variable
lda #7 ; get our range of values
bsr ADJUST_PX_ANDA ; And let the routine do the adjust for us
jsr FETCH_CATEGORY ; Update the current amount from the new category
GOREFRESH
bra REFRESH
;
; (11) ADJUST_PX_ANDA - a routine to adjust a value based on the direction
;---------------------------------------------------------------
; Routine:
; ADJUST_PX_ANDA
; Parameters:
; A - Binary range to limit value within ((2**x)-1)
; 0,SYSFLAGS - Direction to adjust, SET=UP
; X - Pointer to value to be adjusted
; Returns:
; Value pointed to by X is adjusted
; Purpose:
; This routine adjusts a value up or down based on the current direction, wrapping
; it to the binary range indicated by the value in A. Note that this value must
; be a power of 2-1 (e.g. 1, 3, 7, 15, 31, 63, or 127)
;---------------------------------------------------------------
ADJUST_PX_ANDA
inc ,X
brset 0,SYSFLAGS,NODEC
dec ,X
dec ,X
NODEC and ,X
sta ,X
rts
;
; (12) Try updating one of the other modes
; We have already handled MODE_SELECT and MODE_VIEW. This code handles
; MODE_HUNDREDS, MODE_DOLLARS, MODE_CENTS, and MODE_ACTION
;
TRYOTHERS
cmp #MODE_CENTS ; 3=MODE_CENTS
bls TRYMORE ; If it is <=, then we leave only MODE_ACTION
; (13) updating the Action
lda CATEGORY ; Which category is it?
beq REFRESH ; If we are displaying the total, you can't change the action
ldx #ACTION ; Point to the current action
lda #3 ; and the range of actions
bsr ADJUST_PX_ANDA ; and let our simple routine handle it for us
bra REFRESH
TRYMORE
beq DOCENTS ; If it is MODE_CENTS, go handle it
; (14) Update MODE_HUNDREDS=1 and MODE_DOLLARS=2
clrx ; Set the lower limit =0
stx UPDATE_MIN
ldx #99 ; And the upper limit= 99
stx UPDATE_MAX
add #HUNDREDS-1 ; Point to the right byte to update
tax ; And put it in X as the parameter
lda CURRENT_MODE ; MODE=1 MODE=2
deca ; 0 1
lsla ; 0 2
add #UPD_MID12 ; 5=UPD_MID12 7=UPD_MID34
jsr START_UPDATEP ; And prepare the update routine
bset 4,BTNFLAGS ; Mark that the update is now pending
rts
;
; (15) This is where we switch which digit we are changing...
;
DO_MODE
lda CURRENT_MODE ; Get the mode
ldx #MODE_ACTION ; Limit it to the first 5 modes
jsr INCA_WRAPX ; And let the system increment it for us
sta CURRENT_MODE ; Save it back
; When we switch to the ACTION mode and we have the Totals category showing,
; we need to limit them to the single action of CLEAR
;
cmp #MODE_ACTION ; Did we go to action mode?
bne REFRESH ; No, nothing to do
clr ACTION ; Reset the action to be add
tst CATEGORY ; Are we displaying the totals
bne REFRESH ; No, nothing more to do
lda #ACT_CLEAR ; Yes, switch them to CLEAR
sta ACTION
;
; (16) Refresh the screen and start blinking the current digit...
;
REFRESH
; 0 - SELECT <Category>
; 1 - AMOUNT (Blink hundreds)
; 2 - AMOUNT (Blink dollars)
; 3 - AMOUNT (Blink cents)
; 4 - ACTION
jsr SHOWCURRENT ; Format the screen
ldx CURRENT_MODE ; Get the mode
lda MSG_TAB,X ; So that we can get the message for it
jsr PUT6TOP ; And put that on the top of the display
;
; Now we need to make the right thing blink
;
ldx CURRENT_MODE ; Are we in Select mode?
beq NOBLINK2 ; Yes, don't blink anything
cpx #MODE_ACTION ; How about ACTION MODE?
bhi NOBLINK2 ; >ACTION is VIEW mode, so if so, don't blink either
; 1 -> BLINK_MID12 PARM=&HUNDREDS
; 2 -> BLINK_MID34 PARM=&DOLLARS
; 3 -> BLINK_SECONDS PARM=&2Characters
; 4 -> BLINK_TZONE PARM=&3Characters
brset 1,BTNFLAGS,NOBLINK2 ; Also, we don't want to be blinking if we are in an update routine
bne SETUP_BLINK ; If we were not in action mode, we have the right data source
; Put a > on the display
ldx #C_RIGHTARR ; Put a > sign right in front of the action
lda #POSL3_5
jsr PUTLINE3
lda CURRENT_MODE ; Get the mode
add ACTION ; And add in the action
tax ; To compute our data source pointer
SETUP_BLINK
;
; (17) Set up the parameters for and call the blink routine
;
ldx DATASRC-1,X ; Get the offsetted pointer to the right data
lda HUNDREDS,X ; And copy the 3 bytes to our blink buffer
sta BLINK_BUF
lda HUNDREDS+1,X
sta BLINK_BUF+1
lda HUNDREDS+2,X
sta BLINK_BUF+2
ldx CURRENT_MODE ; Get our mode again
lda BLINK_PARM-1,X ; and use it to pick up which parameter we are passing
ldx #BLINK_BUF ; Point to the common blink buffer
jsr START_BLINKP ; And do it
bset 2,BTNFLAGS ; Mark a blink routine as pending
NOBLINK2
rts
;
; (18) Update MODE_CENTS
; This is a special case since we don't have a system routine that allows updating
; the right most digits on the middle line. Fortunately we can fake it by turning
; on the tic timer and waiting until 8 tics have passed before going into a repeat
; loop. The code has been carefully constructed so that the tic timer can just go
; straight to the DO_UPD code to work.
DOCENTS
ldx #COUNTER ; Point to the counter (saves code size)
brset 1,BTNFLAGS,NOSTART ; Are we already in an update loop?
lda #8 ; No, we need to wait 8 tics
sta ,X ; X->COUNTER ; Save the value
BSET 1,BTNFLAGS ; and start the timer
bra DOIT ; But still do it once right now
;
DEC_DELAY
dec ,X ; X->COUNTER ; We haven't hit the limit, decrement it and try again
rts
NOSTART
tst ,X ; X->COUNTER ; We are in the loop, have we hit the limit?
bne DEC_DELAY ; no, go off and delay once more
DOIT
lda #99 ; Our upper limit is 99
ldx #CENTS ; Point to the cents variable (saves code size)
brset 0,SYSFLAGS,UPCENTS ; Are we in an up mode?
dec ,X ; X->CENTS ; Down, decrement the value
bpl REFRESH ; If we didn't wrap, just go display it
sta ,X ; X->CENTS ; We wrapped, save the upper limit
bra REFRESH ; and go display it
UPCENTS
inc ,X ; X->CENTS ; Up, increment the value
cmp ,X ; X->CENTS ; Did we hit the limit?
bpl REFRESH ; No, go display it
clr ,X ; X->CENTS ; Yes, wrap to the bottom
bra REFRESH ; and display it
;
; (19) DO_OPERATION - Perform the requested operation
;---------------------------------------------------------------
; Routine:
; DO_OPERATION
; Parameters:
; HUNDREDS,DOLLARS,CENTS - Amount to be added/subtracted/set
; CATEGORY - Item to be updated
; ACTION - 0 = ACT_ADD
; 1 = ACT_SUB
; 2 = ACT_SET
; 3 = ACT_CLEAR
; Purpose:
; Adjusts the corresponding category by the given amount
;---------------------------------------------------------------
DO_OPERATION
lda CATEGORY ; Get our category
bsr COMPUTE_BASE ; And point to the data for it
lda ACTION ; Which action is it?
beq DO_ADD ; 0=ADD, go do it
cmp #ACT_SET ; 3 way compare here... (code trick)
beq DO_SET ; 2=SET, go do it
blo DO_SUB ; <2=1 (SUB), go do it
DO_CLR ; >2 = 3 (CLEAR)
clr HUNDREDS ; Clear out the current values
clr DOLLARS
clr CENTS
tst CATEGORY ; Were we clearing the total?
bne DO_SET ; No, just handle it
;
; They want to clear everything
;
ldx #(3*8)-1 ; Total number of categories
CLEAR_TOTALS
; Mini Routine here X=number of bytes to clear
clra
CLR_MORE
sta AMT_TOTAL,X ; Clear out the next byte
decx ; Decrement the number to do
bpl CLR_MORE ; And go for more
rts
;
; (20) Handle Subtracting a value
;
DO_SUB
neg HUNDREDS ; Just negate the value to be added
neg DOLLARS
neg CENTS ; And fall into the add code
;
; (21) Handle Adding a value
;
DO_ADD
lda CENTS ; Add the cents
add AMT_BASE+2,X
sta CENTS
lda DOLLARS ; Add the dollars
add AMT_BASE+1,X
sta DOLLARS
lda HUNDREDS ; Add the hundreds
add AMT_BASE,X
sta HUNDREDS
ldx #CENTS ; Point to the cents as it will be the first one we fix up
tst ACTION ; See what type of operation we just did
beq FIXUP_ADD ; Was it an ADD? If so, do do it
bsr TRYDEC ; Decrement, fix up the Cents
bsr TRYDEC ; Then fix up the dollars
lda HUNDREDS ; Did the hundreds underflow as a result?
bmi DO_CLR ; Yes, so just set everything to zero
bra DO_SET ; No, so copy over the values to the current entry
TRYDEC
lda ,X ; Get the current byte to check
bpl RETDEC ; If it didn't underflow, then skip to the next byte
add #100 ; Add back the 100 that it underflowed
sta ,X ; And save that away
decx ; Back up to the next most significant byte
dec ,X ; and borrow the one
rts
RETDEC decx ; No need to do anything, so skip to the next byte
rts
TRYADD
lda ,X ; Get the current byte to check
sub #100 ; See if it was less than 100
bmi RETDEC ; If so, then it was already normalized so skip out
sta ,X ; It was an overflow, so save the fixed value
decx ; Skip to the next byte
inc ,X ; And add in the overflow
rts
FIXUP_ADD
bsr TRYADD ; Fix up the cents
bsr TRYADD ; and then fix up the dollars
;
; (22) Handle setting a value
;
DO_SET
bsr COMPUTE_CATEGORY_BASE ; Point to the data for our category
lda HUNDREDS ; Copy over the values to the current category
sta AMT_BASE,X
lda DOLLARS
sta AMT_BASE+1,X
lda CENTS
sta AMT_BASE+2,X
rts
;
; (23) COMPUTE_BASE - Computes an offset pointer to get to the total amounts
; This is a trick to save us a few bytes in the instructions.
;---------------------------------------------------------------
; Routine:
; COMPUTE_BASE
; Parameters:
; A - Offset into total
; Returns:
; X - Pointer relative to AMT_BASE to use
; Purpose:
; Computes an offset pointer to get to the total amounts
;---------------------------------------------------------------
COMPUTE_CATEGORY_BASE
lda CATEGORY ; Get our category
COMPUTE_BASE
ldx #3
mul
add #AMT_TOTAL-AMT_BASE
tax
rts
;
; (24) This is the main initialization routine which is called when we first get the app into memory
;
MAIN:
lda #$c0 ; We want button beeps and to indicate that we have been loaded
sta WRISTAPP_FLAGS
; Fall into DO_TOTAL
;
; (25) DO_TOTAL - Recomputes the current total
;---------------------------------------------------------------
; Routine:
; DO_TOTAL
; Parameters:
; NONE
; Purpose:
; Recomputes the current total
;---------------------------------------------------------------
DO_TOTAL
lda CATEGORY ; Remember our category
sta CAT_SAVE
clr ACTION ; Say that we want to add 0=ACT_ADD
clr CATEGORY ; To the total category
ldx #2 ; But we need to clear it first
bsr CLEAR_TOTALS
lda #7 ; And iterate over the 7 categories
sta COUNTER
TOT_LOOP
lda COUNTER ; Get our current category
bsr FETCH_CATEGORY ; And fetch the data
jsr DO_OPERATION ; Then add it to the total
dec COUNTER ; Go to the next category
bne TOT_LOOP ; Until we are done
lda CAT_SAVE ; Restore the category
sta CATEGORY
; fall into FETCH_CATEGORY
; (26) FETCH_CATEGORY - Retrieves the value of the total amount for the selected category
;---------------------------------------------------------------
; Routine:
; FETCH_CATEGORY
; Parameters:
; A - Category to be fetched
; Returns:
; HUNDREDS,DOLLARS,CENTS - Current value of selected category
; Purpose:
; Retrieves the value of the total amount for the selected category
;---------------------------------------------------------------
FETCH_CATEGORY
bsr COMPUTE_BASE ; Get the pointer to the base
lda AMT_BASE,X ; And retrieve the data
sta HUNDREDS
lda AMT_BASE+1,X
sta DOLLARS
lda AMT_BASE+2,X
sta CENTS
rts
;--------------------END OF CODE---------------------------------------------------
This is a pretty significant program and the sections are ordered to make the branches all work out. Here's a quick lookaround at the sections.
- Program specific constants - It is worth noting that in this case, I actually intruded on the space which one might consider reserved for the system applications. However, the only one that uses any of this memory is the Comm app and there is no chance that we need to be running while it is. We are forced in several instances to use this lower memory because the system roms need a pointer passed in X. Since our code loads into 0110 and beyond, we have to use lower memory if we want to actuall point to something.
- System entry point vectors - Nothing really special here. However, we do have a timer routine that we enable when we are inputting cents. What is nice in this case is that the code is constructed so that it jumps right into the processing loop to act as if a timer event had occured with the normal state processing.
- Program strings - We have quite a few strings that we have created. We also take advantage of table of pointers to save us code space.
- State Tables - This is a pretty unusual program in that even though we have two state tables, they both point to the same state table processing routine. This allows me to let the system handle knowing when we are in set mode to allow for the mode button to advance us through states in the set mode and to take us out of the wristapp when we are not in set mode.
- Initial Banner Screen - No real surprises here.
- This is the main screen update routine.
- State Table 0 and 1 Handler
- They pressed a button, so handle it
- This handles the update routine to change a digit...
- updating the category
- ADJUST_PX_ANDA - a routine to adjust a value based on the direction
- Try updating one of the other modes
- updating the Action
- Update MODE_HUNDREDS=1 and MODE_DOLLARS=2
- This is where we switch which digit we are changing...
- Refresh the screen and start blinking the current digit...
- Set up the parameters for and call the blink routine
- Update MODE_CENTS
- DO_OPERATION - Perform the requested operation
- Handle Subtracting a value
- Handle Adding a value
- Handle setting a value
- COMPUTE_BASE - Computes an offset pointer to get to the total amounts
- This is the main initialization routine which is called when we first get the app into memory
- DO_TOTAL - Recomputes the current total
- FETCH_CATEGORY - Retrieves the value of the total amount for the selected category
- Handle the underflows when adding dollars and cents