all repos — xyw @ ac1f94ffa2f5688734e4b0cf1557c3ecba1a4608

A minimal virtual machine and assembler for terminals.

Simplified device management.
h3rald h3rald@h3rald.com
Thu, 04 Dec 2025 09:15:20 +0100
commit

ac1f94ffa2f5688734e4b0cf1557c3ecba1a4608

parent

7ef6eed3ff9ebdc20cb6fbfe95113d4c2abfe2f6

1 files changed, 20 insertions(+), 32 deletions(-)

jump to
M xywrun.c → xywrun.c 
@@ -55,7 +55,7 @@ xyw_word *xw = &xw_storage;
 xyw_word *yw = &yw_storage;
 
 //// Helpers to retrieve device number and address within the device
-static inline xyw_byte get_device(xyw_word addr)
+static inline int get_device(xyw_word addr)
 {
     return (addr - DEVICE_AREA_START) / 16;
 }

@@ -81,17 +81,14 @@ //// Read/write memory helpers
 
 static inline xyw_word readw(xyw_word addr)
 {
-    if (addr >= DEVICE_AREA_START)
+    int dev_num = get_device(addr);
+    if (dev_num >= 0 && xyw_devices[dev_num].input)
     {
-        xyw_byte dev_num = get_device(addr);
-        if (xyw_devices[dev_num].input)
-        {
-            xyw_byte dev_addr = get_device_address(addr);
-            // Read two bytes from device
-            xyw_byte high = xyw_devices[dev_num].input(get_device_data(addr), dev_addr, error);
-            xyw_byte low = xyw_devices[dev_num].input(get_device_data(addr), dev_addr + 1, error);
-            return (xyw_word)((high << 8) | low);
-        }
+        xyw_byte dev_addr = get_device_address(addr);
+        // Read two bytes from device
+        xyw_byte high = xyw_devices[dev_num].input(get_device_data(addr), dev_addr, error);
+        xyw_byte low = xyw_devices[dev_num].input(get_device_data(addr), dev_addr + 1, error);
+        return (xyw_word)((high << 8) | low);
     }
     return XYW_PEEKW(&xyw_memory[addr]);
 }

@@ -99,27 +96,21 @@ 
 static inline void writew(xyw_word addr, xyw_word val)
 {
     XYW_POKEW(&xyw_memory[addr], val);
-    if (addr >= DEVICE_AREA_START)
+    int dev_num = get_device(addr);
+    if (dev_num >= 0 && xyw_devices[dev_num].output)
     {
-        xyw_byte dev_num = get_device(addr);
-        if (xyw_devices[dev_num].output)
-        {
-            xyw_byte dev_addr = get_device_address(addr);
-            xyw_devices[dev_num].output(get_device_data(addr), dev_addr, error);
-        }
+        xyw_byte dev_addr = get_device_address(addr);
+        xyw_devices[dev_num].output(get_device_data(addr), dev_addr, error);
     }
 }
 
 static inline xyw_byte read(xyw_word addr)
 {
-    if (addr >= DEVICE_AREA_START)
+    int dev_num = get_device(addr);
+    if (dev_num >= 0 && xyw_devices[dev_num].input)
     {
-        xyw_byte dev_num = get_device(addr);
-        if (xyw_devices[dev_num].input)
-        {
-            xyw_byte dev_addr = get_device_address(addr);
-            return xyw_devices[dev_num].input(get_device_data(addr), dev_addr, error);
-        }
+        xyw_byte dev_addr = get_device_address(addr);
+        return xyw_devices[dev_num].input(get_device_data(addr), dev_addr, error);
     }
     return xyw_memory[addr];
 }

@@ -127,14 +118,11 @@ 
 static inline void write(xyw_word addr, xyw_byte val)
 {
     xyw_memory[addr] = val;
-    if (addr >= DEVICE_AREA_START)
+    int dev_num = get_device(addr);
+    if (dev_num >= 0 && xyw_devices[dev_num].output)
     {
-        xyw_byte dev_num = get_device(addr);
-        if (xyw_devices[dev_num].output)
-        {
-            xyw_byte dev_addr = get_device_address(addr);
-            xyw_devices[dev_num].output(get_device_data(addr), dev_addr, error);
-        }
+        xyw_byte dev_addr = get_device_address(addr);
+        xyw_devices[dev_num].output(get_device_data(addr), dev_addr, error);
     }
 }