Changes
/* Implementation details and use of Plus hardware */
* Plus sprites are used for man and enemies
* Plus split screen is used (for panel at the bottom)
* Plus pixel by pixel soft hardware scroll is used. (The left column is also masked by the border)
* Plus DMA is used (channel 0 is used for sound effects. Each sound effect is defined only by a list of DMA commands. e.g. no CPU driver is used to play them).
* bullets are done with soft sprites
* CRTC Register values are: R0 = 63, R1 = 40, R2 = 46, R3 = 14, R4 = 38, R5 = 0, R6 = 29, R7 = 32R0,R1,R2,R4,R5 are the normal values used by the system. R3 means a horizontal sync width of 14 chars, but a vertical sync width of 16 lines. R6 is 4 more lines than normal (probably for the panel at the bottom),R7 is 2 chars more than normal shifting the screen up by 2 char lines, to centralise the display and panel. The effect of the left column being masked is not compensated for.
== Links ==