Add support for "hi-z when low" outputs

The apple 1 CLEAR input requires a high-impedance inactive state to avoid
conflict with the pin output of the 7404 at D12 (via CR4). So, to cover this
condition most generally, this patch changes the adds a Hi-Z when low physical
device for each output line, to complement the Hi-Z-when-high open collector
emulation. The nomenclature is changed from OUT*_OC (emulated open collector) to
OUT*_OPEN_HI and OUT*_OPEN_LO to indicate which condition gets the Hi-Z state.

- added the set() functions to the asdf_arch_atmega328p.[ch] files and applied
the above nomenclature.

- Added the set() functions to the asdf_physical.[ch] files and applied the
above nomenclature

- Modified the SCREEN_CLEAR device to PHYSICAL_OUT1_OPEN_LO in the apple2 and
ascii keymaps.

- Changed the RESET from PHYSICAL_OUT1_OC to PHYSICAL_OUT1_OPEN_HI in the apple2
and ascii keymaps.

firmware/asdf/src/Arch/asdf_arch_atmega328p.c

@@ -324,7 +324,7 @@ void asdf_arch_out1_set(uint8_t value)
   set_bit(&ASDF_OUT1_DDR, ASDF_OUT1_BIT);
 }
 
-// PROCEDURE: asdf_arch_out1_hi_z_set
+// PROCEDURE: asdf_arch_out1_open_hi_set
 // INPUTS: (uint8_t) value
 // OUTPUTS: none
 //
@@ -338,7 +338,7 @@ void asdf_arch_out1_set(uint8_t value)
 //
 // COMPLEXITY: 2
 //
-void asdf_arch_out1_hi_z_set(uint8_t value)
+void asdf_arch_out1_open_hi_set(uint8_t value)
 {
   if (value) {
     clear_bit(&ASDF_OUT1_DDR, ASDF_OUT1_BIT);
@@ -350,6 +350,32 @@ void asdf_arch_out1_hi_z_set(uint8_t value)
   }
 }
 
+// PROCEDURE: asdf_arch_out1_open_lo_set
+// INPUTS: (uint8_t) value
+// OUTPUTS: none
+//
+// DESCRIPTION: Sets the OUT1 bit to high if value is true, and hi-z if value is false.
+//
+// SIDE EFFECTS: See above.
+//
+// NOTES:
+//
+// SCOPE: public
+//
+// COMPLEXITY: 2
+//
+void asdf_arch_out1_open_lo_set(uint8_t value)
+{
+  if (value) {
+    set_bit(&ASDF_OUT1_PORT, ASDF_OUT1_BIT);
+    set_bit(&ASDF_OUT1_DDR, ASDF_OUT1_BIT);
+  }
+  else {
+    clear_bit(&ASDF_OUT1_DDR, ASDF_OUT1_BIT);
+    clear_bit(&ASDF_OUT1_PORT, ASDF_OUT1_BIT);
+  }
+}
+
 // PROCEDURE: asdf_arch_out2_set
 // INPUTS: (uint8_t) value
 // OUTPUTS: none
@@ -395,7 +421,7 @@ void asdf_arch_null_output(uint8_t value)
   (void) value;
 }
 
-// PROCEDURE: asdf_arch_out2_hi_z_set
+// PROCEDURE: asdf_arch_out2_open_hi_set
 // INPUTS: (uint8_t) value
 // OUTPUTS: none
 //
@@ -409,7 +435,26 @@ void asdf_arch_null_output(uint8_t value)
 //
 // COMPLEXITY: 2
 //
-void asdf_arch_out2_hi_z_set(uint8_t value)
+void asdf_arch_out2_open_hi_set(uint8_t value)
+{
+  asdf_arch_null_output(value);
+}
+
+// PROCEDURE: asdf_arch_out2_open_lo_set
+// INPUTS: (uint8_t) value
+// OUTPUTS: none
+//
+// DESCRIPTION: Sets the OUT2 bit to high if value is true, and hi-z if value is false.
+//
+// SIDE EFFECTS: See above.
+//
+// NOTES: Not supported for the ATMega-328 ASCII interface.
+//
+// SCOPE: public
+//
+// COMPLEXITY: 2
+//
+void asdf_arch_out2_open_lo_set(uint8_t value)
 {
   asdf_arch_null_output(value);
 }
@@ -439,7 +484,7 @@ void asdf_arch_out3_set(uint8_t value)
   set_bit(&ASDF_OUT3_DDR, ASDF_OUT3_BIT);
 }
 
-// PROCEDURE: asdf_arch_out3_hi_z_set
+// PROCEDURE: asdf_arch_out3_open_hi_set
 // INPUTS: (uint8_t) value
 // OUTPUTS: none
 //
@@ -453,7 +498,7 @@ void asdf_arch_out3_set(uint8_t value)
 //
 // COMPLEXITY: 2
 //
-void asdf_arch_out3_hi_z_set(uint8_t value)
+void asdf_arch_out3_open_hi_set(uint8_t value)
 {
   if (value) {
     clear_bit(&ASDF_OUT3_DDR, ASDF_OUT3_BIT);
@@ -465,6 +510,32 @@ void asdf_arch_out3_hi_z_set(uint8_t value)
   }
 }
 
+// PROCEDURE: asdf_arch_out3_open_lo_set
+// INPUTS: (uint8_t) value
+// OUTPUTS: none
+//
+// DESCRIPTION: Sets the OUT3 bit to high if value is true, and hi-z if value is false.
+//
+// SIDE EFFECTS: See above.
+//
+// NOTES:
+//
+// SCOPE: public
+//
+// COMPLEXITY: 2
+//
+void asdf_arch_out3_open_lo_set(uint8_t value)
+{
+  if (value) {
+    set_bit(&ASDF_OUT3_PORT, ASDF_OUT3_BIT);
+    set_bit(&ASDF_OUT3_DDR, ASDF_OUT3_BIT);
+  }
+  else {
+    clear_bit(&ASDF_OUT3_DDR, ASDF_OUT3_BIT);
+    clear_bit(&ASDF_OUT3_PORT, ASDF_OUT3_BIT);
+  }
+}
+
 // PROCEDURE: asdf_arch_init_strobe
 // INPUTS: none
 // OUTPUTS: none

firmware/asdf/src/Arch/asdf_arch_atmega328p.h

@@ -279,11 +279,17 @@ void asdf_arch_led3_set(uint8_t value);
 // DESCRIPTION: Sets the OUT1 bit if value is true, and clear OUT1 if value is false.
 void asdf_arch_out1_set(uint8_t value);
 
-// PROCEDURE: asdf_arch_out1_hi_z_set
+// PROCEDURE: asdf_arch_out1_open_hi_set
 // INPUTS: (uint8_t) value
 // OUTPUTS: none
 // DESCRIPTION: Sets the OUT1 bit to hi-z if value is true, and low if value is false.
-void asdf_arch_out1_hi_z_set(uint8_t value);
+void asdf_arch_out1_open_hi_set(uint8_t value);
+
+// PROCEDURE: asdf_arch_out1_open_lo_set
+// INPUTS: (uint8_t) value
+// OUTPUTS: none
+// DESCRIPTION: Sets the OUT1 bit to hi-z if value is true, and low if value is false.
+void asdf_arch_out1_open_lo_set(uint8_t value);
 
 // PROCEDURE: asdf_arch_out2_set
 // INPUTS: (uint8_t) value
@@ -291,25 +297,36 @@ void asdf_arch_out1_hi_z_set(uint8_t value);
 // DESCRIPTION: Sets the OUT2 bit if value is true, and clear OUT2 if value is false.
 void asdf_arch_out2_set(uint8_t value);
 
+// PROCEDURE: asdf_arch_out2_open_hi_set
+// INPUTS: (uint8_t) value
+// OUTPUTS: none
+// DESCRIPTION: Sets the OUT2 bit to hi-z if value is true, and low if value is false.
+// NOTES: Not supported for the ATMega-328 ASCII interface.
+void asdf_arch_out2_open_hi_set(uint8_t value);
+
+// PROCEDURE: asdf_arch_out2_open_lo_set
+// INPUTS: (uint8_t) value
+// OUTPUTS: none
+// DESCRIPTION: Sets the OUT2 bit to high if value is true, and hi-z if value is false.
+void asdf_arch_out2_open_lo_set(uint8_t value);
+
 // PROCEDURE: asdf_arch_out3_set
 // INPUTS: (uint8_t) value
 // OUTPUTS: none
 // DESCRIPTION: Sets the OUT3 bit if value is true, and clear OUT3 if value is false.
 void asdf_arch_out3_set(uint8_t value);
 
-// PROCEDURE: asdf_arch_out2_hi_z_set
+// PROCEDURE: asdf_arch_out3_open_hi_set
-// INPUTS: (uint8_t) value
-// OUTPUTS: none
-// DESCRIPTION: Sets the OUT2 bit to hi-z if value is true, and low if value is false.
-// NOTES: Not supported for the ATMega-328 ASCII interface.
-void asdf_arch_out2_hi_z_set(uint8_t value);
-
-
-// PROCEDURE: asdf_arch_out3_hi_z_set
 // INPUTS: (uint8_t) value
 // OUTPUTS: none
 // DESCRIPTION: Sets the OUT3 bit to hi-z if value is true, and low if value is false.
-void asdf_arch_out3_hi_z_set(uint8_t value);
+void asdf_arch_out3_open_hi_set(uint8_t value);
+
+// PROCEDURE: asdf_arch_out3_open_lo_set
+// INPUTS: (uint8_t) value
+// OUTPUTS: none
+// DESCRIPTION: Sets the OUT3 bit to hi-z if value is true, and low if value is false.
+void asdf_arch_out3_open_lo_set(uint8_t value);
 
 // PROCEDURE: asdf_arch_read_row
 // INPUTS: (uint8_t) row: the row number to be scanned

firmware/asdf/src/Keymaps/asdf_keymap_defs_apple2.h

@@ -49,12 +49,12 @@
 
 #define ACTION_RESET ACTION_VOUT1
 #define VIRTUAL_RESET VOUT1
-#define RESET_OUTPUT PHYSICAL_OUT3_OC
+#define RESET_OUTPUT PHYSICAL_OUT3_OPEN_HI
 #define RESET_ACTIVE_VALUE 0
 
 #define ACTION_CLEAR ACTION_VOUT2
 #define VIRTUAL_CLR_SCR VOUT2
-#define CLR_SCR_OUTPUT PHYSICAL_OUT1
+#define CLR_SCR_OUTPUT PHYSICAL_OUT1_OPEN_LO
 #define CLR_SCR_ACTIVE_VALUE 1
 
 #define VIRTUAL_POWER_LED VLED1

firmware/asdf/src/Keymaps/asdf_keymap_defs_ascii.h

@@ -40,11 +40,11 @@
 #define ACTION_BREAK ACTION_NOTHING
 
 #define VIRTUAL_RESET VOUT1
-#define RESET_OUTPUT PHYSICAL_OUT3_OC
+#define RESET_OUTPUT PHYSICAL_OUT3_OPEN_HI
 #define RESET_ACTIVE_VALUE 0
 
 #define VIRTUAL_CLR_SCR VOUT2
-#define CLR_SCR_OUT PHYSICAL_OUT1
+#define CLR_SCR_OUT PHYSICAL_OUT1_OPEN_LO
 #define CLR_SCR_ACTIVE_VALUE 1
 
 #define VIRTUAL_POWER_LED VLED1

firmware/asdf/src/asdf_physical.c

@@ -37,9 +37,12 @@ static void (*const physical_out_set[])(uint8_t) = {
   [PHYSICAL_OUT1] = &asdf_arch_out1_set,         //
   [PHYSICAL_OUT2] = &asdf_arch_out2_set,         //
   [PHYSICAL_OUT3] = &asdf_arch_out3_set,         //
-  [PHYSICAL_OUT1_OC] = &asdf_arch_out1_hi_z_set, //
+  [PHYSICAL_OUT1_OPEN_HI] = &asdf_arch_out1_open_hi_set, //
-  [PHYSICAL_OUT2_OC] = &asdf_arch_out2_hi_z_set, //
+  [PHYSICAL_OUT2_OPEN_HI] = &asdf_arch_out2_open_hi_set, //
-  [PHYSICAL_OUT3_OC] = &asdf_arch_out3_hi_z_set, //
+  [PHYSICAL_OUT3_OPEN_HI] = &asdf_arch_out3_open_hi_set, //
+  [PHYSICAL_OUT1_OPEN_LO] = &asdf_arch_out1_open_lo_set, //
+  [PHYSICAL_OUT2_OPEN_LO] = &asdf_arch_out2_open_lo_set, //
+  [PHYSICAL_OUT3_OPEN_LO] = &asdf_arch_out3_open_lo_set, //
   [PHYSICAL_LED1] = &asdf_arch_led1_set,         //
   [PHYSICAL_LED2] = &asdf_arch_led2_set,         //
   [PHYSICAL_LED3] = &asdf_arch_led3_set          //

firmware/asdf/src/asdf_physical.h

@@ -34,11 +34,14 @@
 typedef enum {
   PHYSICAL_NO_OUT = 0,
   PHYSICAL_OUT1,
-  PHYSICAL_OUT1_OC,
+  PHYSICAL_OUT1_OPEN_HI,
+  PHYSICAL_OUT1_OPEN_LO,
   PHYSICAL_OUT2,
-  PHYSICAL_OUT2_OC,
+  PHYSICAL_OUT2_OPEN_HI,
+  PHYSICAL_OUT2_OPEN_LO,
   PHYSICAL_OUT3,
-  PHYSICAL_OUT3_OC,
+  PHYSICAL_OUT3_OPEN_HI,
+  PHYSICAL_OUT3_OPEN_LO,
   PHYSICAL_LED1,
   PHYSICAL_LED2,
   PHYSICAL_LED3,