PDM: factory test control.

devices/ioctrl/amic.cpp

@@ -95,6 +95,9 @@ int AMIC::device_postinit()
             this->viacuda->assert_ctrl_line(ViaLine::CA1);
         });
 
+    // set EMMO pin status (active low)
+    this->emmo_pin = GET_BIN_PROP("emmo") ^ 1;
+
     return 0;
 }
 
@@ -156,7 +159,7 @@ uint32_t AMIC::read(uint32_t reg_start, uint32_t offset, int size)
     case AMICReg::Int_Ctrl:
         return (this->int_ctrl & 0xC0) | (this->dev_irq_lines & 0x3F);
     case AMICReg::Diag_Reg:
-        return 0xFFU; // this value allows the machine to boot normally
+        return 0xFE | this->emmo_pin;
     case AMICReg::DMA_Base_Addr_0:
     case AMICReg::DMA_Base_Addr_1:
     case AMICReg::DMA_Base_Addr_2:

devices/ioctrl/amic.h

@@ -208,6 +208,8 @@ protected:
 private:
     uint8_t imm_snd_regs[4]; // temporary storage for sound control registers
 
+    uint8_t     emmo_pin; // EMMO aka factory tester pin status, active low
+
     uint32_t    dma_base     = 0;  // DMA physical base address
     uint16_t    snd_buf_size = 0;  // sound buffer size in bytes
     uint8_t     snd_out_ctrl = 0;

machines/machinefactory.cpp

@@ -80,6 +80,7 @@ static const map<string, string> PropHelp = {
     {"fdd_wr_prot",     "toggles floppy disk's write protection"},
     {"mon_id",          "specifies which monitor to emulate"},
     {"serial_backend",  "specifies the backend for the serial port"},
+    {"emmo",            "enables/disables factory HW tests during startup"},
 };
 
 bool MachineFactory::add(const string& machine_id, MachineDescription desc)

machines/machinepdm.cpp

@@ -102,6 +102,8 @@ static const PropMap pm6100_settings = {
         new IntProperty(0, vector<uint32_t>({0, 8, 16, 32, 64, 128}))},
     {"mon_id",
         new StrProperty("HiRes12-14in", PDMBuiltinMonitorIDs)},
+    {"emmo",
+        new BinProperty(0)},
 };
 
 static vector<string> pm6100_devices = {