Hi everyone! I am developing Cross Chase for the Creativision with CC65. The game has no sound, yet, but when run under Mame it produces a horrible buzzing sound. Could someone test it for me and let me know if this issue is real or just a Mame artifact? Which other emulator could I use to test my g...

I have figure it out! Problem solved!

I may have figured out how to write onto VDP registers and memory: #define VDP_DATA 0xC000 #define VDP_WRITE 0xC002 #include <peekpoke.h> void VDP_REGISTER(unsigned char reg, unsigned char value) { POKE(VDP_DATA,value); POKE(VDP_WRITE,(reg|0x80)); } void VDP_POKE(unsigned short address, unsigned cha...

I may have figured out how to write into VDP registers and video ram. I am assuming that the two data and status/write registers are at $C000, $C002. Is this the case for Creativision? I now need to understand where color and character definitions are located in video ram. On the MSX, color definiti...

[SOLVED!] Hi I would like to understand how to write into video memory in order to redefine characters and set their colors in mode 1. I have done this already on the MSX in C (by using Z88DK): https://github.com/Fabrizio-Caruso/CROSS-CHASE/blob/master/src/cross_lib/display/init_graphics/z88dk/msx/m...

@Mobsie @Carlsson I understand I need to write into VDP memory and registers. Are registers just part of VDP memory and are they addressed in the same (indirect) way by writing data into VDP_Status_Write? MSX Basic has something as simple as VPOKE and VPEEK which let us write and read into video ram...

Sorry guys, @carlsoon, I don't understand what the screen active bit is and how the VDP registers are accessed in your code LDA #$E2 ;new value including set screen active bit STA VDP_Status_Write LDA #$81 ;write into register 1 STA VDP_Status_Write ;see comments on that BIOS routine above Which is ...

Sorry I still do not understand why on other examples I see $80 added instead of $40. I need some simple to write into VDP memory from C without using interrupts. I am supposed to do this in C with very little Assembly. Let us assume the VDP registers are already set. I need: 1. a function VPOKE(loc...

Thanks Carlsson, My project is written in ANSI C with almost no Assembly for obvious reasons (it is a universal 8-bit game and framework for about 100 different 8-bit systems with any 8-bit CPU, i.e., Motorola 6809, Z80, 6502 and their clones/variants) Moreover I am not fluent in any Assembly. For t...

@carlsson, in a previous reply you said I should add #$40 and not #$80 to write.

I would have expected
LDA #$E2 ;new value including set screen active bit
STA VDP_Status_Write
LDA #$41 ;write into register 1
...
instead of
LDA #$81 ;write into register 1