Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision | ||
|
screen_map [2016/05/29 22:03] ex_writer |
— (current) | ||
|---|---|---|---|
| Line 1: | Line 1: | ||
| - | ====== Screen Map ====== | ||
| - | |||
| - | In the Bally Professional Arcade, two bits of RAM define each screen pixel. Therefore, one 8-bit byte of RAM defines four pixels on the screen. | ||
| - | |||
| - | In low-resolution mode, 40 bytes define a line of screen data, providing a horizontal resolution of 160 pixels. The vertical resolution is 102 lines. The areas of the screen defined by the display RAM therefore requires 102 x 40 = 4,080 bytes. The remaining 16 bytes of screen RAM are used for [[scratchpad]]. More RAM can be reserved for [[scratchpad]] by [[blanking]] the screen before the 102nd line. | ||
| - | |||
| - | [High-resolution explanation omitted.] | ||
| - | |||
| - | The first byte of RAM is in the upper lefthand corner of the screen. As RAM addresses increases, the screen position moves in the same direction as the TV scan: from left to right and from top to bottom. The four pixels in each byte are displayed with the least significant pixel (bits 0 and 1) on the right. | ||
| - | |||
| - | {{screen_map.png}} | ||
| - | |||
| - | [NM:85–6] | ||
