Maintenance script: Initial automated import

2016-02-06T07:13:38Z

Initial automated import

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= Basic Info =

'''Port Address: 02'''

This port reports various status information, including battery strength, LCD driver status, and calculator type.

= Writing to Port =

'''TI-83+ (Non-SE)'''
No effect.

'''TI-83+SE, TI-84+, TI-84+SE, TI-84+CSE'''
Bit 0: Write a 0 to acknowledge the ON key interrupt; write 1 to leave the status of the ON key interrupt alone.
Bit 1: ACK HW timer 1
Bit 2: ACK HW timer 2
Bit 3: Ignored
Bit 4: ACK Linkport
Bits 5-7: Ignored

= Reading from Port =
Bit 0: Set if the batteries are good. Reset if the batteries are low. The calculator will refuse to Garbage Collect or receive a FLASH App or OS when the batteries are low. The voltage cutoff can be configured in port 04.
'''83+SE / 84+(SE) only:''' Bit 1: At 15MHz this bit resets for a set delay after a command or data is sent to the LCD, otherwise this bit is always set. The amount of delay is controlled by port 2F. On the TI-73, this bit is always reset (this is how you distinguish between the 73 and 83+ series hardware).
Bit 2: Set if Flash is currently unlocked.
'''83+ only:''' Bits 3-5:
Bit 3: Last value written to port 05 bit 0
Bit 4: Last value written to port 05 bit 1
Bit 5: Last value written to port 05 bit 2
'''84+(SE) only:''' Bit 5: Set for TI-84+ and TI-84+ SE calculators. Reset for TI-83+ and TI-83+ SE calculators. More specifically, this indicates if the calculator is USB-capable or not.
Bit 6: Indicates if Link Assist is available.
Bit 7: Reset for a TI-83+ Basic. Set for everything else.

= Example Uses =

'''Battery checking'''

push af
in a, (2)
and 01h
call nz, BatteriesGood
call z, BatteriesLow
pop af

'''LCD Testing'''

push af
WaitLoop:
in a, (2)
and 02h
jr z, WaitLoop
;Send a command, like 03 (LCD "On").
call LCDIsReady
pop af

'''Device checking'''
This example also uses Port 21h.

in a, (2)
rlca ;Roll bit 7 into carry.
jp nc, Regular83Plus
and 40h ;Test bit 5, now rotated into bit 6.
jp z, Silver83Plus
in a, (21h)
and 03h
jp z, Regular84Plus
jp nz, Silver84Plus

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[[Category:Z80 Assembly]]
[[Category:Z80 Heaven]]
[[Category:Z80 Ports]]

Z80:Ports:Port02 - Revision history

Maintenance script: Initial automated import