From 0e0c789b0261c9561a2291541bd58491a5dafd4a Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 17 Aug 2019 23:43:42 -0400
Subject: [PATCH] Starts attempting to introduce a direct access device.
Without having access to the SCSI-1 standard, a lot of this is guesswork.
---
Components/5380/DirectAccessDevice.cpp | 57 +++++++++++++++++++
Components/5380/DirectAccessDevice.hpp | 44 ++++++++++++++
Components/5380/SCSI.cpp | 22 ++++---
Components/5380/SCSI.hpp | 10 +++-
Components/5380/ncr5380.cpp | 40 ++++++++-----
Components/5380/ncr5380.hpp | 7 ++-
.../Clock Signal.xcodeproj/project.pbxproj | 6 ++
7 files changed, 164 insertions(+), 22 deletions(-)
create mode 100644 Components/5380/DirectAccessDevice.cpp
create mode 100644 Components/5380/DirectAccessDevice.hpp
diff --git a/Components/5380/DirectAccessDevice.cpp b/Components/5380/DirectAccessDevice.cpp
new file mode 100644
index 000000000..6d776836e
--- /dev/null
+++ b/Components/5380/DirectAccessDevice.cpp
@@ -0,0 +1,57 @@
+//
+// DirectAccessDevice.cpp
+// Clock Signal
+//
+// Created by Thomas Harte on 17/08/2019.
+// Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#include "DirectAccessDevice.hpp"
+
+using namespace SCSI;
+
+DirectAccessDevice::DirectAccessDevice(Bus &bus, int scsi_id) :
+ bus_(bus),
+ scsi_id_mask_(BusState(1 << scsi_id)),
+ scsi_bus_device_id_(bus.add_device()) {
+ bus.add_observer(this);
+}
+
+void DirectAccessDevice::scsi_bus_did_change(Bus *, BusState new_state) {
+ /*
+ "The target determines that it is selected when the SEL# signal
+ and its SCSI ID bit are active and the BSY# and I#/O signals
+ are false. It then asserts the signal within a selection abort
+ time."
+ */
+
+ switch(state_) {
+ case State::Inactive:
+ if(
+ (new_state & scsi_id_mask_) &&
+ ((new_state & (Line::SelectTarget | Line::Busy | Line::Input)) == Line::SelectTarget)
+ ) {
+ state_ = State::Selected;
+ bus_state_ |= Line::Busy | Line::Request;
+ bus_.set_device_output(scsi_bus_device_id_, bus_state_);
+ }
+ break;
+
+ case State::Selected:
+ switch(new_state & (Line::Request | Line::Acknowledge)) {
+ case Line::Request | Line::Acknowledge:
+ bus_state_ &= ~Line::Request;
+ printf("Got %02x maybe?\n", bus_state_ & 0xff);
+ break;
+
+ case Line::Acknowledge:
+ case 0:
+ bus_state_ |= Line::Request;
+ break;
+
+ default: break;
+ }
+ bus_.set_device_output(scsi_bus_device_id_, bus_state_);
+ break;
+ }
+}
diff --git a/Components/5380/DirectAccessDevice.hpp b/Components/5380/DirectAccessDevice.hpp
new file mode 100644
index 000000000..e92d486ce
--- /dev/null
+++ b/Components/5380/DirectAccessDevice.hpp
@@ -0,0 +1,44 @@
+//
+// DirectAccessDevice.hpp
+// Clock Signal
+//
+// Created by Thomas Harte on 17/08/2019.
+// Copyright © 2019 Thomas Harte. All rights reserved.
+//
+
+#ifndef DirectAccessDevice_hpp
+#define DirectAccessDevice_hpp
+
+#include "SCSI.hpp"
+
+namespace SCSI {
+
+/*!
+ Models a SCSI direct access device, ordinarily some sort of
+ hard drive.
+*/
+class DirectAccessDevice: public Bus::Observer {
+ public:
+ /*!
+ Instantiates a direct access device attached to @c bus,
+ with SCSI ID @c scsi_id — a number in the range 0 to 7.
+ */
+ DirectAccessDevice(Bus &bus, int scsi_id);
+
+ private:
+ void scsi_bus_did_change(Bus *, BusState new_state) final;
+
+ Bus &bus_;
+ const BusState scsi_id_mask_;
+ const size_t scsi_bus_device_id_;
+
+ enum class State {
+ Inactive,
+ Selected
+ } state_ = State::Inactive;
+ BusState bus_state_ = DefaultBusState;
+};
+
+}
+
+#endif /* DirectAccessDevice_hpp */
diff --git a/Components/5380/SCSI.cpp b/Components/5380/SCSI.cpp
index 1ae837b05..a6ba9a0a0 100644
--- a/Components/5380/SCSI.cpp
+++ b/Components/5380/SCSI.cpp
@@ -17,19 +17,27 @@ size_t Bus::add_device() {
}
void Bus::set_device_output(size_t device, BusState output) {
- printf("%08x output\n", output);
+ if(device_states_[device] == output) return;
device_states_[device] = output;
- state_is_valid_ = false;
-}
-BusState Bus::get_state() {
- if(!state_is_valid_) return state_;
-
- state_is_valid_ = true;
+ const auto previous_state = state_;
state_ = DefaultBusState;
for(auto state: device_states_) {
state_ |= state;
}
+ if(state_ == previous_state) return;
+ printf("SCSI bus: %08x\n", state_);
+
+ for(auto &observer: observers_) {
+ observer->scsi_bus_did_change(this, state_);
+ }
+}
+
+BusState Bus::get_state() {
return state_;
}
+
+void Bus::add_observer(Observer *observer) {
+ observers_.push_back(observer);
+}
diff --git a/Components/5380/SCSI.hpp b/Components/5380/SCSI.hpp
index 69d087a6e..9e36fd586 100644
--- a/Components/5380/SCSI.hpp
+++ b/Components/5380/SCSI.hpp
@@ -70,10 +70,18 @@ class Bus {
*/
BusState get_state();
+ struct Observer {
+ virtual void scsi_bus_did_change(Bus *, BusState new_state) = 0;
+ };
+ /*!
+ Adds an observer.
+ */
+ void add_observer(Observer *);
+
private:
std::vector<BusState> device_states_;
BusState state_ = DefaultBusState;
- bool state_is_valid_ = false;
+ std::vector<Observer *> observers_;
};
}
diff --git a/Components/5380/ncr5380.cpp b/Components/5380/ncr5380.cpp
index 82fcbe75e..6f40ee9fb 100644
--- a/Components/5380/ncr5380.cpp
+++ b/Components/5380/ncr5380.cpp
@@ -12,7 +12,9 @@
using namespace NCR::NCR5380;
-NCR5380::NCR5380(int clock_rate) : clock_rate_(clock_rate) {
+NCR5380::NCR5380(int clock_rate) :
+ device_(bus_, 6),
+ clock_rate_(clock_rate) {
device_id_ = bus_.add_device();
}
@@ -28,16 +30,17 @@ void NCR5380::write(int address, uint8_t value) {
LOG("[SCSI 1] Initiator command register set: " << PADHEX(2) << int(value));
initiator_command_ = value;
- SCSI::BusState mask = SCSI::DefaultBusState;
- if(value & 0x80) mask |= Line::Reset;
- test_mode_ = value & 0x40;
+ bus_output_ &= ~(Line::Reset | Line::Acknowledge | Line::Busy | Line::SelectTarget | Line::Attention);
+ if(value & 0x80) bus_output_ |= Line::Reset;
+ if(value & 0x10) bus_output_ |= Line::Acknowledge;
+ if(value & 0x08) bus_output_ |= Line::Busy;
+ if(value & 0x04) bus_output_ |= Line::SelectTarget;
+ if(value & 0x02) bus_output_ |= Line::Attention;
+
/* bit 5 = differential enable if this were a 5381 */
- if(value & 0x10) mask |= Line::Acknowledge;
- if(value & 0x08) mask |= Line::Busy;
- if(value & 0x04) mask |= Line::SelectTarget;
- if(value & 0x02) mask |= Line::Attention;
+
+ test_mode_ = value & 0x40;
assert_data_bus_ = value & 0x01;
- bus_output_ = (bus_output_ & ~(Line::Reset | Line::Acknowledge | Line::Busy | Line::SelectTarget | Line::Attention)) | mask;
} break;
case 2:
@@ -74,9 +77,14 @@ void NCR5380::write(int address, uint8_t value) {
}
break;
- case 3:
+ case 3: {
LOG("[SCSI 3] Set target command: " << PADHEX(2) << int(value));
- break;
+ bus_output_ &= ~(Line::Request | Line::Message | Line::Control | Line::Input);
+ if(value & 0x08) bus_output_ |= Line::Request;
+ if(value & 0x04) bus_output_ |= Line::Message;
+ if(value & 0x02) bus_output_ |= Line::Control;
+ if(value & 0x01) bus_output_ |= Line::Input;
+ } break;
case 4:
LOG("[SCSI 4] Set select enabled: " << PADHEX(2) << int(value));
@@ -133,9 +141,15 @@ uint8_t NCR5380::read(int address) {
LOG("[SCSI 2] Get mode");
return mode_;
- case 3:
+ case 3: {
LOG("[SCSI 3] Get target command");
- return 0xff;
+ const auto bus_state = bus_.get_state();
+ return
+ ((bus_state & SCSI::Line::Request) ? 0x08 : 0x00) |
+ ((bus_state & SCSI::Line::Message) ? 0x04 : 0x00) |
+ ((bus_state & SCSI::Line::Control) ? 0x02 : 0x00) |
+ ((bus_state & SCSI::Line::Input) ? 0x01 : 0x00);
+ }
case 4: {
LOG("[SCSI 4] Get current bus state");
diff --git a/Components/5380/ncr5380.hpp b/Components/5380/ncr5380.hpp
index 57ce6510a..b9b551a7b 100644
--- a/Components/5380/ncr5380.hpp
+++ b/Components/5380/ncr5380.hpp
@@ -12,6 +12,7 @@
#include <cstdint>
#include "SCSI.hpp"
+#include "DirectAccessDevice.hpp"
#include "../../ClockReceiver/ClockReceiver.hpp"
#include "../../ClockReceiver/ClockingHintSource.hpp"
@@ -52,8 +53,12 @@ class NCR5380 final: public ClockingHint::Source {
ClockingHint::Preference preferred_clocking() final;
private:
- const int clock_rate_;
+ // TEMPORARY. For development expediency, the 5380 owns its own
+ // SCSI bus and direct access device. These will be moved out.
SCSI::Bus bus_;
+ SCSI::DirectAccessDevice device_;
+
+ const int clock_rate_;
size_t device_id_;
SCSI::BusState bus_output_ = SCSI::DefaultBusState;
diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
index e95f436e2..58c2dc5f7 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
@@ -619,6 +619,7 @@
4BB73EAC1B587A5100552FC2 /* MainMenu.xib in Resources */ = {isa = PBXBuildFile; fileRef = 4BB73EAA1B587A5100552FC2 /* MainMenu.xib */; };
4BB73EB71B587A5100552FC2 /* AllSuiteATests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4BB73EB61B587A5100552FC2 /* AllSuiteATests.swift */; };
4BB73EC21B587A5100552FC2 /* Clock_SignalUITests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4BB73EC11B587A5100552FC2 /* Clock_SignalUITests.swift */; };
+ 4BB8F5272308E5A50015C2A6 /* DirectAccessDevice.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BB8F5252308E5A50015C2A6 /* DirectAccessDevice.cpp */; };
4BBB70A4202011C2002FE009 /* MultiMediaTarget.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BBB70A3202011C2002FE009 /* MultiMediaTarget.cpp */; };
4BBB70A5202011C2002FE009 /* MultiMediaTarget.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BBB70A3202011C2002FE009 /* MultiMediaTarget.cpp */; };
4BBB70A8202014E2002FE009 /* MultiCRTMachine.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4BBB70A6202014E2002FE009 /* MultiCRTMachine.cpp */; };
@@ -1407,6 +1408,8 @@
4BB73EC11B587A5100552FC2 /* Clock_SignalUITests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Clock_SignalUITests.swift; sourceTree = "<group>"; };
4BB73EC31B587A5100552FC2 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
4BB73ECF1B587A6700552FC2 /* Clock Signal.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.xml; path = "Clock Signal.entitlements"; sourceTree = "<group>"; };
+ 4BB8F5252308E5A50015C2A6 /* DirectAccessDevice.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = DirectAccessDevice.cpp; sourceTree = "<group>"; };
+ 4BB8F5262308E5A50015C2A6 /* DirectAccessDevice.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = DirectAccessDevice.hpp; sourceTree = "<group>"; };
4BBB709C2020109C002FE009 /* DynamicMachine.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = DynamicMachine.hpp; sourceTree = "<group>"; };
4BBB70A2202011C2002FE009 /* MultiMediaTarget.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = MultiMediaTarget.hpp; sourceTree = "<group>"; };
4BBB70A3202011C2002FE009 /* MultiMediaTarget.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = MultiMediaTarget.cpp; sourceTree = "<group>"; };
@@ -3333,6 +3336,8 @@
4BDACBEB22FFA5D20045EF7E /* ncr5380.hpp */,
4B89BCFA23024BB500EA0782 /* SCSI.cpp */,
4B89BCFB23024BB500EA0782 /* SCSI.hpp */,
+ 4BB8F5252308E5A50015C2A6 /* DirectAccessDevice.cpp */,
+ 4BB8F5262308E5A50015C2A6 /* DirectAccessDevice.hpp */,
);
path = 5380;
sourceTree = "<group>";
@@ -4143,6 +4148,7 @@
4BCE0060227D39AB000CA200 /* Video.cpp in Sources */,
4B4518A51F75FD1C00926311 /* SSD.cpp in Sources */,
4B55CE5F1C3B7D960093A61B /* MachineDocument.swift in Sources */,
+ 4BB8F5272308E5A50015C2A6 /* DirectAccessDevice.cpp in Sources */,
4B2B3A4C1F9B8FA70062DABF /* MemoryFuzzer.cpp in Sources */,
4B7913CC1DFCD80E00175A82 /* Video.cpp in Sources */,
4BDA00E622E699B000AC3CD0 /* CSMachine.mm in Sources */,