そういえばSGDKを使ってMEGA DRIVEで、TMS9918を表示するプログラムを開発してました。
http://d.hatena.ne.jp/tanam/20140827/1409150993
Z80をTMS9995で書き直してみました。対比させながら書いてみたらZ80よりすっきり書けました！
*************************************************************** * This is a "Hello World" program for TMS9995 and TMS9918 VDP. * * Z80 version of Hello World was written by Timo "NYYRIKKI" Soilamaa * 17.10.2001 * * TMS9995 version of Hello World was written by TANAM * 17.01.2016 * *************************************************************** DATAP EQU >e000 * PYUTA VDP Data port CMDP EQU >e002 * PYUTA VDP Command port AORG >8000 *************************************************************** * cartridge header *************************************************************** data >5555 b @START CHARS * H 8006 byte >88,>88,>88,>F8,>88,>88,>88,>00 * e byte >00,>00,>70,>88,>F8,>80,>70,>00 * l byte >60,>20,>20,>20,>20,>20,>70,>00 * o byte >00,>00,>70,>88,>88,>88,>70,>00 * W byte >88,>88,>88,>A8,>A8,>D8,>88,>00 * r byte >00,>00,>B0,>C8,>80,>80,>80,>00 * d byte >08,>08,>68,>98,>88,>98,>68,>00 CHARS_END ORDER byte >1,>2,>3,>3,>4,>0,>5,>4,>6,>3,>7,>0 ORDER_END *************************************************************** * Program starts here: *************************************************************** START limi 0 * We don't know, how interrupts works in this system, so we disable them. lwpi >f030 * Set workspace to my area * Let's set VDP write address to #0000 * LD C,CMDP * XOR A * OUT (C),A li R0,>0040 movb R0,@CMDP * LD A,40H * OUT (C),A swpb R0 movb R0,@CMDP * Now let's clear first 16Kb of VDP memory * LD HL,3FFFH li R1,>3fff * LD C,DATAP * LD A,0 * OUT (C),A swpb R0 CLEAR movb R0,@DATAP * DEC HL * LD A,H * OR L NOP * Let's wait 8 clock cycles just in case VDP is not quick enough. NOP dec R1 * JR NZ,CLEAR joc CLEAR * Now it is time to set up VDP registers: *---------------------------------------- * Register 0 to #0 * * Set mode selection bit M3 (maybe also M4 & M5) to zero and * disable external video & horizontal interrupt * LD C,CMDP * OUT (C),A li R0,>0080 movb R0,@CMDP * LD A,80H * OUT (C),A swpb R0 movb R0,@CMDP *---------------------------------------- * Register 1 to #50 * * Select 40 column mode, enable screen and disable vertical interrupt * LD A,50H * OUT (C),A li R0,>5081 movb R0,@CMDP * LD A,81H * OUT (C),A swpb R0 movb R0,@CMDP *---------------------------------------- * Register 2 to #0 * * Set pattern name table to #0000 * XOR A * OUT (C),A li R0,>0082 movb R0,@CMDP * LD A,82H * OUT (C),A swpb R0 movb R0,@CMDP *---------------------------------------- * Register 3 is ignored as 40 column mode does not need color table * *---------------------------------------- * Register 4 to #1 * Set pattern generator table to #800 * LD A,1H * OUT (C),A li R0,>0184 movb R0,@CMDP * LD A,84H * OUT (C),A swpb R0 movb R0,@CMDP *---------------------------------------- * Registers 5 (Sprite attribute) & 6 (Sprite pattern) are ignored * as 40 column mode does not have sprites *---------------------------------------- * Register 7 to #F0 * Set colors to white on black * LD A,F0H * OUT (C),A li R0,>f087 movb R0,@CMDP * LD A,87H * OUT (C),A swpb R0 movb R0,@CMDP *---------------------------------------- * Let's set VDP write address to #808 so, that we can write * character set to memory * (No need to write SPACE it is clear char already) * LD A,8 * OUT (C),A li R0,>0848 movb R0,@CMDP * LD A,48H * OUT (C),A swpb R0 movb R0,@CMDP * Let's copy character set * LD HL,CHARS * LD B, CHARS_END-CHARS li R0,CHARS li R1,CHARS_END-CHARS * LD A,(HL) * LD C,DATAP * OUT (C),A COPYCHA movb *R0,@DATAP * INC HL inc R0 NOP * Let's wait 8 clock cycles just in case VDP is not quick enough. NOP * DJNZ COPYCHARS dec R1 joc COPYCHA * Let's set write address to start of name table * LD C,CMDP * XOR A * OUT (C),A li R0,>0040 movb R0,@CMDP * LD A,40H * OUT (C),A swpb R0 movb R0,@CMDP * Let's put characters to screen * LD HL,ORDER * LD B,ORDER_END-ORDER li R0,ORDER li R1,ORDER_END-ORDER * LD A,(HL) * LD C,DATAP * OUT (C),A COPYORD movb *R0,@DATAP * INC HL inc R0 NOP * Let's wait 8 clock cycles just in case VDP is not quick enough. NOP * DJNZ COPYORDER dec R1 joc COPYORD * >80f2 HALT b @HALT END
