Epple-II/src/addressbus.cpp

/*
    epple2
    Copyright (C) 2008 by Christopher A. Mosher <cmosher01@gmail.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY, without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "addressbus.h"
#include "memory.h"
#include "memoryrandomaccess.h"
#include "keyboard.h"
#include "videomode.h"
#include "paddles.h"
#include "paddlebuttonstates.h"
#include "speakerclicker.h"
#include "cassettein.h"
#include "cassetteout.h"
#include "diskcontroller.h"
#include "slots.h"

AddressBus::AddressBus(ScreenImage& gui, int& revision, MemoryRandomAccess& ram, Memory& rom, Keyboard& kbd, VideoMode& vid, Paddles& paddles, PaddleButtonStates& paddleButtonStates, SpeakerClicker& speaker, CassetteIn& cassetteIn, CassetteOut& cassetteOut, Slots& slts):
    gui(gui), revision(revision), ram(ram), rom(rom), kbd(kbd), vid(vid), paddles(paddles), paddleButtonStates(paddleButtonStates), speaker(speaker), cassetteIn(cassetteIn), cassetteOut(cassetteOut), slts(slts), debugoutpos(0), debugfirst(true) {
}


AddressBus::~AddressBus() = default;









unsigned char AddressBus::read(const unsigned short address) {
    if ((address >> 14) == 3) { // >= $C000
        if ((address >> 12) == 0xC) {
            // 11007sss,xxxxxxxx
            const bool seventh = address & 0x0800;
            const int slot = (address >> 8) & 7;
            if (seventh) {
                this->data = this->slts.readSeventhRom(address & 0x07FF, this->data);
            } else if (slot == 0) {
                readSwitch(address & 0x00FF);
            } else {
                this->data = this->slts.readRom(slot, address & 0x00FF, this->data);
            }
        } else {
            this->data = this->slts.ioBankRom(address - 0xD000, this->data, false);
            if (!this->slts.inhibitMotherboardRom()) {
                this->data = this->rom.read(address - 0xD000, this->data);
            }
        }
    } else { // < $C000
        this->data = this->ram.read(address, this->data);
    }

    return this->data;
}

void AddressBus::write(const unsigned short address, const unsigned char d) {
    this->data = d;

    if ((address >> 14 == 3)) { // >= $C000
        if ((address >> 12) == 0xC) {
            // 11007sss,xxxxxxxx
            const bool seventh = address & 0x0800;
            const int slot = (address >> 8) & 7;
            if (!seventh && slot == 0) {
                writeSwitch(address & 0x00FF);
            }
        }
        else {
            this->data = this->slts.ioBankRom(address - 0xD000, this->data, true);
        }
    }
    else { // < $C000
        this->ram.write(address, this->data);
    }
}









void AddressBus::setD7(const bool set) {
    if (set) {
        this->data |= 0x80;
    } else {
        this->data &= 0x7F;
    }
}

void AddressBus::readSwitch(unsigned short address) {
    if (address < 0x80) {
        const int islot = (address >> 4) & 0xF;
        const int iswch = (address & 0xF);
        if (islot == 0x0) {
            this->data = this->kbd.get();
        } else if (islot == 0x1) {
            this->kbd.clear();
        } else if (islot == 0x2) {
            this->cassetteOut.output();
        } else if (islot == 0x3) {
            if (this->revision == 0) {
                this->cassetteOut.output();
            }
            this->speaker.click();
        } else if (islot == 0x4) {
            // TODO ? utility strobe
        } else if (islot == 0x5) {
            if (iswch < 0x8) {
                this->data = this->vid.io(address, this->data);
            } else {
                // 11000000,01011aaf
                // aa = annunciator, 0-3
                // f == on/off
                const bool on = iswch & 1;
                const int ann = (iswch >> 1) & 3;
                this->gui.setAnnunciator(ann, on);
            }
        } else if (islot == 0x6) {
            int sw2 = iswch & 0x7;
            if (sw2 == 0) {
                setD7(this->cassetteIn.input());
            } else if (sw2 < 4) {
                setD7(this->paddleButtonStates.isDown(sw2-1));
            } else {
                sw2 &= 3;
                setD7(!this->paddles.isTimedOut(sw2));
            }
        } else if (islot == 0x7) {
            this->paddles.startTimers();
            setD7(true);
        }
    } else {
        // slot I/O switches
        address &= 0x7F;
        const int islot = (address >> 4) & 0xF;
        const int iswch = (address & 0xF);
        this->data = this->slts.io(islot, iswch, this->data, false);
        ///////////////////////////////////////////////
        // debug raw nibble disk reads
//        if (islot==6 && ((this->data & 0x80u) != 0u)) {
//            if (debugfirst) {
//                debugfirst = false;
//                for (int i = 0; i < 128; ++i) {
//                    printf("%02X", i);
//                }
//                printf("\n");
//            }
//            printf("%02X", this->data);
//            ++debugoutpos;
//            if (128 <= debugoutpos) {
//                debugoutpos = 0;
//                printf("\n");
//                DiskController* dsk = (DiskController*)(this->slts.get(6));
//                dsk->dumpLss();
//            }
//        }
        ///////////////////////////////////////////////
    }
}

void AddressBus::writeSwitch(unsigned short address){
    if (address < 0x80)	{
        const int islot = (address >> 4) & 0xF;
        const int iswch = (address & 0xF);

        if (islot == 0x1) {
            this->kbd.clear();
        } else if (islot == 0x5) {
            if (iswch < 0x8) {
                this->vid.io(address, this->data);
            }
        }
        // ignore all other switch writes
    } else {
        // slot I/O switches
        address &= 0x7F;
        const int islot = (address >> 4) & 0xF;
        const int iswch = (address & 0xF);
        this->slts.io(islot, iswch, this->data, true);
    }
}