@nataliapc/mcp-openmsx

# MSX 2 SUBROM BIOS Entries ## MSX 2 SUBROM BIOS Entries These are additional BIOS routines which are available in the MSX 2 standard. No new subrom calls were introduced on the MSX 2+ / turbo R. They are located in the so-called SUBROM, which is an alternate BIOS page, switched when necessary. You can call the SUBROM by putting the jump address in register IX and then calling the BIOS routine `EXTROM` (#15F) or `SUBROM` (#15C). Please note that officially it is illegal to call the SUBROM using `CALSLT` because this will cause trouble with some DiskROMs. Therefore, it cannot be called directly from MSX-DOS environment. There is a workaround for that though, which is described in [this article](#msxdocs://bios/Calling_BIOS_from_MSX-DOS). * [Basic calls](#basic-calls) * [Double BIOS calls](#double-bios-calls) * [MSX 2 specific calls](#msx-2-specific-calls) * [Palette-functions](#palette-functions) * [BIT-BLIT routines](#bit-blit-routines) ### BASIC calls #### PAINT (Basic!) ``` Address : #0069 Function : Paints graphical screen Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### PSET (Basic!) ``` Address : #006D Function : Sets a point Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### ATRSCN (Basic!) ``` Address : #0071 Function : Scans color attribute Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### GLINE (Basic!) ``` Address : #0075 Function : Draws a line Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### DOBOXF (Basic!) ``` Address : #0079 Function : Draws a filled box Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### DOLINE (Basic!) ``` Address : #007D Function : Draws a line Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### BOXLIN (Basic!) ``` Address : #0081 Function : Draws a box Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### DOGRPH ``` Address : #0085 Function : Draws a line Input : BC, HL are start coordinates GXPOS, GYPOS are end-coordinates ATRBYT for attribute LOGOPR for logical operator Registers: AF ``` #### GRPPRT ``` Address : #0089 Function : Places a character on graphic screen Input : A - Character ATRBYT for attribute LOGOPR for logical operator ``` #### SCALXY ``` Address : #008D Function : Clip coordinates (till border of screen) Input : BC - X-position DE - Y-position Output : BC - X-position bordered DE - Y-position bordered Registers: AF ``` #### MAPXYC ``` Address : #0091 Function : Converts an X,Y position to an address: and mask in CLOC and CMASK Input : BC - X-position DE - Y-position Output : HL - VRAM address: In SCREEN 3 (in CLOC too) A - Mask In SCREEN 3 (in CMASK too) HL - X-position In SCREEN 5->8 (in CLOC too) A - Y-position In SCREEN 5->8 (in CMASK too) Registers: F ``` #### READC ``` Address : #0095 Function : Reads attribute of pixel Input : X-position in CLOC Y-position in CMASK Output : A - the attribute Registers: AF ``` #### SETATR ``` Address : #0099 Function : Set attribute in ATRBYT Input : A - attribute Output : C-flag set if attribute is wrong Registers: F ``` #### SETC ``` Address : #009D Function : Set attribute of pixel Input : X-position in CLOC Y-position in CMASK Attribute-byte in ATRBYT Registers: AF ``` #### TRIGHT ``` Address : #00A1 Function : Moves pixel to the right Input : X-position in CLOC Yposition in CMASK Output : New X-position in CLOC New Y-position in CMASK C-flag set if border of screen is reached Registers: AF Remark : SCREEN 3 only ``` #### RIGHTC ``` Address : #00A5 Function : Moves pixel to the right Input : See TRIGHT Output : See TRIGHT (except for the C-flag remark) Registers: AF Remark : SCREEN 3 only ``` #### TLEFTC ``` Address : #00A9 Function : Moves pixel to the left Input : See TRIGHT Output : See TRIGHT Registers: AF ``` #### LEFTC ``` Address : #00AD Function : Moves pixel to the left Input : See RIGHTC Output : See RIGHTC Registers: AF Remark : SCREEN 3 only ``` #### TDOWNC ``` Address : #00B1 Function : Moves pixel down Input : See TRIGHT Output : See TRIGHT Registers: AF ``` #### DOWNC ``` Address : #00B5 Function : Moves pixel down Input : See RIGHTC Output : See RIGHTC Registers: AF Remark : SCREEN 3 only ``` #### TUPC ``` Address : #00B9 Function : Moves pixel up Input : See TRIGHT Output : See TRIGHT Registers: AF ``` #### UPC ``` Address : #00BD Function : Moves pixel up Input : See RIGHTC Output : See RIGHTC Registers: AF Remark : SCREEN 3 only ``` #### SCANR ``` Address : #00C1 Function : Scans pixels to the right Input : B - 'Suspend'-flag C - Border-counting Output : DE - Border-counting C - 'Pixel-changed'-flag Registers: All ``` #### SCANL ``` Address : #00C5 Function : Scans pixels to the left Input : DE - Border-counting Output : DE - Border-counting C - 'Pixel-changed'-flag Registers: All ``` #### NVBXLN ``` Address : #00C9 Function : Draws a box Input : BC - X start-position DE - Y-start-position X end-position in GXPOS Y-end-position in GYPOS Attribute in ATRBYT Logical operator in LOGOPR Registers: All ``` #### NVBXFL ``` Address : #00CD Function : Draws a filled box Input : See NVBXLN Registers: All ``` ### Double BIOS calls The following routines are called from the equally named calls in the MAIN ROM, and therefor the input and results will not be shown, nor will the register changes. For that, refer to the corresponding call in the MSX1-BIOS. #### CHGMOD ``` Address : #00D1 Function : Switches to given screenmode ``` #### INITXT ``` Address : #00D5 Function : Switches to SCREEN 0 ``` #### INIT32 ``` Address : #00D9 Function : Switches to SCREEN 1 ``` #### INIGRP ``` Address : #00DD Function : Switches to SCREEN 2 ``` #### INIMLT ``` Address : #00E1 Function : Switches to SCREEN 3 ``` #### SETTXT ``` Address : #00E5 Function : Switches VDP in SCREEN 0 ``` #### SETT32 ``` Address : #00E9 Function : Switches VDP in SCREEN 1 ``` #### SETGRP ``` Address : #00ED Function : Switches VDP in SCREEN 2 ``` #### SETMLT ``` Address : #00F1 Function : Switches VDP in SCREEN 3 ``` #### CLRSPR ``` Address : #00F5 Function : Initialises sprite tables ``` #### CALPAT ``` Address : #00F9 Function : Returns address of sprite pattern-table ``` #### CALATR ``` Address : #00FD Function : Returns address of sprite attribute-table ``` #### GSPSIZ ``` Address : #0101 Function : Returns current sprite-size ``` ### MSX 2 specific calls #### GETPAT ``` Address : #0105 Function : Returns current pattern of a character Input : A - ASCII code of character Output : Pattern in PATWRK starting from address #FC40 Registers: All Remark : Same as routine in MSX1-BIOS, but there is doesn't exist as a BIOS-call ``` #### WTRVRM ``` Address : #0109 Function : Writes data in VRAM (#0000 - #ffff) Input : HL - Address A - Value Registers: AF ``` #### RDVRM ``` Address : #010D Function : Reads content in VRAM (#0000 - #ffff) Input : HL - Address Output : A - Read value Registers: AF ``` #### CHGCLR ``` Address : #0111 Function : Changes screen colors Input : A - Screenmode See MSX1BIOS.HTM (CHGCLR) Registers: All ``` #### CLS ``` Address : #0115 Function : Clear screen Registers: All ``` #### CLRTXT ``` Address : #0119 Function : Clear Text-screen Registers: All ``` #### DSPFNK ``` Address : #011D Function : Display the function keys Registers: All ``` #### DELLNO ``` Address : #0121 Function : Remove line in text screen Input : L - Line Number Registers: All ``` #### INSLNO ``` Address : #0125 Function : Add line to text screen Input : L - Line Number Registers: All ``` #### PUTVRM ``` Address : #0129 Function : Put character on text screen Input : H - Y-position L - X-position Registers: AF ``` #### WRTVDP ``` Address : #012D Function : Write to VDP-register Input : B - Value to write C - Register number Registers: AF, BC ``` #### VDPSTA ``` Address : #0131 Function : Read VDP-status Input : A - Status register Output : A - Read value Registers: F ``` #### KYKLOK ``` Address : #0135 Function : Control KANA-key and KANA-lamp (Japan) Registers: AF ``` #### PUTCHR ``` Address : #0139 Function : Gets a key-code of keyboard, conversion to KANA and in buffer (Japan) Input : Z-flag set if not in conversion mode Registers: All ``` #### SETPAG ``` Address : #013D Function : Switches the page Input : ACPAGE - Active page DPPAGE - display page number Registers: AF ``` ### Palette-functions #### INIPLT ``` Address : #0141 Function : Initialises the palette (current palet is save in VRAM) Registers: AF, BC, DE ``` #### RSTPLT ``` Address : #0145 Function : Restores palette from VRAM Registers: AF, BC, DE ``` #### GETPLT ``` Address : #0149 Function : Obtains the colorcodes from the palette Input : A - Colorcode Output : B - RRRRBBBB C - xxxxGGGG Registers: AF, DE ``` #### SETPLT ``` Address : #014D Function : Sets the color code to the palette Input : D - Colorcode E - xxxxGGGG A - RRRRBBBB Registers: AF ``` #### PUTSPRT (Basic!) ``` Address : #0151 Function : Set sprites Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### COLOR (Basic!) ``` Address : #0155 Function : Changes Screen- or spritecolor, or palettevalues Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### SCREEN (Basic!) ``` Address : #0159 Function : Changes screenmode Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### WIDTHS (Basic!) ``` Address : #015D Function : Changes textscreen-width Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### VDP (Basic!) ``` Address : #0161 Function : Sets VDP-register Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### VDPF (Basic!) ``` Address : #0165 Function : Reads VDP-register Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### BASE (Basic!) ``` Address : #0169 Function : Sets VDP base-register Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### BASEF (Basic!) ``` Address : #016D Function : Reads VDP base-register Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### VPOKE (Basic!) ``` Address : #0171 Function : Writes a byte to VRAM Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### VPEEK (Basic!) ``` Address : #0175 Function : Reads a byte from VRAM Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### SETS (Basic!) ``` Address : #0179 Function : Sets BEEP, ADJUST, TIME and DATE Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### BEEP ``` Address : #017D Function : Generates beep Registers: All ``` #### PROMPT ``` Address : #0181 Function : Shows prompt (default: “Ok”) Registers: All ``` #### SDFSCR ``` Address : #0185 Function : Recovers screen-parameters of clock-chip. When C-flag is set function-key text will be displayd Input : C-flag reset after MSX-DOS call Registers: All ``` #### SETSCR ``` Address : #0189 Function : Recovers screen-parameter and prints Welcome message Registers: All ``` #### SCOPY (Basic!) ``` Address : #018D Function : Copy's VRAM, array and disk-file Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` ### BIT-BLIT routines From here on the so-called BIT-BLIT routines are listed, which are mostly executed by the VDP. The parameters must be passed through the system RAM at #F562. See the MSX 2 system variables documentation for more details. HL must always contain the value #F562 when calling. #### BLTVV ``` Address : #0191 Function : Copy VRAM to VRAM Input : SX, SY, DX, DY, NX, NY, ARG, L\_OP Registers: All ``` #### BLTVM ``` Address : #0195 Function : Copy Main-RAM to VRAM Input : SX - Address of screendata in RAM DX, DY, ARG, L\_OP. NX and NY must be in screendata Output : C-flag set if data failure in RAM Registers: All ``` #### BLTMV ``` Address : #0199 Function : Copy VRAM to Main-RAM Input : DX - Address of screendata in RAM SX, SY, ARG, L\_OP. NX and NY must be in screendata Registers: All ``` #### BLTVD ``` Address : #019D Function : Copy Diskfile to VRAM Input : SX -Address of filename. SX, SY, ARG, L\_OP. NX and NY must be in diskfile Registers: All ``` #### BLTDV ``` Address : #01A1 Function : Copy VRAM to Diskfile Input : DX - Address of filenaam. SX, SY, NX, NY,ARG Registers: All ``` #### BLTMD ``` Address : #01A5 Function : Copy Diskfile to Main-RAM Input : SX - Address of filenaam. DX - start-address DY - end-address (in Main-RAM) Registers: All ``` #### BLTDM ``` Address : #01A9 Function : Copy Main-RAM to Diskfile Input : DX - Address of filenaam. SX - start-address SY - end-address (in Main-RAM) Registers: All ``` #### NEWPAD ``` Address : #01AD Function : Read light pen, mouse and trackball Input : A - Function call number. Fetch device data first, then read. [ 8] Fetch light pen (#FF if available; touching screen) [ 9] Read X-position [10] Read Y-position [11] Read lightpen-status (#FF if pressed) [12] Fetch mouse/trackball in port 1 [13] Read X-offset [14] Read Y-offset [15] No function (always #00) [16] Fetch mouse/trackball in port 2 [17] Read X-offset [18] Read Y-offset [19] No function (always #00) [20] Fetch 2nd light pen (#FF if available; touching screen) [21] Read X-position [22] Read Y-position [23] Read light-pen status (#FF if pressed) Output : A - Read value Registers: All Remark : Access via [GTPAD](msxbios.php#GTPAD) in the main BIOS, function call numbers 8 and up will be forwarded to this call. ``` #### GETPUT (Basic!) ``` Address : #01B1 Function : GET TIME, GET DATE and PUT KANJI Input : HL - Basic textpointer Output : HL - Adapted Basic textpointer Registers: All ``` #### CHGMDP ``` Address : #01B5 Function : sets SCREEN-mode Input : A - SCREEN-mode Registers: All ``` #### RESVI ``` Address : #01B9 Function : Not used... Reserve entry ``` #### KNJPRT ``` Address : #01BD Function : Puts Kanji-character on graphical screen (5-8) Input : BC - JIS Kanji-character code A - Display-mode (0=full, 1=even, 2=odd) Registers: AF ``` #### REDCLK ``` Address : #01F5 Function : Read clock-RAM Input : C - clock-RAM address xxBBAAAA ||++++-- address ++------ Block-number Output : A - Read value in lowest four bits Registers: F ``` #### WRTCLK ``` Address : #01F9 Function : Write clock-RAM Input : C - clock-RAM address xxBBAAAA ||++++-- address : ++------ Block-number A - Value to write Registers: F ``` ~BiFi © 2025 MSX Assembly Page. MSX is a trademark of MSX Licensing Corporation.