CPU-Z80-Disassembler
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t/data/zx48_base.asm view on Meta::CPAN
;; K-CH-SET
K_CH_SET:
ld a,l ; make a copy of the low address byte.
ld hl,0x5C04 ; point to KSTATE-4
; (ld l,$04 would do)
cp l ; have both sets been considered ?
jr nz,K_ST_LOOP ; back to K-ST-LOOP to consider this 2nd set
; now the raw key (0-38d) is converted to a main key (uppercase).
call K_TEST ; routine K-TEST to get main key in A
ret nc ; return if just a single shift
ld hl,0x5C00 ; point to KSTATE-0
cp (hl) ; does the main key code match ?
jr z,K_REPEAT ; forward to K-REPEAT if so
; if not consider the second key map.
ex de,hl ; save kstate-0 in de
ld hl,0x5C04 ; point to KSTATE-4
cp (hl) ; does the main key code match ?
jr z,K_REPEAT ; forward to K-REPEAT if so
; having excluded a repeating key we can now consider a new key.
; the second set is always examined before the first.
bit 7,(hl) ; is the key map free ?
jr nz,K_NEW ; forward to K-NEW if so.
ex de,hl ; bring back KSTATE-0
bit 7,(hl) ; is it free ?
ret z ; return if not.
; as we have a key but nowhere to put it yet.
; continue or jump to here if one of the buffers was free.
;; K-NEW
K_NEW:
ld e,a ; store key in E
ld (hl),a ; place in free location
inc hl ; advance to the interrupt counter
ld (hl),0x05 ; and initialize counter to 5
inc hl ; advance to the delay
ld a,(0x5C09) ; pick up the system variable REPDEL
ld (hl),a ; and insert that for first repeat delay.
inc hl ; advance to last location of state map.
ld c,(iy+0x07) ; pick up MODE (3 bytes)
ld d,(iy+0x01) ; pick up FLAGS (3 bytes)
push hl ; save state map location
; Note. could now have used, to avoid IY,
; ld l,$41; ld c,(hl); ld l,$3B; ld d,(hl).
; six and two threes of course.
call K_DECODE ; routine K-DECODE
pop hl ; restore map pointer
ld (hl),a ; put the decoded key in last location of map.
;; K-END
K_END:
ld (0x5C08),a ; update LASTK system variable.
set 5,(iy+0x01) ; update FLAGS - signal a new key.
ret ; return to interrupt routine.
; -----------------------
; THE 'REPEAT KEY' BRANCH
; -----------------------
; A possible repeat has been identified. HL addresses the raw key.
; The last location of the key map holds the decoded key from the first
; context. This could be a keyword and, with the exception of NOT a repeat
; is syntactically incorrect and not really desirable.
;; K-REPEAT
K_REPEAT:
inc hl ; increment the map pointer to second location.
ld (hl),0x05 ; maintain interrupt counter at 5.
inc hl ; now point to third location.
dec (hl) ; decrease the REPDEL value which is used to
; time the delay of a repeat key.
ret nz ; return if not yet zero.
ld a,(0x5C0A) ; fetch the system variable value REPPER.
ld (hl),a ; for subsequent repeats REPPER will be used.
inc hl ; advance
ld a,(hl) ; pick up the key decoded possibly in another
; context.
; Note. should compare with $A5 (RND) and make
; a simple return if this is a keyword.
; e.g. cp $a5; ret nc; (3 extra bytes)
jr K_END ; back to K-END
; ----------------------
; THE 'KEY-TEST' ROUTINE
; ----------------------
; also called from s-inkey$
; begin by testing for a shift with no other.
;; K-TEST
K_TEST:
ld b,d ; load most significant key to B
; will be $FF if not shift.
ld d,0x00 ; and reset D to index into main table
ld a,e ; load least significant key from E
cp 0x27 ; is it higher than 39d i.e. FF
ret nc ; return with just a shift (in B now)
cp 0x18 ; is it symbol shift ?
jr nz,K_MAIN ; forward to K-MAIN if not
; but we could have just symbol shift and no other
bit 7,b ; is other key $FF (ie not shift)
ret nz ; return with solitary symbol shift
;; K-MAIN
K_MAIN:
ld hl,MAIN_KEYS ; address: MAIN-KEYS
add hl,de ; add offset 0-38
ld a,(hl) ; pick up main key value
scf ; set carry flag
ret ; return (B has other key still)
; ----------------------------------
; THE 'KEYBOARD DECODING' SUBROUTINE
; ----------------------------------
; also called from s-inkey$
;; K-DECODE
K_DECODE:
ld a,e ; pick up the stored main key
cp 0x3A ; an arbitrary point between digits and letters
jr c,K_DIGIT ; forward to K-DIGIT with digits, space, enter.
dec c ; decrease MODE ( 0='KLC', 1='E', 2='G')
jp m,K_KLC_LET ; to K-KLC-LET if was zero
jr z,K_E_LET ; to K-E-LET if was 1 for extended letters.
; proceed with graphic codes.
; Note. should selectively drop return address if code > 'U' ($55).
; i.e. abort the KEYBOARD call.
; e.g. cp 'V'; jr c,addit; pop af ;pop af ;;addit etc. (6 extra bytes).
; (s-inkey$ never gets into graphics mode.)
t/data/zx48_base.asm view on Meta::CPAN
;; K-GRA-DGT
K_GRA_DGT:
ld hl,CTL_CODES-0x30 ; $0230 base address of CTL-CODES
cp 0x39 ; is key '9' ?
jr z,K_LOOK_UP ; back to K-LOOK-UP - changed to $0F, GRAPHICS.
cp 0x30 ; is key '0' ?
jr z,K_LOOK_UP ; back to K-LOOK-UP - changed to $0C, delete.
; for keys '0' - '7' we assign a mosaic character depending on shift.
and 0x07 ; convert character to number. 0 - 7.
add a,0x80 ; add offset - they start at $80
inc b ; destructively test for shift
ret z ; and return if not pressed.
xor 0x0F ; toggle bits becomes range $88-$8F
ret ; return.
; ---
; now digits in 'KLC' mode
;; K-KLC-DGT
K_KLC_DGT:
inc b ; return with digit codes if neither
ret z ; shift key pressed.
bit 5,b ; test for caps shift.
ld hl,CTL_CODES-0x30 ; prepare base of table CTL-CODES.
jr nz,K_LOOK_UP ; back to K-LOOK-UP if shift pressed.
; must have been symbol shift
sub 0x10 ; for ASCII most will now be correct
; on a standard typewriter.
cp 0x22 ; but '@' is not - see below.
jr z,K___CHAR ; forward to K-@-CHAR if so
cp 0x20 ; '_' is the other one that fails
ret nz ; return if not.
ld a,0x5F ; substitute ASCII '_'
ret ; return.
; ---
;; K-@-CHAR
K___CHAR:
ld a,0x40 ; substitute ASCII '@'
ret ; return.
; ------------------------------------------------------------------------
; The Spectrum Input character keys. One or two are abbreviated.
; From $00 Flash 0 to $FF COPY. The routine above has decoded all these.
; | 00 Fl0| 01 Fl1| 02 Br0| 03 Br1| 04 In0| 05 In1| 06 CAP| 07 EDT|
; | 08 LFT| 09 RIG| 0A DWN| 0B UP | 0C DEL| 0D ENT| 0E SYM| 0F GRA|
; | 10 Ik0| 11 Ik1| 12 Ik2| 13 Ik3| 14 Ik4| 15 Ik5| 16 Ik6| 17 Ik7|
; | 18 Pa0| 19 Pa1| 1A Pa2| 1B Pa3| 1C Pa4| 1D Pa5| 1E Pa6| 1F Pa7|
; | 20 SP | 21 ! | 22 " | 23 # | 24 $ | 25 % | 26 & | 27 ' |
; | 28 ( | 29 ) | 2A * | 2B + | 2C , | 2D - | 2E . | 2F / |
; | 30 0 | 31 1 | 32 2 | 33 3 | 34 4 | 35 5 | 36 6 | 37 7 |
; | 38 8 | 39 9 | 3A : | 3B ; | 3C < | 3D = | 3E > | 3F ? |
; | 40 @ | 41 A | 42 B | 43 C | 44 D | 45 E | 46 F | 47 G |
; | 48 H | 49 I | 4A J | 4B K | 4C L | 4D M | 4E N | 4F O |
; | 50 P | 51 Q | 52 R | 53 S | 54 T | 55 U | 56 V | 57 W |
; | 58 X | 59 Y | 5A Z | 5B [ | 5C \ | 5D ] | 5E ^ | 5F _ |
; | 60 £ | 61 a | 62 b | 63 c | 64 d | 65 e | 66 f | 67 g |
; | 68 h | 69 i | 6A j | 6B k | 6C l | 6D m | 6E n | 6F o |
; | 70 p | 71 q | 72 r | 73 s | 74 t | 75 u | 76 v | 77 w |
; | 78 x | 79 y | 7A z | 7B { | 7C | | 7D } | 7E ~ | 7F © |
; | 80 128| 81 129| 82 130| 83 131| 84 132| 85 133| 86 134| 87 135|
; | 88 136| 89 137| 8A 138| 8B 139| 8C 140| 8D 141| 8E 142| 8F 143|
; | 90 [A]| 91 [B]| 92 [C]| 93 [D]| 94 [E]| 95 [F]| 96 [G]| 97 [H]|
; | 98 [I]| 99 [J]| 9A [K]| 9B [L]| 9C [M]| 9D [N]| 9E [O]| 9F [P]|
; | A0 [Q]| A1 [R]| A2 [S]| A3 [T]| A4 [U]| A5 RND| A6 IK$| A7 PI |
; | A8 FN | A9 PNT| AA SC$| AB ATT| AC AT | AD TAB| AE VL$| AF COD|
; | B0 VAL| B1 LEN| B2 SIN| B3 COS| B4 TAN| B5 ASN| B6 ACS| B7 ATN|
; | B8 LN | B9 EXP| BA INT| BB SQR| BC SGN| BD ABS| BE PEK| BF IN |
; | C0 USR| C1 ST$| C2 CH$| C3 NOT| C4 BIN| C5 OR | C6 AND| C7 <= |
; | C8 >= | C9 <> | CA LIN| CB THN| CC TO | CD STP| CE DEF| CF CAT|
; | D0 FMT| D1 MOV| D2 ERS| D3 OPN| D4 CLO| D5 MRG| D6 VFY| D7 BEP|
; | D8 CIR| D9 INK| DA PAP| DB FLA| DC BRI| DD INV| DE OVR| DF OUT|
; | E0 LPR| E1 LLI| E2 STP| E3 REA| E4 DAT| E5 RES| E6 NEW| E7 BDR|
; | E8 CON| E9 DIM| EA REM| EB FOR| EC GTO| ED GSB| EE INP| EF LOA|
; | F0 LIS| F1 LET| F2 PAU| F3 NXT| F4 POK| F5 PRI| F6 PLO| F7 RUN|
; | F8 SAV| F9 RAN| FA IF | FB CLS| FC DRW| FD CLR| FE RET| FF CPY|
; Note that for simplicity, Sinclair have located all the control codes
; below the space character.
; ASCII DEL, $7F, has been made a copyright symbol.
; Also $60, '`', not used in BASIC but used in other languages, has been
; allocated the local currency symbol for the relevant country -
; £ in most Spectrums.
; ------------------------------------------------------------------------
;**********************************
;** Part 3. LOUDSPEAKER ROUTINES **
;**********************************
; Documented by Alvin Albrecht.
; ------------------------------
; Routine to control loudspeaker
; ------------------------------
; Outputs a square wave of given duration and frequency
; to the loudspeaker.
; Enter with: DE = #cycles - 1
; HL = tone period as described next
;
; The tone period is measured in T states and consists of
; three parts: a coarse part (H register), a medium part
( run in 0.600 second using v1.01-cache-2.11-cpan-39bf76dae61 )