nitrofurano Posted May 24, 2014 Share Posted May 24, 2014 hi everyone! since i have no idea how to use halt as waitvbl instruction (as i do on msx, sg1000, etc.), do someone know how to do it on colecovision? i guess it is related with interrupts? thanks! Quote Link to comment Share on other sites More sharing options...
+nanochess Posted May 24, 2014 Share Posted May 24, 2014 In Colecovision the VDP interrupt line is connected to the NMI pin of Z80, instead of INT as in SG-1000 The BIOS patches the $0066 location to jump to $8021, where you should put a JP to your routine. A simple interruption routine looks like this: PUSH AF PUSH HL IN A,($BF) ; Clear interruption POP HL POP AF RETN Now you can use HALT Quote Link to comment Share on other sites More sharing options...
nitrofurano Posted May 24, 2014 Author Share Posted May 24, 2014 thanks! it seems to take around 7 bytes, might fit fine on the cartridge header somehow! 1 Quote Link to comment Share on other sites More sharing options...
nitrofurano Posted May 24, 2014 Author Share Posted May 24, 2014 yes, it works perfectly! thanks! example01z1c4_nmihaltwaitvbl.zip 1 Quote Link to comment Share on other sites More sharing options...
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