Move readkey to a separate module

CHANGELOG.md

@@ -14,7 +14,7 @@
 
 * Added `memory_barrier` macro.
 
-* Added `readkey` function.
+* Added `keyboard` module.
 
 * Added `random` module.
 

docs/README.md

@@ -45,7 +45,7 @@
 
 * [Modules for reading input devices](stdlib/input.md)
 
-* [Other cross-platform modules (`err`, `random`)](stdlib/other.md)
+* [Other cross-platform modules (`keyboard`, `err`, `random`)](stdlib/other.md)
 
 * [Definitions available on only some platforms](stdlib/frequent.md)
 

docs/index.md

@@ -45,7 +45,7 @@
 
 * [Modules for reading input devices](stdlib/input.md)
 
-* [Other cross-platform modules (`err`, `random`)](stdlib/other.md)
+* [Other cross-platform modules (`keyboard`, `err`, `random`)](stdlib/other.md)
 
 * [Definitions available on only some platforms](stdlib/frequent.md)
 

docs/stdlib/frequent.md

@@ -29,26 +29,6 @@ Moves the cursor to the next line.
 Available for: all computer targets.  
 Uses ROM routines, so requires the appropriate ROM to be enabled if applicable.
 
-#### `byte readkey()`
-
-Waits for and reads a single keypress.
-
-The returning values may vary between platforms:
-
-* letters may be uppercase or lowercase
-
-* modifier keys may be applied or ignored
-
-Available for:
-Commodore 64 (requires KERNAL),
-Commodore 16 or Plus/4 (requires KERNAL),
-Commodore 128 (requires KERNAL),
-VIC 20 (requires KERNAL),
-Atari,
-Amstrad CPC,
-ZX Spectrum,
-NEC PC-88.
-
 #### `pointer readline()`
 
 Reads a line from the console and returns a pointer to a null-terminated string.

docs/stdlib/other.md

@@ -1,5 +1,34 @@
 [< back to index](../index.md)
 
+## keyboard
+
+The `keyboard` module provides support for reading keypresses from the keyboard.
+Not supported on all targets.
+
+#### `byte readkey()`
+
+Waits for and reads a single keypress.
+
+The returning values may vary between platforms:
+
+* letters may be uppercase or lowercase
+
+* modifier keys may be applied or ignored
+
+Available for:
+Commodore 64 (requires KERNAL),
+Commodore 16 or Plus/4 (requires KERNAL),
+Commodore 128 (requires KERNAL),
+VIC 20 (requires KERNAL),
+Atari,
+Amstrad CPC,
+ZX Spectrum,
+NEC PC-88.
+
+#### `const byte KEY_ENTER`
+
+Key code for the Enter/Return key. Usually 13, but not always.
+
 ## err
 
 #### `enum error_number`

examples/crossplatform/guess.mfk

@@ -10,7 +10,11 @@ import c64_basic
 import c264_basic
 #endif
 
-#define READKEY = CBM_64 | CBM_VIC | CBM_264 | CBM_128 | ZX_SPECTRUM | NEC_PC_88 | ATARI_8
+#define READKEY = CBM_64 | CBM_264 | ZX_SPECTRUM | NEC_PC_88
+
+#if READKEY
+import keyboard
+#endif
 
 void main () {
     init_rand_seed()

include/a8_kernel.mfk

@@ -13,16 +13,6 @@ noinline asm void putchar(byte a) {
     rts
 }
 
-noinline asm byte readkey() {
-    lda #$C
-    sta $2A
-    lda $E425
-    pha
-    lda $E424
-    pha
-    rts
-}
-
 inline void new_line() {
     putchar($9b)
 }

include/c128_kernal.mfk

@@ -15,14 +15,6 @@ asm void putchar(byte a) {
     ? RTS
 }
 
-noinline asm byte readkey() {
-__read_key__start:
-    LDA $D0
-    BEQ __read_key__start
-    LDX #0
-    JMP $C244
-}
-
 inline void new_line() {
     putchar(13)
 }

include/c264_kernal.mfk

@@ -14,14 +14,6 @@ asm void putchar(byte a) {
     ? RTS
 }
 
-noinline asm byte readkey() {
-__read_key__start:
-    LDA $EF
-    BEQ __read_key__start
-    LDX #0
-    JMP $D8D5
-}
-
 inline void new_line() {
     putchar(13)
 }

include/c64_kernal.mfk

@@ -31,13 +31,6 @@ asm void putchar(byte a) {
     ? RTS
 }
 
-noinline asm byte readkey() {
-__read_key__start:
-    LDA $C6
-    BEQ __read_key__start
-    JMP $E5B4
-}
-
 inline void new_line() {
     chrout(13)
 }

include/cpc.mfk

@@ -5,8 +5,6 @@
 
 asm void putchar(byte a) @$BB5A extern
 
-asm byte readkey() @$BB06 extern
-
 inline void new_line() {
     putchar(13)
     putchar(10)

include/keyboard.mfk

@@ -0,0 +1,101 @@
+#if ATARI_8
+const byte KEY_ENTER = 155
+#else
+const byte KEY_ENTER = 13
+#endif
+
+
+#if CBM_64
+noinline asm byte readkey() {
+__read_key__start:
+    LDA $C6
+    BEQ __read_key__start
+    JMP $E5B4
+}
+#define OK = 1
+#endif
+
+
+#if CBM_128
+noinline asm byte readkey() {
+__read_key__start:
+    LDA $D0
+    BEQ __read_key__start
+    LDX #0
+    JMP $C244
+}
+#define OK = 1
+#endif
+
+
+#if CBM_264
+noinline asm byte readkey() {
+__read_key__start:
+    LDA $EF
+    BEQ __read_key__start
+    LDX #0
+    JMP $D8D5
+}
+#define OK = 1
+#endif
+
+
+#if CBM_VIC
+noinline asm byte readkey() {
+__read_key__start:
+    LDA $C6
+    BEQ __read_key__start
+    JMP $E5CF
+}
+#define OK = 1
+#endif
+
+
+#if ATARI_8
+noinline asm byte readkey() {
+    lda #$C
+    sta $2A
+    lda $E425
+    pha
+    lda $E424
+    pha
+    rts
+}
+#define OK = 1
+#endif
+
+
+#if NEC_PC_88
+asm byte readkey() @$3583 extern
+#define OK = 1
+#endif
+
+
+#if AMSTRAD_CPC
+asm byte readkey() @$BB06 extern
+#define OK = 1
+#endif
+
+
+#if ZX_SPECTRUM
+#pragma zilog_syntax
+asm byte readkey() {
+    ld hl,23560
+    ld (hl),0
+__readkey__start:
+    ld a,(hl)
+    or a
+    jr z,__readkey__start
+    ? ret
+}
+#define OK = 1
+#endif
+
+
+#if not(OK)
+    #if KEYBOARD
+        #warn keyboard module is not yet supported
+    #else
+        #warn keyboard module is not supported on targets without keyboard
+    #endif
+#endif

include/pc88.mfk

@@ -6,8 +6,6 @@
 
 asm void putchar(byte a) @$3e0d extern
 
-asm byte readkey() @$3583 extern
-
 inline void new_line() {
     putchar(13)
     putchar(10)

include/vic20_kernal.mfk

@@ -15,13 +15,6 @@ asm void putchar(byte a) {
     ? RTS
 }
 
-noinline asm byte readkey() {
-__read_key__start:
-    LDA $C6
-    BEQ __read_key__start
-    JMP $E5CF
-}
-
 inline void new_line() {
     putchar(13)
 }

include/zxspectrum.mfk

@@ -14,16 +14,6 @@ inline void new_line() {
     putchar(13)
 }
 
-asm byte readkey() {
-    ld hl,23560
-    ld (hl),0
-__readkey__start:
-    ld a,(hl)
-    or a
-    jr z,__readkey__start
-    ? ret
-}
-
 inline asm void set_border(byte a) {
     out (254),a
     ? ret