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Factored out the standard [M]FM gap and mark groups, to increase 8272 readability and because it's pretty-much certain I'll need them again if ever I try to tackle e.g. the 8271.

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This commit is contained in:
Thomas Harte
2017-08-14 16:03:35 -04:00
parent 4df9307d25
commit a366298022
3 changed files with 82 additions and 56 deletions
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Components/8272/i8272.cpp
+5 -56
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@@ -427,31 +427,11 @@ void i8272::posit_event(int event_type) {
write_data_found_header:
begin_writing();
if(get_is_double_density()) {
write_n_bytes(50, 0x4e);
write_n_bytes(12, 0x00);
} else {
write_n_bytes(11, 0xff);
write_n_bytes(6, 0x00);
}
WAIT_FOR_EVENT(Event::DataWritten);
{
bool is_deleted = (command_[0] & 0x1f) == 0x09;
if(get_is_double_density()) {
get_crc_generator().set_value(Storage::Encodings::MFM::MFMPostSyncCRCValue);
for(int c = 0; c < 3; c++) write_raw_short(Storage::Encodings::MFM::MFMSync);
write_byte(is_deleted ? Storage::Encodings::MFM::DeletedDataAddressByte : Storage::Encodings::MFM::DataAddressByte);
} else {
get_crc_generator().reset();
get_crc_generator().add(is_deleted ? Storage::Encodings::MFM::DeletedDataAddressByte : Storage::Encodings::MFM::DataAddressByte);
write_raw_short(is_deleted ? Storage::Encodings::MFM::FMDeletedDataAddressMark : Storage::Encodings::MFM::FMDataAddressMark);
}
}
write_id_data_joiner((command_[0] & 0x1f) == 0x09);
SetDataDirectionFromProcessor();
SetDataRequest();
WAIT_FOR_EVENT(Event::DataWritten);
expects_input_ = true;
distance_into_section_ = 0;
@@ -563,32 +543,12 @@ void i8272::posit_event(int event_type) {
begin_writing();
// Write start-of-track.
if(get_is_double_density()) {
write_n_bytes(80, 0x4e);
write_n_bytes(12, 0x00);
for(int c = 0; c < 3; c++) write_raw_short(Storage::Encodings::MFM::MFMIndexSync);
write_byte(Storage::Encodings::MFM::IndexAddressByte);
write_n_bytes(50, 0x4e);
} else {
write_n_bytes(40, 0xff);
write_n_bytes(6, 0x00);
write_raw_short(Storage::Encodings::MFM::FMIndexAddressMark);
write_n_bytes(26, 0xff);
}
write_start_of_track();
WAIT_FOR_EVENT(Event::DataWritten);
sector_ = 0;
format_track_write_sector:
if(get_is_double_density()) {
write_n_bytes(12, 0x00);
for(int c = 0; c < 3; c++) write_raw_short(Storage::Encodings::MFM::MFMSync);
get_crc_generator().set_value(Storage::Encodings::MFM::MFMPostSyncCRCValue);
write_byte(Storage::Encodings::MFM::IDAddressByte);
} else {
write_n_bytes(6, 0x00);
get_crc_generator().reset();
write_raw_short(Storage::Encodings::MFM::FMIDAddressMark);
}
write_id_joiner();
// Write the sector header, obtaining its contents
// from the processor.
@@ -610,18 +570,7 @@ void i8272::posit_event(int event_type) {
write_crc();
// Write the sector body.
if(get_is_double_density()) {
write_n_bytes(22, 0x4e);
write_n_bytes(12, 0x00);
for(int c = 0; c < 3; c++) write_raw_short(Storage::Encodings::MFM::MFMSync);
get_crc_generator().set_value(Storage::Encodings::MFM::MFMPostSyncCRCValue);
write_byte(Storage::Encodings::MFM::DataAddressByte);
} else {
write_n_bytes(11, 0xff);
write_n_bytes(6, 0x00);
get_crc_generator().reset();
write_raw_short(Storage::Encodings::MFM::FMDataAddressMark);
}
write_id_data_joiner(false);
write_n_bytes(128 << command_[2], command_[5]);
write_crc();