Added testcode for new function to switch working screen

targettest/c64/Makefile

@@ -0,0 +1,57 @@
+
+# Run 'make SYS=<target>'; or, set a SYS env.
+# var. to build for another target system.
+SYS ?= c64
+
+# Just the usual way to find out if we're
+# using cmd.exe to execute make rules.
+ifneq ($(shell echo),)
+  CMD_EXE = 1
+endif
+
+ifdef CMD_EXE
+  NULLDEV = nul:
+  DEL = -del /f
+  RMDIR = rmdir /s /q
+else
+  NULLDEV = /dev/null
+  DEL = $(RM)
+  RMDIR = $(RM) -r
+endif
+
+ifdef CC65_HOME
+  AS = $(CC65_HOME)/bin/ca65
+  CC = $(CC65_HOME)/bin/cc65
+  CL = $(CC65_HOME)/bin/cl65
+  LD = $(CC65_HOME)/bin/ld65
+else
+  AS := $(if $(wildcard ../../bin/ca65*),../../bin/ca65,ca65)
+  CC := $(if $(wildcard ../../bin/cc65*),../../bin/cc65,cc65)
+  CL := $(if $(wildcard ../../bin/cl65*),../../bin/cl65,cl65)
+  LD := $(if $(wildcard ../../bin/ld65*),../../bin/ld65,ld65)
+endif
+
+EXELIST_c64 = \
+        cbm_working_screen_test.prg
+
+ifneq ($(EXELIST_$(SYS)),)
+testcode: $(EXELIST_$(SYS))
+else
+testcode: notavailable
+endif
+
+# empty target used to skip systems that will not work with any program in this dir
+notavailable:
+ifeq ($(MAKELEVEL),0)
+	@echo "info: atari tests not available for" $(SYS)
+else
+# suppress the "nothing to be done for 'testcode' message
+	@echo > $(NULLDEV)
+endif
+
+cbm_working_screen_test.prg: cbm_working_screen_test.c pet2scrcode.s
+	$(CL) -t c64 -o $@ $? ../../lib/$(SYS).lib
+
+clean:
+	@$(DEL) cbm_working_screen_test.prg 2>$(NULLDEV)
+

targettest/c64/cbm_working_screen_test.c

@@ -0,0 +1,128 @@
+
+/* this program prints a text onto the standard screen (e.g. for C64 at $0400) and then switches the
+   working screen to another location and prints a string there. Then it checks, if both strings are found
+   at the correct memory location */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <assert.h>
+
+#include "../../include/cbm.h"
+
+
+char petscii2scrcode(char ch);
+
+
+int test_boundaries(void)
+{
+    struct testdata {
+        unsigned char screen_hi;
+        int returncode;
+    };
+
+    struct testdata testdata_input[] = {
+        0x00, EXIT_FAILURE,
+        0x04, EXIT_SUCCESS,
+        0x0c, EXIT_SUCCESS,
+        0x10, EXIT_FAILURE, // Cannot set screen to $1000-$1c00 due to shadowing
+        0x1c, EXIT_FAILURE,
+        0x20, EXIT_SUCCESS,
+        0x8c, EXIT_SUCCESS,
+        0x90, EXIT_FAILURE, // Cannot set screen to $9000-$9c00 due to shadowing
+        0x9c, EXIT_FAILURE,
+        0xa0, EXIT_SUCCESS,
+        0xc0, EXIT_SUCCESS,
+        0x02, EXIT_FAILURE, // SCREEN not aligned to $0400 boundary
+        0x41, EXIT_FAILURE,
+        0x72, EXIT_FAILURE,
+        0xc3, EXIT_FAILURE,
+    };
+
+    int i, returncode;
+
+    printf("Testing different desired workscreen destinations:\n");
+    for (i = sizeof(testdata_input)/sizeof(testdata_input[0]) - 1; i>=0; --i){
+        printf("Screen @$%04x: ", testdata_input[i].screen_hi*0x100);
+        returncode = cbm_set_working_screen(testdata_input[i].screen_hi);
+        cbm_set_working_screen(0x04);
+
+        if (returncode == EXIT_SUCCESS){
+            printf("OK\n");
+        } else {
+            printf("DENY\n");
+        }
+
+        if (returncode != testdata_input[i].returncode){
+            printf(
+                "Boundary check failed on screen hi %hhx!\n"
+                "Function cbm_set_working_screen returned %d instead of %d\n",
+                testdata_input[i].screen_hi,
+                returncode, testdata_input[i].returncode);
+
+                return EXIT_FAILURE;
+        }
+    }
+
+    return EXIT_SUCCESS;
+}
+
+
+int str_to_scrcode(char *str){
+    char* ch_ptr = str;
+
+    for (;*ch_ptr != '\0'; ++ch_ptr){
+        *ch_ptr = petscii2scrcode(*ch_ptr);
+    }
+
+    return 0;
+}
+
+
+int test_str_found_at(char *test_str, uint8_t scr_loc){
+    cbm_set_working_screen(scr_loc);
+
+    putchar(CH_HOME + 0x80);
+    puts(test_str);
+    str_to_scrcode(test_str);
+    cbm_set_working_screen(0x04);
+    if (strnicmp(test_str, (char*)(scr_loc * 0x100), strlen(test_str)) != 0){
+        printf("Failed to print to screen location at %04x", scr_loc * 0x100);
+        return -1;
+    }   
+
+    return 0;
+}
+
+
+int main(void)
+{
+    char *test_string1 = "foo";
+    char *test_string2 = "bar";
+    size_t testcase_count = 3;
+    size_t i;
+    int returncode, failed_tests = 0;
+
+    for (i = testcase_count; i>0; --i){
+        switch(i){
+        case 3:
+            returncode = test_boundaries();
+            break;
+        case 2:
+            returncode = test_str_found_at(test_string1, 0x3c);
+            break;
+        case 1:
+            returncode = test_str_found_at(test_string2, 0xc0);
+            break;
+        default:
+            assert(0);  // Should never come here
+        }
+        if (returncode == EXIT_FAILURE){
+            ++failed_tests;
+        }
+    }
+
+    return failed_tests;
+}

targettest/c64/pet2scrcode.s

@@ -0,0 +1,39 @@
+    .export _petscii2scrcode
+	
+    
+    _petscii2scrcode:
+        cmp #$20		; if A<32 then...
+		bcc ddRev
+
+		cmp #$60		; if A<96 then...
+		bcc dd1
+
+		cmp #$80		; if A<128 then...
+		bcc dd2
+
+		cmp #$a0		; if A<160 then...
+		bcc dd3
+
+		cmp #$c0		; if A<192 then...
+		bcc dd4
+
+		cmp #$ff		; if A<255 then...
+		bcc ddRev
+
+		lda #$7e		; A=255, then A=126
+		bne ddEnd
+
+	dd2:	and #$5f		; if A=96..127 then strip bits 5 and 7
+		bne ddEnd
+
+	dd3:	ora #$40		; if A=128..159, then set bit 6
+		bne ddEnd
+
+	dd4:	eor #$c0		; if A=160..191 then flip bits 6 and 7
+		bne ddEnd
+
+	dd1:	and #$3f		; if A=32..95 then strip bits 6 and 7
+		bpl ddEnd		; <- you could also do .byte $0c here
+
+	ddRev:	eor #$80		; flip bit 7 (reverse on when off and vice versa)
+	ddEnd:  rts