I/O fixed and tested

rom/extra.s

@@ -22,6 +22,8 @@ CHRIN:
         bne @file
         lda IO_KBD
         bmi @end
+        cmp #LF
+        beq @end
         jsr CHROUT ; echo
         rts
 @file:
@@ -54,6 +56,7 @@ CHROUT:
         sta IO_FILE_DESCRIPTOR
         pla
         sta IO_FILE_DATA
+        pha
         lda #IO_COMMAND_WRITE
         sta IO_FILE_COMMAND
 @wait:
@@ -62,10 +65,12 @@ CHROUT:
         beq @wait
         lda IO_FILE_STATUS
         and #FILE_STATUS_ERROR
-        beq :+
+        bne @error
-        jmp IQERR
+        pla
-:
         rts
+@error:
+        pla
+        jmp IQERR
 
 OPEN:
         jsr GETBYT
@@ -135,6 +140,7 @@ CLOSE:
         lda IO_FILE_STATUS
         and #FILE_STATUS_ERROR
         bne @error
+        jsr CLRCH
         rts
 @error:
         jmp IQERR

rom/print.s

@@ -47,8 +47,9 @@ L29B9:
         bne     L29DD
 
 LFDO:
-        lda     #LF
+        lda     #$00
         sta     POSX
+        lda     #LF
         jsr     OUTDO
 
 PRINTNULLS:

src/file.c

@@ -37,6 +37,10 @@ int closeFile(int fd) {
 }
 
 int readByte(const int fd, uint8_t *data) {
+  if (files[fd] == NULL) {
+    return STATUS_READY | STATUS_ERROR;
+  }
+
   int status = 0;
   int count = fread(data, 1, 1, files[fd]);
   // Error or EOF
@@ -54,17 +58,18 @@ int readByte(const int fd, uint8_t *data) {
 }
 
 int writeByte(const int fd, const uint8_t data) {
+  if (files[fd] == NULL) {
+    return STATUS_READY | STATUS_ERROR;
+  }
+
   int status = 0;
   int count = fwrite(&data, 1, 1, files[fd]);
   // Error or EOF
-  if (count != 1) {
+  if (count != 1 && ferror(files[fd]) != 0) {
-    int error = ferror(files[fd]);
+    return STATUS_READY | STATUS_ERROR;
-    int eof = feof(files[fd]);
-    if (error != 0) {
-      status = STATUS_ERROR;
-    } else if (eof != 0) {
-      status = STATUS_EOF;
   }
+  if (fflush(files[fd]) != 0) {
+    return STATUS_READY | STATUS_ERROR;
   }
 
   return STATUS_READY | status;

src/mem.c

@@ -64,43 +64,36 @@ void writeMemory(uint16_t address, uint8_t value, uint8_t *ram) {
       break;
 
     case FILE_COMMAND: {
-      switch (value) {
-        case COMMAND_OPEN_R: {
       ram[IO_BASE + FILE_STATUS] = 0;
 
+      switch (value) {
+        case COMMAND_OPEN_R: {
           uint16_t fileAddress = ram[IO_BASE + FILE_DATA] | ((uint16_t)ram[IO_BASE + FILE_DATA_HIGH] << 8);
 
           ram[IO_BASE + FILE_STATUS] = openFile(ram[IO_BASE + FILE_DESCRIPTOR], (const char *)&ram[fileAddress], "r");
           break;
         }
         case COMMAND_OPEN_W: {
-          ram[IO_BASE + FILE_STATUS] = 0;
-
           uint16_t fileAddress = ram[IO_BASE + FILE_DATA] | ((uint16_t)ram[IO_BASE + FILE_DATA_HIGH] << 8);
 
           ram[IO_BASE + FILE_STATUS] = openFile(ram[IO_BASE + FILE_DESCRIPTOR], (const char *)&ram[fileAddress], "w+");
           break;
         }
         case COMMAND_OPEN_A: {
-          ram[IO_BASE + FILE_STATUS] = 0;
-
           uint16_t fileAddress = ram[IO_BASE + FILE_DATA] | ((uint16_t)ram[IO_BASE + FILE_DATA_HIGH] << 8);
 
           ram[IO_BASE + FILE_STATUS] = openFile(ram[IO_BASE + FILE_DESCRIPTOR], (const char *)&ram[fileAddress], "a+");
           break;
         }
         case COMMAND_CLOSE: {
-          ram[IO_BASE + FILE_STATUS] = 0;
           ram[IO_BASE + FILE_STATUS] = closeFile(ram[IO_BASE + FILE_DESCRIPTOR]);
           break;
         }
         case COMMAND_READ: {
-          ram[IO_BASE + FILE_STATUS] = 0;
           ram[IO_BASE + FILE_STATUS] = readByte(ram[IO_BASE + FILE_DESCRIPTOR], &ram[IO_BASE + FILE_DATA]);
           break;
         }
         case COMMAND_WRITE: {
-          ram[IO_BASE + FILE_STATUS] = 0;
           ram[IO_BASE + FILE_STATUS] = writeByte(ram[IO_BASE + FILE_DESCRIPTOR], ram[IO_BASE + FILE_DATA]);
           break;
         }