all repos — xyw @ 481fe7eafa064f39b9ea831d00de282712f3ef06

A minimal virtual machine and assembler for terminals.

Attempting to draw pixels.
h3rald h3rald@h3rald.com
Mon, 19 Jan 2026 14:56:54 +0100
commit

481fe7eafa064f39b9ea831d00de282712f3ef06

parent

59937d38477dd125a90bdfb890b9f58ccec1e896

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

jump to
M devices/display.c → devices/display.c 
@@ -1,6 +1,8 @@ 
 #include <stdio.h>
 #include "../xyw.h"
 
+#define COLOR 0xFFFFFF
+
 /* display device */
 #define DISPLAY_FILL 0x40
 #define DISPLAY_X 0x41

@@ -12,6 +14,13 @@ {
     (void)error;
     (void)data;
     (void)addr;
+    printf("Display output called: addr=%02X\n", addr);
+    switch (addr)
+    {
+    case DISPLAY_FILL:
+        fenster_pixel(&xyw_fenster, data[DISPLAY_X], data[DISPLAY_Y]) = data[DISPLAY_FILL];
+        break;
+    }
 }
 
 xyw_byte display_input(xyw_byte *data, xyw_byte addr, xyw_byte *error)
M examples/devices.abs.xyw → examples/devices.abs.xyw 
@@ -34,12 +34,10 @@ .macro file.write             $FF36
 .macro file.append            $FF37
 
 ;display 
-.macro display.width          $FF40
-.macro display.height         $FF41
-.macro display.fill           $FF42
-.macro display.x              $FF43
-.macro display.y              $FF44
-.macro display.on_render      $FF45
+.macro display.fill           $FF40
+.macro display.x              $FF41
+.macro display.y              $FF42
+.macro display.on_render      $FF43
 
 ;beeper
 .macro beeper.state           $FF50
M examples/devices.xyw → examples/devices.xyw 
@@ -34,12 +34,10 @@ .macro file.write             $36
 .macro file.append            $37
 
 ;display 
-.macro display.width          $40
-.macro display.height         $41
-.macro display.fill           $42
-.macro display.x              $43
-.macro display.y              $44
-.macro display.on_render      $45
+.macro display.fill           $40
+.macro display.x              $41
+.macro display.y              $42
+.macro display.on_render      $43
 
 ;beeper
 .macro beeper.state           $50
M examples/window.xyw → examples/window.xyw 
@@ -12,3 +12,12 @@ .string "---" ; metadata marker
 
 .label init
 ; actual program starts here 
+$10 display.x STB
+$10 display.y STB
+$1 display.fill STB
+$11 display.x STB
+$10 display.y STB
+$1 display.fill STB
+$12 display.x STB
+$10 display.y STB
+$1 display.fill STB
M xywrun.c → xywrun.c 
@@ -73,14 +73,9 @@ }
 
 static inline xyw_byte get_device_address(xyw_word addr)
 {
-    // Should return a number between 0 and 15, add validation
-    xyw_byte port = (addr - DEVICE_AREA_START) % 16;
-    if (port >= 16)
-    {
-        *error = XYW_ERROR_DEVICE_UNAVAILABLE;
-        return -1;
-    }
-    return port;
+    // Given $FF40, it should return $40
+    // TODO: verify correctness
+    return (xyw_byte)(addr - DEVICE_AREA_START);
 }
 
 //// Read/write memory helpers

@@ -123,11 +118,14 @@ }
 
 static inline void write(xyw_word addr, xyw_byte val)
 {
+    printf("Write to addr=%04X val=%02X\n", addr, val);
     xyw_memory[addr] = val;
     int dev_num = get_device(addr);
+    printf("Device number: %d\n", dev_num);
     if (dev_num >= 0 && xyw_devices[dev_num].output)
     {
         xyw_byte dev_addr = get_device_address(addr);
+        printf("Device address: %02X\n", dev_addr);
         xyw_devices[dev_num].output(get_device_data(addr), dev_addr, error);
     }
 }