Difference between revisions of "68k:Ports:600000"
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[[Category:68k:Ports:By Address|600000]] [[Category:68k:Ports:By Name|Battery Voltage]] | [[Category:68k:Ports:By Address|600000]] [[Category:68k:Ports:By Name|Battery Voltage]] | ||
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| + | This port controls I/O from pins 99 and 100 on the ASIC. It's used to check battery voltage on all calcs, and to control LCD contrast on the TI-92. | ||
{| | {| | ||
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| Bit 6 || Pin 99 output enable (keep =0) | | Bit 6 || Pin 99 output enable (keep =0) | ||
|- | |- | ||
| − | | Bit 5 || Data to pin 100 ( | + | | Bit 5 || Data to pin 100 (TI-92: used for LSB of LCD contrast) |
|- | |- | ||
| Bit 4 || Data to pin 99 (not used) | | Bit 4 || Data to pin 99 (not used) | ||
Revision as of 19:13, 4 June 2006
This port controls I/O from pins 99 and 100 on the ASIC. It's used to check battery voltage on all calcs, and to control LCD contrast on the TI-92.
| Bit 7 | Pin 100 output enable (keep =0) |
| Bit 6 | Pin 99 output enable (keep =0) |
| Bit 5 | Data to pin 100 (TI-92: used for LSB of LCD contrast) |
| Bit 4 | Data to pin 99 (not used) |
| Bit 3 | Data from pin 100 (not used) |
| Bit 2 | Data from pin 99 (1 if batt. voltage is above trigger level (see 600018) |
| Bits 1-0 | not used |
