Mercurial > repos > blastem
diff blastem.c @ 345:29d2ca563499
Don't sync the 68K clock to the VDP clock unless the 68K had to wait for the VDP. This unfortunately breaks the direct color DMA demos, but should be more correct overall.
author | Mike Pavone <pavone@retrodev.com> |
---|---|
date | Sun, 19 May 2013 13:47:47 -0700 |
parents | b46771135442 |
children | aff29d50afd5 |
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--- a/blastem.c Sun May 19 11:38:15 2013 -0700 +++ b/blastem.c Sun May 19 13:47:47 2013 -0700 @@ -253,8 +253,8 @@ vdp_context * v_context = context->video_context; if (vdp_port < 0x10) { int blocked; + uint32_t before_cycle = v_context->cycles; if (vdp_port < 4) { - uint32_t before_cycle = v_context->cycles; while (vdp_data_port_write(v_context, value) < 0) { while(v_context->flags & FLAG_DMA_RUN) { vdp_run_dma_done(v_context, mclks_per_frame); @@ -314,7 +314,9 @@ printf("Illegal write to HV Counter port %X\n", vdp_port); exit(1); } - context->current_cycle = v_context->cycles/MCLKS_PER_68K; + if (v_context->cycles != before_cycle) { + context->current_cycle = v_context->cycles / MCLKS_PER_68K; + } } else if (vdp_port < 0x18) { //TODO: Implement PSG } else {