; Based on Brian Cadge code published Popular Computing Weekly (1984) ; Added support for 664, 6128 and the plus family ; Added support for changing border colors on section boundaries ; Some definitions KL_LOG_EXT: equ 0xbcd1 KL_L_ROM_ENABLE: equ 0xb906 KL_L_ROM_RESTORE: equ 0xb90c KL_NEW_FAST_TICKER: equ 0xbce0 KL_DEL_FAST_TICKER: equ 0xbce6 MC_WAIT_FLYBACK: equ 0xbd19 SCR_SET_MODE: equ 0xbc0e SCR_MODE_CLEAR: equ 0xbdeb RSX_END: equ 0 MAX_MODES: equ 6 EVENT_INSTALLED: equ 0xff EVENT_UNINSTALLED: equ 0 CLASS_NEAR_ADDRESS: equ 0x1 CLASS_EXPRESS_EVENT: equ 0x40 CLASS_ASYNC_EVENT: equ 0x80 org 0xa000 ; Register our RSX commands ld bc, rsx_table ld hl, rsx_four_bytes call KL_LOG_EXT ; Initialize event state ld a, EVENT_UNINSTALLED ld (event_state), a ; Save SCR_MODE_CLEAR vector ld hl, (SCR_MODE_CLEAR + 1) ld (save_smc),hl ; Generate our fake SCR_MODE_CLEAR call install_fake_smc ret rsx_table: dw rsx_names jp setmo jp normal jp smode jp border rsx_names: db "SET", 'M' | 0x80 db "NOR", 'M' | 0x80 db "MOD", 'E' | 0x80 db "BOR", 'D' | 0x80 db RSX_END install_event: ; Change the event state ld a, EVENT_INSTALLED ld (event_state), a ; Initialize the current section number ld a, 0 ld (current_section), a ; Install our event as a fast ticker event ld hl, event_block ld b, CLASS_NEAR_ADDRESS | CLASS_ASYNC_EVENT ld c, 0 ld de, setmo_event call MC_WAIT_FLYBACK jp KL_NEW_FAST_TICKER ; |BORD,section,color ; border: ; border requires an even number of arguments bit 0, a ret nz ; border requires at least two arguments or a ret z border_read_pair_arg: ; Save the number of remaining arguments to process push af ; Get the screen section to modify ld a, (ix + 2) ; There are MAX_MODES sections available, ignore everything else cp MAX_MODES jr nc, border_next_args ; Save the mode for the specified section ld b, 0 ld c, a ld hl, borders_table add hl, bc ex de, hl ld a, (ix + 0) ld hl, basic_to_hw ld c, a add hl, bc ld a, (hl) ld (de), a ; Install events if it is not installed ld a, (event_state) or a call z, install_event border_next_args: ; Restore the number of remaining arguments pairs to process pop af ; Be ready to read next arguments pair inc ix inc ix inc ix inc ix ; One arguments pair less dec a dec a jr nz, border_read_pair_arg ret ; |SETM,section,mode ; The |SETM command is used to set up the various sections of the screen to ; the different modes. The top quarter of the screen is section zero, and the ; bottom quarter is three. The mode number is as normal 0-2. ; ; |SETM can take any number of section settings. For example, to set the top ; quarter of the screen to Mode 0, and the next quarter to Mode 2 you would ; type |SETM,0,0,1,2. ; ; The |SETM command displays the mixed modes, but if you try printing to any ; section the OS still thinks you are in the original mode. See |MODE. setmo: ; setmo requires an even number of arguments bit 0, a ret nz ; setmo requires at least two arguments or a ret z setmo_read_pair_arg: ; Save the number of remaining arguments to process push af ; Get the screen section to modify ld a, (ix + 2) ; There are MAX_MODES sections available, ignore everything else cp MAX_MODES jr nc, setmo_next_args ; Save the mode for the specified section ld b, 0 ld c, a ld hl, modes_table add hl, bc ld a, (ix + 0) ld (hl), a ; Install events if it is not installed ld a, (event_state) or a call z, install_event setmo_next_args: ; Restore the number of remaining arguments pairs to process pop af ; Be ready to read next arguments pair inc ix inc ix inc ix inc ix ; One arguments pair less dec a dec a jr nz, setmo_read_pair_arg setmo_exit: ret setmo_event: ld a, (current_section) ; Save a ld d, a ; Get the mode to apply to the section ld hl, modes_table ld b, 0 ld c, a add hl, bc ld a, (hl) ; Use alternate register set (usually reserved to the firmware) exx ; The screen mode is contained in the first two bytes res 1, c res 0, c or c ld c, a ; B' is used by firmware to store the I/O address of the gate array out (c), c ; Revert back to standard register set exx ; Restore a ld a, d ; Wait for the next HBL because changing border color takes effect ; immediately but changing mode does not rept 23 nop endm ; Change border ld hl, borders_table ld b, 0 ld c, a add hl, bc ld a, (hl) ; Select border color ld bc, 0x7f10 out (c), c ; Change border color add 0x40 out (c), a ; Update current section ld a, (current_section) inc a cp MAX_MODES jr nz, save_section xor a save_section: ld (current_section), a ret ; |NORM,n ; To get back to one mode and disable the fast ticker event, use the |NORM,n ; command. This sets the whole screen to mode 'n'. It is also useful to use ; Normal before the |SETM command as this sets up the mode for any section of ; the screen not included in the |SETM list. normal: ; Disable the fast ticker event ld hl, event_block call KL_DEL_FAST_TICKER ld a, EVENT_UNINSTALLED ld (event_state), a ; Set all modes to the specified mode ld hl, modes_table ld b, MAX_MODES ld a, (ix + 0) normal_all_modes: ld (hl), a inc hl djnz normal_all_modes ; Set the specified mode call SCR_SET_MODE ret ; |MODE,n ; This new command has been added to tell the OS what mode you want to write in. ; 'n' being the Mode number 0 to 2. This command does exactly the same as the ; normal mode command, except that the screen is not cleared. There is no point ; in using mode when the mixed modes are being displayed as any new mode set up ; will be overwritten by the fast ticker event. smode: ; Use our version of SCR_MODE_CLEAR ld hl, fake_smc ld (SCR_MODE_CLEAR + 1), hl ld a, (ix + 0) call SCR_SET_MODE ; Restore SCR_MODE_CLEAR ld hl, (save_smc) ld (SCR_MODE_CLEAR + 1), hl ret ; This code has been replaced since the call works only on CPC 464! ; It is in fact a copy of the SCR_MODE_CLEAR ROM code without the part erasing ; the screen. Fortunately, the routine is the same from the 464 to the 6128+ ; (with the exception of addresses). ;fake_smc: ; call KL_L_ROM_ENABLE ; call 0x0d4f ; ld hl, 0 ; call 0x0b3c ; jp 0x0d3c fake_smc: call KL_L_ROM_ENABLE fake_smc_block1: call 0x0000 ld hl, 0 call 0x0000 fake_smc_block2: jp 0x0000 install_fake_smc: call KL_L_ROM_ENABLE ld hl, (SCR_MODE_CLEAR + 1) ld de, fake_smc_block1 ld bc, 9 ldir ld hl, (SCR_MODE_CLEAR + 1) ld bc, 0x0017 add hl, bc ld de, fake_smc_block2 ld bc, 3 ldir call KL_L_ROM_RESTORE ret ; Current section number current_section: db 0 ; Array of 6 modes number for each 6 sections of the screen (6×1/300 = 1/50) modes_table: db 0, 0, 0, 0, 0, 0 ; Array of 6 borders colors borders_table: db 0, 0, 0, 0, 0, 0 ; Address of the standard SCR_MODE_CLEAR address save_smc: dw 0 ; Event block used by the kernel event_block: db 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ; Four bytes used by the kernel for our RSX rsx_four_bytes: db 0, 0, 0, 0 ; Indicates whether the event is installed or not event_state: db EVENT_UNINSTALLED ; Lookup table to convert Basic colors to hardware colors basic_to_hw: db 0x14, 0x04, 0x15, 0x1c, 0x18, 0x1d, 0x0c, 0x05, 0x0d, 0x16, 0x06, 0x17 db 0x1e, 0x00, 0x1f, 0x0e, 0x07, 0x0f, 0x12, 0x02, 0x13, 0x1a, 0x19, 0x1b db 0x0a, 0x03, 0x0b end