2019-07-28 22:16:51 +00:00
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;ACME 0.96.4
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2012-11-26 23:11:45 +00:00
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!ifdef lib_cbm_c64_cia1_a !eof
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lib_cbm_c64_cia1_a = 1
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2019-07-28 22:16:51 +00:00
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!source <cbm/cia.a> ; chip stuff (same for both cias)
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; stuff for cia 1 only:
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!addr cia1_base = $dc00
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2021-08-11 16:55:40 +00:00
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; both port A and port B are connected to the keyboard matrix.
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; in addition to that, they are used for:
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cia1_pra = cia1_base + cia_port_a
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; %7....... writing 0 selects paddles at port 1
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; %.6...... writing 0 selects paddles at port 2
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; %...4.... reading 0 means JOY2_BUTTON
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; %....3... reading 0 means JOY2_RIGHT
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; %.....2.. reading 0 means JOY2_LEFT
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; %......1. reading 0 means JOY2_DOWN
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; %.......0 reading 0 means JOY2_UP
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; kernal's keyboard scanner writes values where a single bit is cleared, going from lsb to msb.
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; so most of the time, the last value written will be $7f.
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cia1_prb = cia1_base + cia_port_b
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; %...4.... reading 0 means JOY1_BUTTON
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; %....3... reading 0 means JOY1_RIGHT
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; %.....2.. reading 0 means JOY1_LEFT
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; %......1. reading 0 means JOY1_DOWN
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; %.......0 reading 0 means JOY1_UP
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cia1_ddra = cia1_base + cia_data_direction_a ; kernal writes $ff to set to output for keyboard scanner
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cia1_ddrb = cia1_base + cia_data_direction_b ; kernal writes $00 to set to input for keyboard scanner
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2019-07-28 22:16:51 +00:00
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cia1_ta_lo = cia1_base + cia_timer_a_low
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cia1_ta_hi = cia1_base + cia_timer_a_high
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cia1_tb_lo = cia1_base + cia_timer_b_low
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cia1_tb_hi = cia1_base + cia_timer_b_high
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cia1_tod10ths = cia1_base + cia_timeofday_10ths
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cia1_todsec = cia1_base + cia_timeofday_seconds
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cia1_todmin = cia1_base + cia_timeofday_minutes
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cia1_todhr = cia1_base + cia_timeofday_hours
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cia1_sdr = cia1_base + cia_serial_data
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cia1_icr = cia1_base + cia_interrupt_control
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cia1_cra = cia1_base + cia_control_a
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cia1_crb = cia1_base + cia_control_b
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; the interrupt output is connected to CPU's /IRQ input
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; in the C128, the shift register is used for the fast serial port (burst mode)
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