Register - Bitmap Data
From NerdConsole
Jump to navigationJump to search
To load data into the bitmap graphics buffers you must stream it into place 1 byte at a time. Without this approach it's not possible to address 192K bytes of data with a 16-bit address bus on the 65C02 CPU. First, set the address where data will be placed, then set the data that goes in that spot.
Address
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|---|
| $02E8 | A | A | A | A | A | A | A | A |
| $02E9 | A | A | A | A | A | A | A | A |
| $02EA | - | - | - | - | - | - | A | A |
Key
- A - Address in the bitmap buffer where data will be written.
Data
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|---|
| $02EF | D | D | D | D | D | D | D | D |
Key
- D - Data to set in the bitmap buffer.
This register is a part of the Control Page.
