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Diffstat (limited to 'src/devices/machine/cdp1871.c')
-rw-r--r-- | src/devices/machine/cdp1871.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/src/devices/machine/cdp1871.c b/src/devices/machine/cdp1871.c new file mode 100644 index 00000000000..e685f8c43ad --- /dev/null +++ b/src/devices/machine/cdp1871.c @@ -0,0 +1,290 @@ +// license:BSD-3-Clause +// copyright-holders:Curt Coder +/********************************************************************** + + RCA CDP1871 Keyboard Encoder emulation + +**********************************************************************/ + +#include "cdp1871.h" + + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +const device_type CDP1871 = &device_creator<cdp1871_device>; + + + +//************************************************************************** +// MACROS / CONSTANTS +//************************************************************************** + +const UINT8 cdp1871_device::key_codes[4][11][8] = +{ + // normal + { + { 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37 }, + { 0x38, 0x39, 0x3a, 0x3b, 0x2c, 0x2d, 0x2e, 0x2f }, + { 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67 }, + { 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f }, + { 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77 }, + { 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f }, + { 0x20, 0xff, 0x0a, 0x1b, 0xff, 0x0d, 0xff, 0x7f }, + { 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87 }, + { 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f }, + { 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97 }, + { 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f } + }, + + // alpha + { + { 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37 }, + { 0x38, 0x39, 0x3a, 0x3b, 0x2c, 0x2d, 0x2e, 0x2f }, + { 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 }, + { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f }, + { 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57 }, + { 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f }, + { 0x20, 0xff, 0x0a, 0x1b, 0xff, 0x0d, 0xff, 0x7f }, + { 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87 }, + { 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f }, + { 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97 }, + { 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f } + }, + + // shift + { + { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27 }, + { 0x28, 0x29, 0x2a, 0x2b, 0x3c, 0x3d, 0x3e, 0x3f }, + { 0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 }, + { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f }, + { 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57 }, + { 0x58, 0x59, 0x5a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f }, + { 0x20, 0xff, 0x0a, 0x1b, 0xff, 0x0d, 0xff, 0x7f }, + { 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87 }, + { 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f }, + { 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97 }, + { 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f } + }, + + // control + { + { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }, + { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }, + { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 }, + { 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f }, + { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 }, + { 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f }, + { 0x20, 0xff, 0x0a, 0x1b, 0xff, 0x0d, 0xff, 0x7f }, + { 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87 }, + { 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f }, + { 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97 }, + { 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f } + } +}; + + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// cdp1871_device - constructor +//------------------------------------------------- + +cdp1871_device::cdp1871_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, CDP1871, "RCA CDP1871", tag, owner, clock, "cdp1871", __FILE__), + m_read_d1(*this), + m_read_d2(*this), + m_read_d3(*this), + m_read_d4(*this), + m_read_d5(*this), + m_read_d6(*this), + m_read_d7(*this), + m_read_d8(*this), + m_read_d9(*this), + m_read_d10(*this), + m_read_d11(*this), + m_write_da(*this), + m_write_rpt(*this), + m_inhibit(false), + m_sense(0), + m_drive(0), + m_shift(0), + m_shift_latch(0), + m_control(0), + m_control_latch(0), + m_alpha(0), + m_da(0), + m_next_da(CLEAR_LINE), + m_rpt(0), + m_next_rpt(CLEAR_LINE) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void cdp1871_device::device_start() +{ + // resolve callbacks + m_read_d1.resolve_safe(0xff); + m_read_d2.resolve_safe(0xff); + m_read_d3.resolve_safe(0xff); + m_read_d4.resolve_safe(0xff); + m_read_d5.resolve_safe(0xff); + m_read_d6.resolve_safe(0xff); + m_read_d7.resolve_safe(0xff); + m_read_d8.resolve_safe(0xff); + m_read_d9.resolve_safe(0xff); + m_read_d10.resolve_safe(0xff); + m_read_d11.resolve_safe(0xff); + m_write_da.resolve_safe(); + m_write_rpt.resolve_safe(); + + // set initial values + change_output_lines(); + + // allocate timers + m_scan_timer = timer_alloc(); + m_scan_timer->adjust(attotime::zero, 0, attotime::from_hz(clock())); + + // register for state saving + save_item(NAME(m_inhibit)); + save_item(NAME(m_sense)); + save_item(NAME(m_drive)); + save_item(NAME(m_shift)); + save_item(NAME(m_shift_latch)); + save_item(NAME(m_control)); + save_item(NAME(m_control_latch)); + save_item(NAME(m_alpha)); + save_item(NAME(m_da)); + save_item(NAME(m_next_da)); + save_item(NAME(m_rpt)); + save_item(NAME(m_next_rpt)); +} + + +//------------------------------------------------- +// device_timer - handler timer events +//------------------------------------------------- + +void cdp1871_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) +{ + change_output_lines(); + clock_scan_counters(); + detect_keypress(); +} + + +//------------------------------------------------- +// change_output_lines - change output lines +//------------------------------------------------- + +void cdp1871_device::change_output_lines() +{ + if (m_next_da != m_da) + { + m_da = m_next_da; + + m_write_da(m_da); + } + + if (m_next_rpt != m_rpt) + { + m_rpt = m_next_rpt; + + m_write_rpt(m_rpt); + } +} + + +//------------------------------------------------- +// clock_scan_counters - clock the keyboard +// scan counters +//------------------------------------------------- + +void cdp1871_device::clock_scan_counters() +{ + if (!m_inhibit) + { + m_sense++; + + if (m_sense == 8) + { + m_sense = 0; + m_drive++; + + if (m_drive == 11) + { + m_drive = 0; + } + } + } +} + + +//------------------------------------------------- +// detect_keypress - detect key press +//------------------------------------------------- + +void cdp1871_device::detect_keypress() +{ + UINT8 data = 0; + + switch (m_drive) { + case 0: data = m_read_d1(0); break; + case 1: data = m_read_d2(0); break; + case 2: data = m_read_d3(0); break; + case 3: data = m_read_d4(0); break; + case 4: data = m_read_d5(0); break; + case 5: data = m_read_d6(0); break; + case 6: data = m_read_d7(0); break; + case 7: data = m_read_d8(0); break; + case 8: data = m_read_d9(0); break; + case 9: data = m_read_d10(0); break; + case 10: data = m_read_d11(0); break; + } + + if (data == (1 << m_sense)) + { + if (!m_inhibit) + { + m_shift_latch = m_shift; + m_control_latch = m_control; + m_inhibit = true; + m_next_da = ASSERT_LINE; + } + else + { + m_next_rpt = ASSERT_LINE; + } + } + else + { + m_inhibit = false; + m_next_rpt = CLEAR_LINE; + } +} + + +//------------------------------------------------- +// read - keyboard data read +//------------------------------------------------- + +READ8_MEMBER( cdp1871_device::read ) +{ + int table = 0; + + if (m_control_latch) table = 3; else if (m_shift_latch) table = 2; else if (m_alpha) table = 1; + + // reset DA on next TPB + m_next_da = CLEAR_LINE; + + return key_codes[table][m_drive][m_sense]; +} |