#ifndef __FW_SCR_H__ #define __FW_SCR_H__ #include /** 85: SCR INITIALISE #BBFF Initialize the Screen Pack. Action: Full initialization of the Screen Pack (as used during EMS). All Screen Pack variables and indirections are initialized, also the screen mode and the inks are initialized to their default settings. Entry conditions: No conditions. Exit conditions: AF, BC, DE and HL corrupt. All other registers preserved. Notes: The screen indirections (SCR READ, SCR WRITE and SCR MODE CLEAR) are set to their default routines. The inks are set to their default colours (see Appendix V). The ink flashing periods are set to their default values. The screen is put into mode 1. The screen base is set to put the screen memory at #C000..#FFFF (under the upper ROM. The screen offset is set to 0. The screen is cleared to ink 0. The Graphics VDU write mode is set to FORCE mode. The ink flashing frame flyback event is set up. The initialization is performed in an order that attempts to avoid the previous contents of the screen becoming visible (at EMS the contents will be random). Related entries: GRA INITIALISE SCR RESET TXT INITIALISE */ void fw_scr_initialise(void) __preserves_regs(iyh, iyl); /** 86: SCR RESET #BC02 Reset the Screen Pack. Action: Reinitializes the Screen Pack indirections and the ink colours. Also reinitializes the flash rate and Graphics VDU write mode. Entry conditions: No conditions. Exit conditions: AF, BC, DE and HL corrupt. All other registers preserved. Notes: The screen indirections (SCR READ, SCR WRITE and SCR MODE CLEAR) are set to their default routines. The inks are set to their default colours (see Appendix V). The ink flashing periods are set to their default values. The Graphics VDU write mode is set to FORCE mode. The inks are not passed to the hardware. This will be done when the inks flash next. Related entries: SCR INITIALISE SCR SET ACCESS SCR SET FLASHING SCR SET INK */ void fw_scr_reset(void) __preserves_regs(iyh, iyl); /** 87: SCR SET OFFSET #BC05 Set the offset of the start of the screen. Action: Set the offset of the first character on the screen. By changing this offset the screen can be rolled. Entry conditions: HL contains the required offset. Exit conditions: AF and HL corrupt. All other registers preserved. Notes: The offset passed is masked with #07FE to make sure it is not too big to make sure that the offset is even. (The screen is only capable of rolling in two byte increments). The screen base and screen offset are combined into a single value and sent to the hardware together. The screen offset is used by SCR CHAR POSITION and SCR DOT POSITION to calculate screen addresses. If the screen offset is changed merely by calling the Machine Pack routine MC SCREEN OFFSET then the Text and Graphics VDUs will use incorrect screen addresses. The offset is set to zero when the screen mode is set or the screen is cleared by calling SCR CLEAR. Related entries: MC SCREEN OFFSET SCR GET LOCATION SCR HW ROLL SCR SET BASE SCR SET POSITION */ void fw_scr_set_offset(uint16_t offset) __z88dk_fastcall __preserves_regs(b, c, d, e, iyh, iyl); /** 88: SCR SET BASE #BC08 Set the area of RAM to use for the screen memory. Action: Set the base address of the screen memory. This can be used to move the screen out from underneath the upper ROM or to display a prepared screen instantly. Entry conditions: A contains the more significant byte of the base address. Exit conditions: AF and HL corrupt. All other registers preserved. Notes: The screen memory can only be located on a 16K boundary so the value passed in masked with #C0. The default screen base, set at EMS, is #C0. The screen offset is combined with the screen base into a single value which is sent to the hardware. The screen base address is used by SCR CHAR POSITION and SCR DOT POSITION to calculate screen addresses. If the screen base is changed merely by calling the Machine Pack routine MC SCREEN OFFSET then the text and graphics VDUs will use incorrect screen addresses. The screen memory is not cleared when the screen base is set, use SCR CLEAR to do this. Related entries: MC SCREEN OFFSET SCR GET LOCATION SCR SET OFFSET SCR SET POSITION */ void fw_scr_set_base( uint8_t base_msb) __z88dk_fastcall __preserves_regs(b, c, d, e, iyh, iyl); /** Can be used to decode output of fw_scr_get_location(). */ typedef union fw_scr_screen_location_t { struct { uint16_t offset; uint8_t base_address_msb; uint8_t unused; }; uint32_t as_uint32_t; } fw_scr_screen_location_t; /** WARNING DONE BUT UNTESTED, MIGHT NOT WORK #### CFWI-specific information: #### You can use it like this: fw_scr_screen_location_t screen_location; screen_location.as_uint32_t = fw_scr_get_location(); printf("%d\n", screen_location.offset); printf("%d\n", screen_location.offset); You can also decode offset directly from the uint32_t but don't use that for higher bytes as current version of sdcc generated inefficient Z80 code (even loops in some cases). uint32_t returned_value = fw_scr_get_location(); uint16_t offset = UINT32_SELECT_UINT16(returned_value); uint8_t base_address = UINT32_SELECT_BYTE_2(returned_value); 89: SCR GET LOCATION #BC0B Fetch current base and offset settings. Action: Ask where the screen memory is located and where the start of the screen is. Entry conditions: No conditions. Exit conditions: A contains the more significant byte of the base address. HL contains the current offset. Flags corrupt. All other registers preserved. Notes: The base and offsets returned by this routine may not be the same as those set using SCR SET BASE or SCR SET OFFSET. This is because the values are masked to make them legal and the screen offset is also changed when the hardware screen rolling routine, SCR HW ROLL, is used. Related entries: SCR SET BASE SCR SET OFFSET SCR SET POSITION */ uint32_t fw_scr_get_location(void) __preserves_regs(b, c, iyh, iyl); /** 90: SCR SET MODE #BC0E Set screen into a new mode. Action: Put the screen into a new mode and make sure that the Text and Graphics VDUs are set up correctly. Entry conditions: A contains the required mode. Exit conditions: AF, BC, DE and HL corrupt. All other registers preserved. Notes: The mode requested is masked with #03. If the resulting value is 3 then no action is taken. Otherwise one of the following screen modes is set up: Mode 0: Mode 1: Mode 2: 160 x 200 pixels, 320 x 200 pixels, 640 x 200 pixels, 20 x 25 characters. 40 x 25 characters. 80 x 25 characters. At an early stage the screen is cleared to avoid the old contents of the screen being displayed in the wrong mode. The screen is cleared by calling the SCR MODE CLEAR indirection. All the text and graphics windows are set to cover the whole screen and the graphics user origin is set to the bottom left corner of the screen. The cursor blobs for all text streams are turned off. Stream zero is selected. The current text and graphics pen and paper inks are masked as appropriate for the new mode (see TXT SET PEN et al). When changing mode to a mode that allows fewer inks on the screen this may cause the pen and paper inks to change. Related entries: MC SET MODE SCR GET MODE */ void fw_scr_set_mode(unsigned char x) __z88dk_fastcall __preserves_regs(iyh, iyl); /* 92: SCR CLEAR #BC14 Clear the screen (to ink zero). Action: Clear the whole of screen memory to zero. Entry conditions: No conditions. Exit conditions: AF, BC, DE and HL corrupt. All other registers preserved. Notes: At an early stage the ink flashing is turned off and the inks are all set to the same colour as ink 0. This makes the screen clearing appear instantaneous. When all the screen memory has been set to 0 the ink flashing is turned back on (an ink flashing event is added to the frame flyback queue) and all inks are set to their proper colours. If the text paper ink and graphics paper ink are not set to ink 0 this will become apparent on the screen when characters are written or windows are cleared. The screen offset is set to zero. Related entries: GRA CLEAR WINDOW SCR MODE CLEAR TXT CLEAR WINDOW */ void fw_scr_clear(void) __preserves_regs(iyh, iyl); // void fw_scr_mode_clear(void); /* 102: SCR SET INK #BC32 Set the colours in which to display an ink. Action: Set which two colours will be used to display an ink. If the two colours are the same then the ink will remain a steady colour. If the colours are different then the ink will alternate between these two colours. Entry conditions: A contains an ink number. B contains the first colour. C contains the second colour. Exit conditions: AF, BC, DE and HL corrupt. All other registers preserved. Notes: The ink number is masked with #0F to make sure it is legal, and the colours are masked with #1F. Colours 27..31 are not intended for use; they are merely duplicates of other colours available. The new colours for an ink are not sent to the hardware immediately. They are stored and will appear on the screen when the next frame flyback occurs. The length of time for which each colour is displayed on the screen can be set by calling SCR SET FLASHING. The inks are set to their default colours at EMS and when SCR RESET is called. The various colours available and the default ink colours set are described in Appendix V. Related entries: GRA SET PAPER GRA SET PEN SCR GET INK SCR SET BORDER SCR SET FLASHING TXT SET PAPER TXT SET PEN */ void fw_scr_set_ink( uint8_t pen, uint8_t color1, uint8_t color2 ) __preserves_regs(iyh, iyl); /** 104: SCR SET BORDER #BC38 Set the colours in which to display the border. Action: Set which two colours will be used to display the border. If the two colours are the same then the border will remain a steady colour. If the colours are different then the border will alternate between these two colours. Entry conditions: B contains the first colour. C contains the second colour. Exit conditions: AF, BC, DE and HL corrupt. All other registers preserved. Notes: The colours are masked with #1F to ensure that they are legal. Colours 27..31 are not intended for use; they are merely duplicates of other colours available. The new colours for the border are not sent to the hardware immediately. They are stored and will appear on the screen when the next frame flyback occurs. The length of time for which each colour is displayed on the screen can be set by calling SCR SET FLASHING. The border is set to its default colours at EMS and when SCR RESET is called. The default colour and the colours available are described in Appendix V. Related entries: SCR GET BORDER SCR SET FLASHING SCR SET INK */ void fw_scr_set_border( uint8_t color1, uint8_t color2 ) __preserves_regs(iyh, iyl); #endif /* __FW_SCR_H__ */