I just heard this stuff is at least already emulated 
Huey: yes, I should add that, I got serveral emails from some russion guys also about it, The document needs updating, I got some more emails I need to process also, I will try to find the time to do that.
I reverse engineered this stuff myself back when writing the Z80 core for my own emulator (and ClosedMSX). The real name of the register is WZ, not MEMPTR.
Also, I'm pretty sure the "emulation" Manuel speaks of (in openMSX) is lacking.
GuyverR800: When I've updated the document would you be willing to review this WZ -section?
Also, I'm pretty sure the "emulation" Manuel speaks of (in openMSX) is lacking.
GuyveR800: I just checked the emulation of memptr/wz in openmsx and it matches the description of the memptr_eng.txt document perfectly. Can you be more specific in what exactly is lacking? Or is something missing in that document? Which version of openmsx did you check (very old versions indeed didn't emulate memptr). Thanks.
I'm not sure where this topic got hi-jacked... but a newbie doesn't really care about undocumented features yet (guyver I'm looking forward to a release of closedmsx)
For openMSX use this TCL script to see what is happening.
set throttle off
after time 4 {set throttle on}
ram_watch add 0xc80c -desc "Y Grid"
ram_watch add 0xc80d -desc "X Grid"
ram_watch add 0xc810 -desc "Char"
ram_watch add 0xc80f -desc "Stick"
ram_watch add 0xc810 -desc "Floor1"
ram_watch add 0xc811 -desc "Floor2"then compile this.
fname "Project1.rom" org $4000 dw "AB",init,0,0,0,0,0,0 call game init: ld a,31 ld (ram.ply_y),a ld (ram.ply_x),a ld a,0 ld (ram.ply_jstatus),a ld (ram.ply_pattern),a ld (ram.ply_jheight),a ld a,0xc ld (ram.ply_color),a ld a,60 ld (ram.ply_jmax),a ld a,1 ld (ram.ply_ws),a ld a,2 ld (ram.ply_jspeed),a call setscr call setcol call initspr call setspr call game ret game: ;ld b,0;the hell ;ld hl,teststr .loop: ld b,1 ;call wait call getGrid call setspr LD a,0 CALL 0xD5 ld (ram.ply_stick),a ld a,(ram.ply_stick) cp 1 call z,player_up ld a,(ram.ply_stick) cp 3 call z,player_right ld a,(ram.ply_stick) cp 5 call z,player_down ld a,(ram.ply_stick) cp 7 call z,player_left jp .loop ret wait: ;halt djnz wait RET player_up: ld a,(ram.ply_y) ld b,2 sub a,b ld (ram.ply_y),a ret player_down:ld a,(ram.ply_y) ld b,2 add a,b ld (ram.ply_y),a ret player_left:ld a,(ram.ply_x) ld b,2 sub a,b ld (ram.ply_x),a ret player_right:ld a,(ram.ply_x) ld b,2 add a,b ld (ram.ply_x),a ret getGrid:;translate y and x to an 8x8 grid ld a,(ram.ply_y) ; div Y by 8 srl a ; div by 2 srl a ; div by 2 srl a ; div by 2 add a,1 ; add 1 ld (ram.grid_y),a ld a,(ram.ply_x) ; div X by 8 srl a ; div by 2 srl a ; div by 2 srl a ; div by 2 ld (ram.grid_x),a ld a,(ram.grid_y) ; then do y*32+x ld l,a ld h,0 sla l rl h sla l rl h sla l rl h sla l rl h sla l rl h ld a,(ram.grid_x) ld c,a ld b,0 add hl,bc ld (ram.grid_y),hl ld a,(ram.grid_y) ld (ram.Grid_ScanY),a ld a,(ram.grid_x) ld (ram.Grid_ScanX),a ld hl,(ram.Grid_ScanY) ld bc,0x20 add hl,bc ld bc,0x1800 add hl,bc ;scan tile 1 call scangrid ld (ram.ply_floor1),a ;add 1 to the chan address ld bc,0x01 add hl,bc ;scan tile 2 call scangrid ld (ram.ply_floor2),a ret scangrid: ;add 0x1800 to get the right stuff ld (ram.Grid_ScanY),hl CALL 0x4a ld b,a ld a,98 call 0x4d halt ld a,b call 0x4d ;halt CALL 0x4a ld (ram.grid_chr),a ret ;------------------------------------------- ;init graphics and sprites ;------------------------------------------- setscr: ;CALL 0x41 ;SCREEN OFF LD a,0 ;disable keyclick LD (0xf3db),a CALL 0x72 ;switch to screen 2 LD HL,15+1024 ;color 15,1,1 LD (0xF3E9),HL XOR A LD (0xF3EB),A CALL 0x62 ;Set color LD A,1 ; let me type in screen2 LD (0xFCB0),A LD (0xFCAF),A LD A,32 ; 32 columns text mode LD (0XF3B0),A ;init screen2 for screen1 like use LD HL,0x00 ; VRAM start CALL SETVDP ; INIT VDP XOR A ; CLS CALL 0xC3 CALL 0x69 ; CLEAR sprS LD de,776+(0*2048) ; load fonts CALL initfnt LD de,776+(1*2048) CALL initfnt LD de,776+(2*2048) CALL initfnt CALL 0x44 ; SCREEN ON CALL 0x41 ;set screen off XOR a CALL 0xC3 ;CLS LD HL,FIELD0 ;Intro Screen CALL print CALL 0x44 ;set screen on ld hl,0x0a0a ld a,101 call 0x4d RET initfnt: LD bc,40 LD HL,font CALL $5c RET initcol: LD bc,40 LD HL,colors CALL $5c RET initspr: ld a,11100110b di out (0x99),a ld a,1+128 ei out (0x99),a LD de,0x3800 LD bc,32 LD HL,sprite CALL $5c ret setspr: ld de,0x1b00 ld bc,4 ld hl,ram.ply_y CALL $5c RET SETVDP: LD A,L DI OUT (0x99),A LD A,H AND 0x3f OR 0x40 OUT (0x99),A EI RET SETCOL: LD A,0xF0 ; set colors LD BC,2048 LD HL,0x2000 CALL 0x56 LD A,0xF0 LD BC,2048 LD HL,0x2800 CALL 0x56 LD A,0xF0 LD BC,2048 LD HL,0x3000 CALL 0x56 LD de,8192+776+(0*2048) ;load colors for fonts CALL initcol LD de,8192+776+(1*2048) CALL initcol LD de,8192+776+(2*2048) CALL initcol RET PRINT: LD A,(HL) INC HL AND A RET Z CALL 0xA2 JR PRINT RET ;01234567 Font: DB 00000000b DB 11111011b ;a DB 11111011b DB 11111011b DB 00000000b DB 11111111b DB 01111111b DB 01111111b DB 01010101b ;b DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 11111111b ;c DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 01010101b DB 11111111b ;d DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 11111111b DB 01010101b DB 01010101b ;e DB 10101010b DB 01010101b DB 10101010b DB 01010101b DB 10101010b DB 01010101b DB 10101010b colors: DB 0x00 DB 0x45 DB 0x57 DB 0x7e DB 0x00 DB 0x45 DB 0x57 DB 0x7e DB 0x54 DB 0x75 DB 0xe6 DB 0xfe DB 0xfe DB 0xfe DB 0xfe DB 0xfe DB 0xfe DB 0xfe DB 0xfe DB 0xfe DB 0xe7 DB 0x75 DB 0x54 DB 0x40 DB 0xfe DB 0xfe DB 0xfe DB 0xfe DB 0xe7 DB 0x75 DB 0x54 DB 0x40 DB 0x60 DB 0x80 DB 0x90 DB 0xa0 DB 0xb0 DB 0xe0 DB 0xf0 DB 0xf0 ;12345678 sprite: DB 10111101b DB 11011011b DB 01010111b DB 10101100b DB 11010011b DB 11101011b DB 01110011b DB 00001100b DB 00101101b DB 00101010b DB 00010110b DB 00101001b DB 01010110b DB 00001001b DB 00010111b DB 00011111b DB 11000000b DB 11110000b DB 10100010b DB 10110010b DB 01100011b DB 11100011b DB 00000011b DB 11011011b DB 11101011b DB 11100011b DB 01000011b DB 10100011b DB 00000010b DB 00000010b DB 00000000b DB 11000000b teststr: db "ac" db 0 FIELD0: ;01234567890123456789012345679012 DB "a a" DB "aa aa" DB "aa aa" DB "aa aa" DB "aa aaaaaaaaaaa aa" DB "aa aa" DB "aa aa" DB "aa aa" DB "aaaaaaaaaaa aaa aa" DB "aaaaaaaaaaa aaa aa" DB "aaaaaaaaaaa a aa" DB "aaaaaaaaaaa a aa" DB "aaaaaaaaaaaaa a aa" DB "aaaaaaaaaaaaa a aa" DB "aaaaaaaaaaa a aa" DB "aaaaaaaaaaa a aa" DB "aa aa a aa aa aaa" DB "aa a aa" DB "aa aaaaaaaaaaaa aa" DB "aa aa" DB "aa aa" DB "aa aa a aa" DB "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" DB 0 DS $6000-$ org $c800 ram: .ply_y: rb 1 ; x-pos .ply_x: rb 1 ; y-pos .ply_pattern: rb 1 ; player sprite pattern .ply_color: rb 1 ; player color .ply_ws: rb 1 ; Walk Speed .ply_direct: rb 1 ; direction .ply_jstatus: rb 1 ; Jump Stats (0=none 1=up 2=down) .ply_jheight: rb 1 ; Jump heigth .ply_jspeed: rb 1 ; Jump Speed .ply_jmax: rb 1 ; max jump height .grid_y: rb 1 ; y-grid pos .grid_x: rb 1 ; x-grid pos .Grid_ScanY: rb 1 ; x-scan .Grid_ScanX: rb 1 ; y-scan .ply_jump: rb 1 ; jump 1=yes 0=0 .ply_stick: rb 1 ; stick control .grid_chr: rb 1 ; grid CHR code .ply_floor1: rb 1 ; .ply_floor2: rb 1 ; .ply_fall: rb 1 ;
I would like to energize that long sensing feeling to learn to decently code the msx. And thus, this post.
Whooooww, what's this? Is this serious!?
You didn't tell me anything on this nostalgic feeling of you. Why the f*** do I need to find this out via the MRC?
When I first saw this BlueCrystal nick it triggered me immedialtely, that's the name S. used, is it him?, it is, whow fantastic (uh).
Any time for this revived hobby? Is your kitchen ready? I just finished painting the garage today :-)
Speak to you at Sinterklaas @ Maxet city.
Hey Pat,
Only been browsing things and looking at snippets of code that float the internet. I think that I grasp the basic concept, but doing it yourself is a whole different world 
I got some ideas I would like to try out.
The kitchen is close to completion, the plastering just needs more drying. You can continue your paint hobby at my place, if you like 
@d-Fader, hey how are you doing? I live in Stein (lb) nowadays. Married, children, the whole package. How is the looong awaited sequel to F1 spirit coming along?
Patai Gergely
Z80 Assembly - Index
sgate.emt.bme.hu/patai/publications/z80guide/index.html