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// license:BSD-3-Clause
// copyright-holders:Juergen Buchmueller
/*****************************************************************************
*
* Xerox AltoII disk controller block
*
*****************************************************************************/
#ifdef ALTO2_DEFINE_CONSTANTS
#else // ALTO2_DEFINE_CONSTANTS
#ifndef MAME_CPU_ALTO2_A2DISK_H
#define MAME_CPU_ALTO2_A2DISK_H
required_device_array<diablo_hd_device, 2> m_drive; //!< two diablo_hd_device drives
//! disk controller context
struct {
uint8_t drive; //!< selected drive from KADDR[14] (written to data out with SENDADR)
uint16_t kaddr; //!< A[0-15] disk hardware address (sector, cylinder, head, drive, restore)
uint16_t kadr; //!< C[0-15] with read/write/check modes for header, label and data
uint16_t kstat; //!< S[0-15] disk status
uint16_t kcom; //!< disk command (5 bits kcom[1-5])
uint8_t krecno; //!< record number (2 bits indexing header, label, data, -/-)
uint8_t egate; //!< current erase gate signal to the DIABLO hd
uint8_t wrgate; //!< current write gate signal to the DIABLO hd
uint8_t rdgate; //!< current read gate signal to the DIABLO hd
uint32_t shiftin; //!< input shift register
uint32_t shiftout; //!< output shift register
uint32_t datain; //!< disk data in latch
uint32_t dataout; //!< disk data out latch
uint8_t krwc; //!< read/write/check for current record
uint8_t kfer; //!< disk fatal error signal state
uint8_t wdtskena; //!< disk word task enable (active low)
uint8_t wddone; //!< previous state of WDDONE
uint8_t wdinit0; //!< disk word task init at the early microcycle
uint8_t wdinit; //!< disk word task init at the late microcycle
uint8_t strobe; //!< strobe (still) active
emu_timer* strobon_timer; //!< set strobe on timer
uint8_t bitclk; //!< current bitclk state (either crystal clock, or rdclk from the drive)
attoseconds_t bitclk_time[2]; //!< per drive time in attoseconds per bit
uint8_t datin; //!< current datin from the drive
uint8_t bitcount; //!< bit counter
uint8_t carry; //!< carry output of the bitcounter
uint8_t seclate; //!< sector late (monoflop output)
emu_timer* seclate_timer; //!< sector late timer
uint8_t seekok; //!< seekok state (SKINC' & LAI' & ff_44a.Q')
uint8_t ok_to_run; //!< ok to run signal (set to 1 some time after reset)
emu_timer* ok_to_run_timer; //!< ok to run timer
uint8_t ready_mf31a; //!< ready monoflop 31a
emu_timer* ready_timer; //!< ready timer
uint8_t seclate_mf31b; //!< seclate monoflop 31b
jkff_t ff_21a; //!< JK flip-flop 21a (sector task)
jkff_t ff_21a_old; //!< -"- previous state
jkff_t ff_21b; //!< JK flip-flop 21b (sector task)
jkff_t ff_22a; //!< JK flip-flop 22a (sector task)
jkff_t ff_22b; //!< JK flip-flop 22b (sector task)
jkff_t ff_43b; //!< JK flip-flop 43b (word task)
jkff_t ff_53a; //!< JK flip-flop 53a (word task)
jkff_t ff_43a; //!< JK flip-flop 43a (word task)
jkff_t ff_53b; //!< brief JK flip-flop 53b (word task)
jkff_t ff_44a; //!< JK flip-flop 44a (LAI' clocked)
jkff_t ff_44b; //!< JK flip-flop 44b (CKSUM)
jkff_t ff_45a; //!< JK flip-flop 45a (ready latch)
jkff_t ff_45b; //!< JK flip-flop 45b (seqerr latch)
} m_dsk;
jkff_t m_sysclka0[4]; //!< simulate previous sysclka
jkff_t m_sysclka1[4]; //!< simulate current sysclka
jkff_t m_sysclkb0[4]; //!< simulate previous sysclkb
jkff_t m_sysclkb1[4]; //!< simulate current sysclkb
void kwd_timing(int bitclk, int datin, int block); //!< disk word timing
TIMER_CALLBACK_MEMBER( disk_seclate ); //!< timer callback to take away the SECLATE pulse (monoflop)
TIMER_CALLBACK_MEMBER( disk_ok_to_run ); //!< timer callback to take away the OK TO RUN pulse (reset)
TIMER_CALLBACK_MEMBER( disk_strobon ); //!< timer callback to pulse the STROBE' signal to the drive
TIMER_CALLBACK_MEMBER( disk_ready_mf31a ); //!< timer callback to change the READY monoflop 31a
void disk_bitclk(int arg); //!< function to update the disk controller with a new bitclk
void disk_block(int task); //!< called if one of the disk tasks (task_kwd or task_ksec) blocks
void bs_early_read_kstat(); //!< bus source: bus driven by disk status register KSTAT
void bs_early_read_kdata(); //!< bus source: bus driven by disk data register KDATA input
void f1_late_strobe(); //!< F1 func: initiates a disk seek
void f1_late_load_kstat(); //!< F1 func: load disk status register
void f1_late_load_kdata(); //!< F1 func: load data out register, or the disk address register
void f1_late_increcno(); //!< F1 func: advances shift registers holding KADR
void f1_late_clrstat(); //!< F1 func: reset all error latches
void f1_late_load_kcom(); //!< F1 func: load the KCOM register from bus
void f1_late_load_kadr(); //!< F1 func: load the KADR register from bus
void f2_late_init(); //!< F2 func: branch on disk word task active and init
void f2_late_rwc(); //!< F2 func: branch on read/write/check state of the current record
void f2_late_recno(); //!< F2 func: branch on the current record number by a lookup table
void f2_late_xfrdat(); //!< F2 func: branch on the data transfer state
void f2_late_swrnrdy(); //!< F2 func: branch on the disk ready signal
void f2_late_nfer(); //!< f2_nfer late: branch on the disk fatal error condition
void f2_late_strobon(); //!< f2_strobon late: branch on the seek busy status
void init_disk(); //!< initialize the disk controller
void exit_disk(); //!< deinitialize the disk controller
void reset_disk(); //!< reset the disk controller
#endif // MAME_CPU_ALTO2_A2DISK_H
#endif // ALTO2_DEFINE_CONSTANTS
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