new memory and project layout

boot.asm

@@ -1,11 +1,9 @@
 STACK_TOP = 0xFFFF
 DELAY_LOOPS_PER_MS = 40
-MONITOR_BASE = 0xC000
-MONITOR_ROM_SOURCE = 0x0080
-TINYBASIC_BASE = 0xD000
-TINYBASIC_ROM_SOURCE = 0x1000
+RESIDENT_BASE = 0xC000
+RESIDENT_ROM_SOURCE = 0x0080
 
-        .include "tinybasic.inc"
+        .include "bios.inc"
 
         .globl _main
         .globl _delay_ms
@@ -14,9 +12,11 @@ TINYBASIC_ROM_SOURCE = 0x1000
         .globl _enable_interrupts
         .globl _disable_interrupts
         .globl _jump_to
-        .globl _monitor_uart_putc
-        .globl _monitor_uart_getc
-        .globl monitor_image_end
+        .globl _bios_putc
+        .globl _bios_try_getc
+        .globl _bios_getc
+        .globl _bios_init
+        .globl resident_image_end
         .globl s__DATA
         .globl l__DATA
         .globl s__INITIALIZER
@@ -31,50 +31,56 @@ TINYBASIC_ROM_SOURCE = 0x1000
 boot_copy:
         di
         ld sp, #STACK_TOP
-        ld hl, #MONITOR_ROM_SOURCE
-        ld de, #MONITOR_BASE
-        ld bc, #(monitor_image_end - MONITOR_BASE)
-        ldir
-
-        ld hl, #TINYBASIC_ROM_SOURCE
-        ld de, #TINYBASIC_BASE
-        ld bc, #TINYBASIC_SIZE
+        ld hl, #RESIDENT_ROM_SOURCE
+        ld de, #RESIDENT_BASE
+        ld bc, #(resident_image_end - RESIDENT_BASE)
         ldir
         jp init
 
 .area _ITABLE (ABS)
 
 ; The executable vector page is part of the image copied to high RAM.
-.org MONITOR_BASE
+.org RESIDENT_BASE
         jp init
-.org MONITOR_BASE + 0x08
+.org RESIDENT_BASE + 0x08
         reti
-.org MONITOR_BASE + 0x10
+.org RESIDENT_BASE + 0x10
         reti
-.org MONITOR_BASE + 0x18
+.org RESIDENT_BASE + 0x18
         reti
-.org MONITOR_BASE + 0x20
+.org RESIDENT_BASE + 0x20
         reti
-.org MONITOR_BASE + 0x28
+.org RESIDENT_BASE + 0x28
         reti
-.org MONITOR_BASE + 0x30
+.org RESIDENT_BASE + 0x30
         reti
-.org MONITOR_BASE + 0x38
+.org RESIDENT_BASE + 0x38
         reti
 
 ; IM 2 table: the CTC supplies vectors 40, 42, 44, and 46.
-.org MONITOR_BASE + 0x40
+.org RESIDENT_BASE + 0x40
         .dw ctc_isr          ; CTC channel 0: vector 0x40
         .dw ctc_isr          ; CTC channel 1: vector 0x42
         .dw ctc_isr          ; CTC channel 2: vector 0x44
         .dw uart_isr         ; CTC channel 3: vector 0x46
 
-; Stable entry points for programs living alongside the monitor.
-; C050: write the character in A. C053: return a character in A, or 0.
-.org MONITOR_BASE + 0x50
-        jp monitor_service_putc
-.org MONITOR_BASE + 0x53
-        jp monitor_service_getc
+; Stable BIOS jump table for ROM-resident applications.
+; C050 putc(A), C053 try_getc(), C056 getc(), C059 io_out(A,L),
+; C05C io_in(A), C05F delay_ms(HL), C062 monitor warm start.
+.org BIOS_PUTC
+        jp bios_service_putc
+.org BIOS_TRY_GETC
+        jp bios_service_try_getc
+.org BIOS_GETC
+        jp bios_service_getc
+.org BIOS_IO_OUT
+        jp bios_service_io_out
+.org BIOS_IO_IN
+        jp bios_service_io_in
+.org BIOS_DELAY_MS
+        jp bios_service_delay_ms
+.org BIOS_MONITOR
+        jp init
 
 .area _HOME
 init:
@@ -87,6 +93,7 @@ init:
         ld a, #0xC0
         ld i, a
         im 2
+        call _bios_init
         call _main
 
 hang:
@@ -124,20 +131,19 @@ clear_loop:
 gsinit_done:
 .area _GSFINAL
         ret
-monitor_image_end:
+resident_image_end:
 
 .area _CODE
 
-; Monitor ABI services preserve all working registers. PUTC also preserves AF;
-; GETC returns the received byte (or zero) in A.
-monitor_service_putc:
+; BIOS ABI services preserve registers except documented return values.
+bios_service_putc:
         push    af
         push    bc
         push    de
         push    hl
         push    ix
         push    iy
-        call    _monitor_uart_putc
+        call    _bios_putc
         pop     iy
         pop     ix
         pop     hl
@@ -146,13 +152,13 @@ monitor_service_putc:
         pop     af
         ret
 
-monitor_service_getc:
+bios_service_try_getc:
         push    bc
         push    de
         push    hl
         push    ix
         push    iy
-        call    _monitor_uart_getc
+        call    _bios_try_getc
         pop     iy
         pop     ix
         pop     hl
@@ -160,6 +166,66 @@ monitor_service_getc:
         pop     bc
         ret
 
+bios_service_getc:
+        push    bc
+        push    de
+        push    hl
+        push    ix
+        push    iy
+        call    _bios_getc
+        pop     iy
+        pop     ix
+        pop     hl
+        pop     de
+        pop     bc
+        ret
+
+bios_service_io_out:
+        push    af
+        push    bc
+        push    de
+        push    hl
+        push    ix
+        push    iy
+        call    _io_out
+        pop     iy
+        pop     ix
+        pop     hl
+        pop     de
+        pop     bc
+        pop     af
+        ret
+
+bios_service_io_in:
+        push    bc
+        push    de
+        push    hl
+        push    ix
+        push    iy
+        call    _io_in
+        pop     iy
+        pop     ix
+        pop     hl
+        pop     de
+        pop     bc
+        ret
+
+bios_service_delay_ms:
+        push    af
+        push    bc
+        push    de
+        push    hl
+        push    ix
+        push    iy
+        call    _delay_ms
+        pop     iy
+        pop     ix
+        pop     hl
+        pop     de
+        pop     bc
+        pop     af
+        ret
+
 .macro MAKE_ISR entry, handler
         .globl handler
 entry: