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Centralised the 8272's actions of setting the non-DMA execution flag, picking the drive and head and loading the head for accessing commands, and switched error flag if read ID doesn't find anything.

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This commit is contained in:
Thomas Harte 2017-08-15 21:49:10 -04:00
parent d12c834f9c
commit aefbafa18d
2 changed files with 29 additions and 28 deletions
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56
Components/8272/i8272.cpp
View File

@ -293,23 +293,38 @@ void i8272::posit_event(int event_type) {
// If this is not clearly a command that's safe to carry out in parallel to a seek, end all seeks.
switch(command_[0] & 0x1f) {
case CommandSpecify:
case CommandSenseDriveStatus:
case CommandSenseInterruptStatus:
case CommandRecalibrate:
case CommandSeek:
case CommandReadData:
case CommandReadDeletedData:
case CommandWriteData:
case CommandWriteDeletedData:
case CommandReadTrack:
case CommandReadID:
case CommandFormatTrack:
case CommandScanLow:
case CommandScanLowOrEqual:
case CommandScanHighOrEqual:
is_access_command_ = true;
break;
default:
for(int c = 0; c < 4; c++) {
if(drives_[c].phase == Drive::Seeking) {
drives_[c].phase = Drive::NotSeeking;
drives_seeking_--;
}
}
is_access_command_ = false;
break;
}
if(is_access_command_) {
for(int c = 0; c < 4; c++) {
if(drives_[c].phase == Drive::Seeking) {
drives_[c].phase = Drive::NotSeeking;
drives_seeking_--;
}
}
// Establishes the drive and head being addressed, and whether in double density mode; populates the internal
// cylinder, head, sector and size registers from the command stream.
if(!dma_mode_) SetNonDMAExecution();
SET_DRIVE_HEAD_MFM();
LOAD_HEAD();
}
// Jump to the proper place.
switch(command_[0] & 0x1f) {
case CommandReadData:
@ -342,9 +357,6 @@ void i8272::posit_event(int event_type) {
// and searches for a sector that meets those criteria. If one is found, inspects the instruction in use and
// jumps to an appropriate handler.
read_write_find_header:
// Establishes the drive and head being addressed, and whether in double density mode; populates the internal
// cylinder, head, sector and size registers from the command stream.
LOAD_HEAD();
// Sets a maximum index hole limit of 2 then performs a find header/read header loop, continuing either until
// the index hole limit is breached or a sector is found with a cylinder, head, sector and size equal to the
@ -390,8 +402,6 @@ void i8272::posit_event(int event_type) {
// Performs the read data or read deleted data command.
read_data:
printf("Read [deleted] data [%02x %02x %02x %02x ... %02x %02x]\n", command_[2], command_[3], command_[4], command_[5], command_[6], command_[8]);
if(!dma_mode_) SetNonDMAExecution();
SET_DRIVE_HEAD_MFM();
read_next_data:
goto read_write_find_header;
@ -475,8 +485,6 @@ void i8272::posit_event(int event_type) {
write_data:
printf("Write [deleted] data [%02x %02x %02x %02x ... %02x %02x]\n", command_[2], command_[3], command_[4], command_[5], command_[6], command_[8]);
if(!dma_mode_) SetNonDMAExecution();
SET_DRIVE_HEAD_MFM();
if(drives_[active_drive_].drive->get_is_read_only()) {
SetNotWriteable();
@ -528,9 +536,7 @@ void i8272::posit_event(int event_type) {
// Performs the read ID command.
read_id:
// Establishes the drive and head being addressed, and whether in double density mode.
printf("Read ID\n");
SET_DRIVE_HEAD_MFM();
LOAD_HEAD();
printf("Read ID [%02x %02x]\n", command_[0], command_[1]);
// Sets a maximum index hole limit of 2 then waits either until it finds a header mark or sees too many index holes.
// If a header mark is found, reads in the following bytes that produce a header. Otherwise branches to data not found.
@ -538,7 +544,7 @@ void i8272::posit_event(int event_type) {
read_id_find_next_sector:
FIND_HEADER();
if(!index_hole_limit_) {
SetNoData();
SetMissingAddressMark();
goto abort;
}
READ_HEADER();
@ -554,8 +560,6 @@ void i8272::posit_event(int event_type) {
// Performs read track.
read_track:
printf("Read track [%02x %02x %02x %02x]\n", command_[2], command_[3], command_[4], command_[5]);
if(!dma_mode_) SetNonDMAExecution();
SET_DRIVE_HEAD_MFM();
// Wait for the index hole.
WAIT_FOR_EVENT(Event::IndexHole);
@ -597,15 +601,11 @@ void i8272::posit_event(int event_type) {
// Performs format [/write] track.
format_track:
printf("Format track\n");
if(!dma_mode_) SetNonDMAExecution();
SET_DRIVE_HEAD_MFM();
if(drives_[active_drive_].drive->get_is_read_only()) {
SetNotWriteable();
goto abort;
}
LOAD_HEAD();
// Wait for the index hole.
WAIT_FOR_EVENT(Event::IndexHole);
index_hole_count_ = 0;

1
Components/8272/i8272.hpp
View File

@ -66,6 +66,7 @@ class i8272: public Storage::Disk::MFMController {
void posit_event(int type);
int interesting_event_mask_;
int resume_point_;
bool is_access_command_;
// The counter used for ::Timer events.
int delay_time_;