DMAPT
Format: var = DMAPT (expr)
Supported by: RCA BASIC3 V1.1
Similar commands: Telmac SBASIC v 24.3: DMAPT
Load DMA PoinTer with value specified by expr, i.e. CPU 1802 register R0 (= DMA Register) will be loaded with the specified value.
Example
10 DMAPT (@D445)
Will result in R0 being loaded with the hexadecimal value of @D445.
Note that in the RCA BASIC3 V1.1 version (with BiosIo) that is included in the emulator the above command will NOT work. This is caused by some code introduced to handle output to a Pixie (CDP 1861) screen. This code will always reset R0 with @2000, which is used as the Pixie display buffer. If no Pixie output is used this feature can be turned off by changing address @21E7 and @21EA to #C4, from BASIC via:
POKE (@21E7,#C4) POKE (@21EA,#C4)
After these commands the DMAPT statement will work as intended.