Emulator: separated terminal and status windows

pat80-computer/software/z80-assembly/os/tests/out_single_char.asm

@@ -0,0 +1,7 @@
+; @language: Z80 ASM
+; Simple possible code test:
+; outputs a single character "A" on IO port 0, then halts
+
+ld a,'A'
+out (1),a
+halt

pat80-emulator/.gitignore

@@ -0,0 +1,2 @@
+build
+

pat80-emulator/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.10.0)
+project(pat80-emulator VERSION 0.1.0 LANGUAGES C)
+
+add_executable(pat80-emulator main.c)
+
+find_package(Z80 REQUIRED)
+target_link_libraries(pat80-emulator Z80)
+
+find_package(Curses REQUIRED)
+include_directories(${CURSES_INCLUDE_DIR})
+target_link_libraries(pat80-emulator ${CURSES_LIBRARIES})

pat80-emulator/CMakePresets.json

@@ -0,0 +1,17 @@
+{
+    "version": 8,
+    "configurePresets": [
+        {
+            "name": "gcc",
+            "displayName": "GCC 14.2.1 x86_64-pc-linux-gnu",
+            "description": "Using compilers: C = /usr/bin/gcc, CXX = /usr/bin/g++",
+            "binaryDir": "${sourceDir}/out/build/${presetName}",
+            "cacheVariables": {
+                "CMAKE_INSTALL_PREFIX": "${sourceDir}/out/install/${presetName}",
+                "CMAKE_C_COMPILER": "/usr/bin/gcc",
+                "CMAKE_CXX_COMPILER": "/usr/bin/g++",
+                "CMAKE_BUILD_TYPE": "Debug"
+            }
+        }
+    ]
+}

pat80-emulator/README.md

@@ -1,7 +1,19 @@
-# PAT80 Emulator
-This folder contains a submodule (you should fetch it if you need to run the os in an emulator).
+# Pat80 emulator
 
-Uses cburbridge's Z80 emulator written in python. It opens some windows showing the emulated computer's memory map, the cpu registers state and parallel terminal to interact with the os.
+## Setup
+
+Install the required Z80 emulator by redcode following the instructions for your Linux distribution at https://github.com/redcode/Z80
+Make sure to install not only the `libz80` package, but also `libz80-dev`.
+
+Create the build directory: `mkdir build`
+Create the makefile with cmake: `cd build && cmake ..`
+
+## Build
+
+Enter the `build` directory and run `make`.
+An executable file named `pat80-emulator` is created.
 
 ## Usage
-To run the os in the emulator, head to `pat80-computer/software/z80-assembly/os/Makefile` and run `make run` to build the rom from assembly and start the emulator.
+
+Enter the `build` directory
+Run `./pat80-emulator`

pat80-emulator/main.c

@@ -0,0 +1,256 @@
+/**
+ * PAT80 Emulator
+ *
+ * Emulates a PAT80.
+ */
+
+#include <Z/constants/pointer.h> /* Z_NULL */
+#include <Z80.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ncurses.h>
+
+#define ROM_SIZE         0x8000 /* 32 KiB */
+#define MEMORY_SIZE      0xFFFF /* 64 KiB */
+#define TERMINAL_WIDTH   60
+#define TERMINAL_HEIGHT  25
+#define SPACING_BETWEEN_WINDOWS 3
+#define INSTRUCTION_WINDOW_HEIGHT 3
+
+typedef struct {
+        void* context;
+        zuint8 (* read)(void *context);
+        void (* write)(void *context, zuint8 value);
+} Device;
+
+typedef struct {
+        zusize  cycles;
+        zuint8  memory[65536];
+        Z80     cpu;
+        WINDOW  *terminal_win;
+        WINDOW  *status_win;
+} Machine;
+
+
+static zuint8 machine_cpu_read(Machine *self, zuint16 address) {
+        return address < MEMORY_SIZE ? self->memory[address] : 0xFF;
+}
+
+
+static void machine_cpu_write(Machine *self, zuint16 address, zuint8 value) {
+        if (address >= ROM_SIZE && address < MEMORY_SIZE)
+                self->memory[address] = value;
+}
+
+
+static zuint8 machine_cpu_in(Machine *self, zuint16 port) {
+	// Pat80 has 8 devices, decoded based on the 3 most significant IO addr bits.
+        // Note the Z80 has 16 bit address bus, but only the first 8 are used as IO addr,
+        // so the 3 most significant IO addr bits in this case are A7, A6, A5. The bits
+        // A4-A0 may be used by the single device, at its own discretion.
+        zuint16 bitmask = 7; // 0000000000000111
+        int decoded = port & bitmask;
+	if (decoded <= 0x1F) {
+		// Port 0 (0x00 to 0x1F): terminal
+		// Read char from stin
+                char c = getch();
+                // Intercept emulator commands
+                switch (c) {
+                        case 27:
+                                // ESC: shutdown emulator
+                                exit(0);        // TODO: Shutdown ncurses and emulator cleanly
+                                return 0;
+                        default:
+                                // Deliver keypress to pat80
+                                return c;
+                }
+        }
+        if (decoded <=  0x3F) {
+                // Port 1 (0x20 to 0x3F): sound card (sn76489)
+		wprintw(self->status_win, "sound_cmd[IN]: Not supported!\n");
+                return 0x00;
+        }
+        if (decoded <=  0x5F) {
+                // Port 2 (0x40 to 0x5F)
+                wprintw(self->status_win, "IO_ERROR_IN: No device at port 2\n");
+                return 0x00;
+        }
+        if (decoded <=  0x7F) {
+                // Port 3 (0x60 to 0x7F)
+                wprintw(self->status_win, "IO_ERROR_IN: No device at port 3\n");
+                return 0x00;
+        }
+        if (decoded <=  0x9F) {
+                // Port 4 (0x80 to 0x9F)
+                wprintw(self->status_win, "IO_ERROR_IN: No device at port 4\n");
+                return 0x00;
+        }
+        if (decoded <=  0x5F) {
+                // Port 5 (0xA0 to 0xBF)
+                wprintw(self->status_win, "IO_ERROR_IN: No device at port 5\n");
+                return 0x00;
+        }
+        if (decoded <=  0x5F) {
+                // Port 6 (0xC0 to 0xDF)
+                wprintw(self->status_win, "IO_ERROR_IN: No device at port 6\n");
+                return 0x00;
+        }
+        if (decoded <=  0x5F) {
+                // Port 7 (0xE0 to 0xFF)
+                wprintw(self->status_win, "IO_ERROR_IN: No device at port 7\n");
+        } else {
+                wprintw(self->status_win, "IO_ERROR_IN: Invalid port address: %#04x\n", port);
+        }
+
+        // TODO: place this in a refresh cycle between CPU instructions
+        refresh();
+        wrefresh(self->terminal_win);
+        wrefresh(self->status_win);
+}
+
+
+static void machine_cpu_out(Machine *self, zuint16 port, zuint8 value) {
+	// Pat80 has 8 devices, decoded based on the 3 most significant IO addr bits.
+        // Note the Z80 has 16 bit address bus, but only the first 8 are used as IO addr,
+        // so the 3 most significant IO addr bits in this case are A7, A6, A5. The bits
+        // A4-A0 may be used by the single device, at its own discretion.
+        zuint16 bitmask = 0xE0; // 0000000011100000
+        int decoded = port & bitmask;
+	if (decoded <= 0x1F) {
+		// Port 0 (0x00 to 0x1F): terminal
+		wprintw(self->terminal_win, "%c", value);
+	} else if (decoded <= 0x3F) {
+                // Port 1 (0x20 to 0x3F): sound card (sn76489)
+		wprintw(self->status_win, "sound_cmd[%#04x]\n", value);
+        } else if (decoded <= 0x5F) {
+                // Port 2 (0x40 to 0x5F)
+                wprintw(self->status_win, "IO_ERROR_OUT: No device at port 2\n");
+        } else if (decoded <= 0x7F) {
+                // Port 3 (0x60 to 0x7F)
+                wprintw(self->status_win, "IO_ERROR_OUT: No device at port 3\n");
+        } else if (decoded <= 0x9F) {
+                // Port 4 (0x80 to 0x9F)
+                wprintw(self->status_win, "IO_ERROR_OUT: No device at port 4\n");
+        } else if (decoded <= 0x5F) {
+                // Port 5 (0xA0 to 0xBF)
+                wprintw(self->status_win, "IO_ERROR_OUT: No device at port 5\n");
+        } else if (decoded <= 0x5F) {
+                // Port 6 (0xC0 to 0xDF)
+                wprintw(self->status_win, "IO_ERROR_OUT: No device at port 6\n");
+        } else if (decoded <= 0x5F) {
+                // Port 7 (0xE0 to 0xFF)
+                wprintw(self->status_win, "IO_ERROR_OUT: No device at port 7\n");
+        } else {
+                wprintw(self->status_win, "IO_ERROR_OUT: Invalid port address: %#04x\n", port);
+        }
+
+        // TODO: place this in a refresh cycle between CPU instructions
+        refresh();
+        wrefresh(self->terminal_win);
+        wrefresh(self->status_win);
+}
+
+
+void machine_initialize(Machine *self) {
+        self->cpu.context      = self;
+        self->cpu.fetch_opcode =
+        self->cpu.fetch        =
+        self->cpu.nop          =
+        self->cpu.read         = (Z80Read )machine_cpu_read;
+        self->cpu.write        = (Z80Write)machine_cpu_write;
+        self->cpu.in           = (Z80Read )machine_cpu_in;
+        self->cpu.out          = (Z80Write)machine_cpu_out;
+        self->cpu.halt         = Z_NULL;
+        self->cpu.nmia         = Z_NULL;
+        self->cpu.inta         = Z_NULL;
+        self->cpu.int_fetch    = Z_NULL;
+        self->cpu.ld_i_a       = Z_NULL;
+        self->cpu.ld_r_a       = Z_NULL;
+        self->cpu.reti         = Z_NULL;
+        self->cpu.retn         = Z_NULL;
+        self->cpu.hook         = Z_NULL;
+        self->cpu.illegal      = Z_NULL;
+        self->cpu.options      = Z80_MODEL_ZILOG_NMOS;
+}
+
+
+void machine_power(Machine *self, zbool state) {
+        if (state)
+                {
+                self->cycles = 0;
+                memset(self->memory, 0, MEMORY_SIZE);
+                }
+
+        z80_power(&self->cpu, state);
+}
+
+
+void machine_reset(Machine *self) {
+        z80_instant_reset(&self->cpu);
+}
+
+void machine_run(Machine *self) {
+        z80_run(&self->cpu, Z80_MAXIMUM_CYCLES);
+}
+
+int main(int argc, char *argv[]) {
+        // Parse arguments
+        if (argc < 2) {
+                printf("Usage: %s [romFile]\n", argv[0]);
+                exit(0);
+        }
+        char* romFilePath = argv[1];
+
+
+        // Init ncurses
+	initscr();			// Start curses mode
+	raw();				// Line buffering disabled (get character without waiting for ENTER key)
+	keypad(stdscr, TRUE);		// We get F1, F2 etc..
+	noecho();			// Don't echo() while we do getch
+        start_color();                  // Use colors
+        init_pair(1, COLOR_WHITE, COLOR_BLUE); // Terminal window color
+        init_pair(2, COLOR_YELLOW, COLOR_BLACK); // Status window color
+        int x,y;
+        getmaxyx(stdscr, y,x);
+
+        // Setup virtual Pat80 computer
+        Z80 pat80Cpu = {};
+        Machine pat80 = {
+                /*zusize*/  .cycles = 0,
+                /*Z80*/     .cpu = pat80Cpu,
+                .terminal_win = newwin(TERMINAL_HEIGHT, TERMINAL_WIDTH, INSTRUCTION_WINDOW_HEIGHT, 0),
+                .status_win = newwin(y, x - TERMINAL_WIDTH - SPACING_BETWEEN_WINDOWS, INSTRUCTION_WINDOW_HEIGHT, TERMINAL_WIDTH + SPACING_BETWEEN_WINDOWS)
+        };
+
+        wbkgd(pat80.terminal_win, COLOR_PAIR(1));       // Ncurses: set terminal window color
+        wbkgd(pat80.status_win, COLOR_PAIR(2));
+        scrollok(pat80.terminal_win, TRUE);             // Ncurses: Allow scrolling when reached end of window
+        scrollok(pat80.status_win, TRUE);
+        attron(A_BOLD);                                 // Print instructions
+        printw("Emulator commands\n");
+        attroff(A_BOLD);
+        printw("ESC: Exit");
+
+        machine_initialize(&pat80);
+        machine_power(&pat80, Z_TRUE);
+
+        // Load ROM into memory
+        FILE *romFile;
+        romFile = fopen(romFilePath,"rb");
+        if (romFile == NULL) {
+                printf("Unable to open rom file at %s", romFilePath);
+                exit(1);
+        }
+        fread(&pat80.memory,ROM_SIZE,1,romFile); // load rom from file into memory, up >
+        fclose(romFile);
+
+        // Start emulated computer
+        machine_reset(&pat80);
+        machine_run(&pat80);
+
+        // Stop ncurses
+        delwin(pat80.terminal_win);
+        delwin(pat80.status_win);
+        endwin();
+        return 0;
+}

pat80-emulator/z80-python-emulator

@@ -1 +0,0 @@
-Subproject commit 46d5391d5c890b2608389db5f2e8e470ef99f254