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fix many problems with new keyboard scan routine

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This commit is contained in:
Paul Gardner-Stephen committed 2019-04-20 01:46:21 +09:30
1 parent 054913ed06
commit 1e37babbb7
3 files changed
+30 -138
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c64/kernal/cint.s
+2 -1
View File
@@ -16,10 +16,11 @@ cint:
;; Set initial variables for our improved keyboard scan routine
lda #$ff
ldx #7
ldx #6
* sta BufferOld,x
dex
bpl -
sta BufferQuantity
;; Set key repeat delay (Compute's Mapping the 64 p215)
;; Making some numbers up here: Repeat every ~1/10th sec
c64/kernal/irq_handler.s
-9
View File
@@ -28,13 +28,4 @@ default_irq_handler:
jsr blink_cursor
jsr scan_keyboard
lda KeyQuantity
sta $0400
lda Buffer+0
sta $0401
lda Buffer+1
sta $0402
lda Buffer+2
sta $0403
jmp return_from_interrupt
c64/kernal/scan_keyboard.s
+28 -128
View File
@@ -11,27 +11,6 @@
;; By: TWW/CTR
;; Preparatory Settings
;; ~~~~~~~~~~~~~~~~~~~~
;; None
;; Destroys
;; ~~~~~~~~
;; Accumulator
;; X-Register
;; Y-Register
;; Carry / Zero / Negative
;; $dc00
;; $dc01
;; $50-$5f
;; Footprint
;; ~~~~~~~~~
;; #$206 Bytes
;; Information
;; ~~~~~~~~~~~
;; The routine uses "2 Key rollower" or up to 3 if the key-combination doesen't induce shadowing.
@@ -40,91 +19,9 @@
;; SHIFT LOCK is not detected due to unreliability.
;; Usage
;; ~~~~~
;; Example Code:
;; jsr Keyboard
;; bcs NoValidInput
;; stx TempX
;; sty TempY
;; cmp #$ff
;; beq NoNewAphanumericKey
;; // Check A for Alphanumeric keys
;; sta $0400
;; NoNewAphanumericKey:
;; // Check X & Y for Non-Alphanumeric Keys
;; ldx TempX
;; ldy TempY
;; stx $0401
;; sty $0402
;; NoValidInput: // This may be substituted for an errorhandler if needed.
;; Returned
;; ~~~~~~~~
;; +=================================================+
;; | Returned in Accumulator |
;; +===========+===========+=============+===========+
;; | $00 - @ | $10 - p | $20 - SPC | $30 - 0 |
;; | $01 - a | $11 - q | $21 - | $31 - 1 |
;; | $02 - b | $12 - r | $22 - | $32 - 2 |
;; | $03 - c | $13 - s | $23 - | $33 - 3 |
;; | $04 - d | $14 - t | $24 - | $34 - 4 |
;; | $05 - e | $15 - u | $25 - | $35 - 5 |
;; | $06 - f | $16 - v | $26 - | $36 - 6 |
;; | $07 - g | $17 - w | $27 - | $37 - 7 |
;; | $08 - h | $18 - x | $28 - | $38 - 8 |
;; | $09 - i | $19 - y | $29 - | $39 - 9 |
;; | $0a - j | $1a - z | $2a - * | $3a - : |
;; | $0b - k | $1b - | $2b - + | $3b - ; |
;; | $0c - l | $1c - £ | $2c - , | $3c - |
;; | $0d - m | $1d - | $2d - - | $3d - = |
;; | $0e - n | $1e - ^ | $2e - . | $3e - |
;; | $0f - o | $1f - <- | $2f - / | $3f - |
;; +-----------+-----------+-------------+-----------+
;; +================================================================================
;; | Return in X-Register |
;; +=========+=========+=========+=========+=========+=========+=========+=========+
;; | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
;; +---------+---------+---------+---------+---------+---------+---------+---------+
;; | CRSR UD | F5 | F3 | F1 | F7 | CRSR RL | RETURN |INST/DEL |
;; +---------+---------+---------+---------+---------+---------+---------+---------+
;; +================================================================================
;; | Return in Y-Register |
;; +=========+=========+=========+=========+=========+=========+=========+=========+
;; | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
;; +---------+---------+---------+---------+---------+---------+---------+---------+
;; |RUN STOP | L-SHIFT | C= | R-SHIFT |CLR/HOME | CTRL | | |
;; +---------+---------+---------+---------+---------+---------+---------+---------+
;; CARRY:
;; - Set = Error Condition (Check A for code):
;; A = #$01 => No keyboard activity is detected.
;; A = #$02 => Control Port #1 Activity is detected.
;; A = #$03 => Key Shadowing / Ghosting is detected.
;; A = #$04 => 2 or 3 new keys is detected within one scan
;; A = #$05 => Awaiting "No Activity" state
;; - Clear = Valid input
;; A = #$ff => No new Alphanumeric Keys detected (some key(s) being held down AND/OR some Non-Alphanumeric key is causing valid return).
;; A <> #$ff => New Alphanumeric Key returned. Non-Alphanumeric keys may also be returned in X or Y Register
;; Issues/ToDo:
;; ~~~~~~~~~~~~
;; - None
;; Improvements:
;; ~~~~~~~~~~~~~
;; - Replace the subroutine with a pseudocommand and account for speedcode parameter (Memory vs. Cycles).
;; - Shorten the routine / Optimize if possible.
;; History:
;; ~~~~~~~~
;; V3.0 - Hacked to pieces by PGS to work as KERNAL keyboard scan routine
;; V2.5 - New test tool.
;; Added return of error codes.
;; Fixed a bug causing Buffer Overflow.
@@ -139,9 +36,6 @@
;; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
;; .pc = * "Keyboard Scan Routine"
;; // ZERO PAGE Varibles
;; $250-$258 is the 81st - 88th characters in BASIC input, a carry over from VIC-20
;; and not used on C64, so safe for us to use, probably.
@@ -152,14 +46,13 @@
.alias BufferNew $A9 ;// 3 bytes
.alias KeyQuantity $A8 ;// 1 byte
.alias TempZP $B6 ;// 1 byte
.alias SimultaneousKeys $F7 ;// 1 byte
;; Reuse RS232 variables, since they should not be used
;; by other things
;; These are initialised in cinit all to $FF
.alias BufferOld $293 ; 3 bytes
.alias Buffer $297 ; 4 bytes
.alias BufferQuantity $29B ; 1 byte
.alias BufferQuantity $B4 ; 1 byte
@@ -175,7 +68,12 @@ scan_keyboard:
;; Work out what is new and needs to be added
;; to the input buffer.
;; Also update the bucky key status flags etc
cmp #$ff
beq +
;; Got a key, turn it from matrix position to key value,
;; and stuff it in the keyboard buffer
*
rts
@@ -227,7 +125,8 @@ OverFlow:
pla
pla
;// Don't manipulate last legal buffer as the routine will fix itself once it gets valid input again.
sec
sec
lda #$ff
rts
@@ -240,7 +139,8 @@ NoActivityDetected:
stx BufferOld
stx BufferOld+1
stx BufferOld+2
sec
sec
lda #$ff
rts
@@ -249,7 +149,8 @@ NoActivityDetected:
ControlPort:
;; // Exit with A = #$02, Carry Set. Keep BufferOld to verify input after Control Port activity ceases
sec
sec
lda #$ff
rts
@@ -312,18 +213,13 @@ skip0:
stx BufferNew+1
stx BufferNew+2
;; // Reset Non-AlphaNumeric Flag
;; Make X = $00, assumed below
inx
;; // Set max keys allowed before ignoring result
lda #MaxKeyRollover
sta KeyQuantity
;; // Counter to check for simultaneous alphanumeric key-presses
lda #$fe
sta SimultaneousKeys
;; //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;; // Check and flag Non Alphanumeric Keys
@@ -428,7 +324,7 @@ skip0:
;; //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;; // Key Scan Completed
;; // Put any new key (not in old scan) into buffer
;; // Put any new key (not in old scan) into buffer
ldx #MaxKeyRollover-1
* lda BufferNew,x
cmp #$ff
@@ -439,13 +335,15 @@ skip0:
beq Exist
cmp BufferOld+2
beq Exist
;; // New Key Detected
inc BufferQuantity
ldy BufferQuantity
sta Buffer,y
;; // Keep track of how many new Alphanumeric keys are detected
inc SimultaneousKeys
beq TooManyNewKeys
;; // New Key Detected
ldy BufferQuantity
cpy #MaxKeyRollover
bcc TooManyNewKeys
iny
sty BufferQuantity
sta Buffer,y
Exist:
dex
bpl -
@@ -478,6 +376,8 @@ Return: ;; // A is preset
rts
TooManyNewKeys:
sec
sec
lda #$ff
sta BufferQuantity
rts