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author | 2014-04-22 12:21:07 +0000 | |
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committer | 2014-04-22 12:21:07 +0000 | |
commit | c046734f76db73405b7f58663f5b44be327d33db (patch) | |
tree | 66fecdc57ac03045532d6380b1c09f4ed38b14ec /src/emu/cpu/alto2/a2dwt.c | |
parent | 92d6b69712905fc7623301da72deb46613092018 (diff) |
(MESS) New driver added: Xerox Alto 2 [Juergen Buchmueller]
out of whatsnew: Did not add Unicode support for debugger from branch yet, for now few special chars are converted to be plain ASCII
Diffstat (limited to 'src/emu/cpu/alto2/a2dwt.c')
-rw-r--r-- | src/emu/cpu/alto2/a2dwt.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/emu/cpu/alto2/a2dwt.c b/src/emu/cpu/alto2/a2dwt.c new file mode 100644 index 00000000000..07c5f07ae65 --- /dev/null +++ b/src/emu/cpu/alto2/a2dwt.c @@ -0,0 +1,64 @@ +/***************************************************************************** + * + * Xerox AltoII display word task + * + * Copyright Juergen Buchmueller <pullmoll@t-online.de> + * + * Licenses: MAME, GPLv2 + * + *****************************************************************************/ +#include "alto2cpu.h" + +//! PROM a38 bit O1 is STOPWAKE' (stop DWT if bit is zero) +#define FIFO_STOPWAKE(a38) (0 == (a38 & disp_a38_STOPWAKE) ? true : false) + +/** + * @brief block the display word task + */ +void alto2_cpu_device::f1_early_dwt_block() +{ + m_dsp.dwt_blocks = true; + + /* clear the wakeup for the display word task */ + m_task_wakeup &= ~(1 << m_task); + LOG((LOG_DWT,2," BLOCK %s\n", task_name(m_task))); + + /* wakeup the display horizontal task, if it didn't block itself */ + if (!m_dsp.dht_blocks) + m_task_wakeup |= 1 << task_dht; +} + +/** + * @brief load the display data register + */ +void alto2_cpu_device::f2_late_dwt_load_ddr() +{ + LOG((LOG_DWT,2," DDR<- BUS (%#o)\n", m_bus)); + m_dsp.fifo[m_dsp.wa] = m_bus; + m_dsp.wa = (m_dsp.wa + 1) % ALTO2_DISPLAY_FIFO; + UINT8 a38 = m_disp_a38[m_dsp.ra * 16 + m_dsp.wa]; + if (FIFO_STOPWAKE(a38)) + m_task_wakeup &= ~(1 << task_dwt); + LOG((LOG_DWT,2, " DWT push %04x into FIFO[%02o]%s\n", + m_bus, (m_dsp.wa - 1) & (ALTO2_DISPLAY_FIFO - 1), + FIFO_STOPWAKE(a38) ? " STOPWAKE" : "")); +} + +void alto2_cpu_device::init_dwt(int task) +{ + set_f1(task, f1_block, &alto2_cpu_device::f1_early_dwt_block, 0); + set_f2(task, f2_dwt_load_ddr, 0, &alto2_cpu_device::f2_late_dwt_load_ddr); +} + +void alto2_cpu_device::exit_dwt() +{ + // nothing to do yet +} + +void alto2_cpu_device::reset_dwt() +{ + m_dsp.dwt_blocks = false; + memset(m_dsp.fifo, 0, sizeof(m_dsp.fifo)); + m_dsp.wa = 0; + m_dsp.ra = 0; +} |