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Switches to capture of the track 0 flag during a type 1 operation.

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This commit is contained in:
Thomas Harte 2019-12-24 21:43:20 -05:00
parent f633cf4c3f
commit 4205e95883
2 changed files with 17 additions and 5 deletions
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21
Components/1770/1770.cpp
View File

@ -63,10 +63,17 @@ uint8_t WD1770::get_register(int address) {
uint8_t status =
(status_.crc_error ? Flag::CRCError : 0) |
(status_.busy ? Flag::Busy : 0);
// Per Jean Louis-Guérin's documentation:
//
// * the write-protect bit is locked into place by a type 2 or type 3 command, but is
// read live after a type 1.
// * the track 0 bit is captured during a type 1 instruction and lost upon any other type,
// it is not live sampled.
switch(status_.type) {
case Status::One:
status |=
(get_drive().get_is_track_zero() ? Flag::TrackZero : 0) |
(status_.track_zero ? Flag::TrackZero : 0) |
(status_.seek_error ? Flag::SeekError : 0) |
(get_drive().get_is_read_only() ? Flag::WriteProtect : 0) |
(get_drive().get_index_pulse() ? Flag::Index : 0);
@ -219,6 +226,7 @@ void WD1770::posit_event(int new_event_type) {
update_status([] (Status &status) {
status.busy = true;
status.interrupt_request = false;
status.track_zero = false; // Always reset by a non-type 1; so reset regardless and set properly later.
});
LOG("Starting " << PADHEX(2) << int(command_));
@ -284,7 +292,7 @@ void WD1770::posit_event(int new_event_type) {
}
perform_seek_or_restore_command:
if(track_ == data_) goto verify;
if(track_ == data_) goto verify_seek;
step_direction_ = (data_ > track_);
adjust_track:
@ -293,7 +301,7 @@ void WD1770::posit_event(int new_event_type) {
perform_step:
if(!step_direction_ && get_drive().get_is_track_zero()) {
track_ = 0;
goto verify;
goto verify_seek;
}
get_drive().step(Storage::Disk::HeadPosition(step_direction_ ? 1 : -1));
Cycles::IntType time_to_wait;
@ -305,14 +313,17 @@ void WD1770::posit_event(int new_event_type) {
case 3: time_to_wait = (personality_ == P1772) ? 3 : 30; break;
}
WAIT_FOR_TIME(time_to_wait);
if(command_ >> 5) goto verify;
if(command_ >> 5) goto verify_seek;
goto perform_seek_or_restore_command;
perform_step_command:
if(command_ & 0x10) goto adjust_track;
goto perform_step;
verify:
verify_seek:
update_status([this] (Status &status) {
status.track_zero = get_drive().get_is_track_zero();
});
if(!(command_ & 0x04)) {
goto wait_for_command;
}

1
Components/1770/1770.hpp
View File

@ -96,6 +96,7 @@ class WD1770: public Storage::Disk::MFMController {
bool data_request = false;
bool interrupt_request = false;
bool busy = false;
bool track_zero = false;
enum {
One, Two, Three
} type = One;