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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{|
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| Bit 6 || Pin 99 output enable (keep =0)
 
| Bit 6 || Pin 99 output enable (keep =0)
 
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|-
| Bit 5 || Data to pin 100 (not used)
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| Bit 5 || Data to pin 100 (TI-92: used for LSB of LCD contrast)
 
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|-
 
| Bit 4 || Data to pin 99 (not used)
 
| Bit 4 || Data to pin 99 (not used)

Revision as of 20:13, 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