Function control_write

core/control.c:78–213

Write to the 0x0XXX range of ports */

/* Write to the 0x0XXX range of ports */
static void control_write(const uint16_t pio, const uint8_t byte, bool poke) {
    unsigned int i;
    uint8_t index = (uint8_t)pio;
    (void)poke;

    switch (index) {
        case 0x00:
            control.ports[index] = byte & 0x93;
            if (byte & (1 << 4)) {
                cpu_crash("writing to bit 4 of port 0");
            }
            /* Setting this bit turns off the calc (not implemented yet) */
            if (byte & (1 << 6)) {
                control.off = true;
            }
            switch (control.readBatteryStatus) {
                case 3: /* Battery Level is 0 */
                    control.readBatteryStatus = control.setBatteryStatus == BATTERY_0 ? 0 : byte & 0x80 ? 5 : 0;
                    break;
                case 5: /* Battery Level is 1 */
                    control.readBatteryStatus = control.setBatteryStatus == BATTERY_1 ? 0 : byte & 0x80 ? 0 : 7;
                    break;
                case 7: /* Battery Level is 2 */
                    control.readBatteryStatus = control.setBatteryStatus == BATTERY_2 ? 0 : byte & 0x80 ? 9 : 0;
                    break;
                case 9: /* Battery Level is 3 (Or 4) */
                    control.readBatteryStatus = control.setBatteryStatus == BATTERY_3 ? 0 : byte & 0x80 ? 0 : 11;
                    break;
            }
            break;
        case 0x01:
            control.ports[index] = byte & 19;
            control.cpuSpeed = byte & 3;
            switch(control.cpuSpeed) {
                case 0:
                    set_cpu_clock(6e6);  /* 6 MHz  */
                    break;
                case 1:
                    set_cpu_clock(12e6); /* 12 MHz */
                    break;
                case 2:
                    set_cpu_clock(24e6); /* 24 MHz */
                    break;
                case 3:
                    set_cpu_clock(48e6); /* 48 MHz */
                    break;
                default:
                    break;
            }
            break;
        case 0x05:
            if ((control.ports[index] & ~byte) & (1 << 6)) {
                cpu_crash("resetting bit 6 of port 5");
            }
            control.ports[index] = byte & 0x1F;
            break;
        case 0x06:
            control.protectedPortsUnlocked = byte & 7;