Well recently I've been bored and looking for a new project to take on. Well something that's interested me is that I've seen it's possible to convert GG games to be played on a SMS. Well unfortunately I've only been able to come across one large section of information and that being the following site: http://www.disgruntleddesigner.com/chrisc/...ing/gg2sms.html On here he has many of the things that need to be changed, and well I got to thinking about a GG game that would be better on the big screen. First thing that came to my mind was Mega Man. One of the major complaints people have about Mega Man on the GG is the tiny screen not allowing you to see as much. Well if this game were on the SMS wouldn't it be able to have a larger view? Looking at the images on the site mentioned above it certainly seems that way. As for another problem is the fact that the SMS does not have a start button on the controller. The simplest thing I could think of would to be remap anything that uses the start button. The title screen and stage select could easily be changed to the 1 or 2 button and for the start menu I figured something like up+1 would be best since it would have the least interference. The only time you would have a problem is when shooting on ladders, but I figured down+1 would be a more problem because of holding your charged shot and then sliding. Basically what I'm wondering is are there any other limitations that I am not thinking of that will prevent this from working, besides the things I mentioned and the things on the site such has changing the palettes from 64 bytes to 32. Another item is has anyone here dabbled in this before that would maybe have some helpful hints to starting a project like this. From reading the tech diary on the site it seems the hard work is the finding where things are and just changing them for SMS compatibility.
I'm actually working on this. I started working on this a few months back, labeling things in a dissasembly slowly. I'm quite lazy so I haven't got much done, and I need to learn z80 better so I know what is going on some things I label. I need to find the pallete fading routine, figure out how the screen scrolling works, move the HUD, and change with the start button(Along with various other small things). For testing I've just been making the start button, button 1, which obviously doesn't work, because then you can't control. Here's the bit of the I/O ports I labeled(And probably got some parts wrong). Code (Text): IO_Port_Read:; Z80 I/O ports in a, ($00) cpl and $80 ld c, a in a, ($DC) ;Joypad port 1 (read only) cpl and $3F ;I/O port control or c ld hl, $C14C ld (hl), a inc l and (hl) inc l ld c, a and $0F ;not pressed ld b, a ld a, (hl) inc l and $F0 ;pressed or b ld b, a ld a, (hl) ButtonStart: ;Start button: part 1 bit 7, c jp nz, ButtonStart_2 and $7F res 7, b jp Button1 ButtonStart_2: ;Start button: part 2 bit 7, a jp nz, Button1 or $80 set 7, b Button1: ;Button 1: part 1 bit 4, c jp nz, Button1_2 and $EF res 4, b jp Button2 Button1_2: ;Button 1: part 2 bit 7, a jp nz, Button2 or $80 set 7, b Button2: ;Button 2: part 1 bit 5, c jp nz, Button2_2 and $DF res 5, b jp _LABEL_36D2_32 Button2_2: ;Button 2: part 2 bit 5, a jp nz, _LABEL_36D2_32 or $20 set 5, b
