Minor fixes to LTK to emulate hardware better

git-svn-id: https://svn.code.sf.net/p/vice-emu/code/trunk@44161 379a1393-f5fb-40a0-bcee-ef074d9b53f7

vice/src/c128/functionrom.c

@@ -40,7 +40,8 @@
 #include "types.h"
 #include "util.h"
 #include "viciitypes.h"
-
+#include "cartridge.h"
+#include "ltkernal.h"
 
 #define INTERNAL_FUNCTION_ROM_SIZE 0x8000
 
@@ -201,6 +202,13 @@ static int functionrom_load_internal(void)
 
 uint8_t internal_function_rom_read(uint16_t addr)
 {
+    /* LTK MMU modification prioritises over internal function rom */
+    if (cartridge_get_id(0) == CARTRIDGE_LT_KERNAL) {
+        if (c128ltkernal_ram_read(addr, &(vicii.last_cpu_val))) {
+            return vicii.last_cpu_val;
+        }
+    }
+
     if (internal_function_rom_enabled == INT_FUNCTION_RTC) {
         vicii.last_cpu_val = bq4830y_read(rtc1_context, (uint16_t)(addr & 0x7fff));
     } else {
@@ -222,6 +230,12 @@ uint8_t internal_function_rom_peek(uint16_t addr)
 void internal_function_rom_store(uint16_t addr, uint8_t value)
 {
     vicii.last_cpu_val = value;
+    /* LTK MMU modification prioritises over internal function rom */
+    if (cartridge_get_id(0) == CARTRIDGE_LT_KERNAL) {
+        if (c128ltkernal_ram_store(addr, value)) {
+            return;
+        }
+    }
     if (internal_function_rom_enabled == INT_FUNCTION_RTC) {
         bq4830y_store(rtc1_context, (uint16_t)(addr & 0x7fff), value);
         ram_store(addr, value);

vice/src/c64/cart/ltkernal.c

@@ -212,9 +212,7 @@ that area.
 $DF04 - $DF07:
 
 The LTK Port can be between 0 and 15. Only adaptors set to port 0 are allowed
-to change the host configuration. Any writes to this register while PB2.6 and
-CB2 are high (1), will result in the Lt. Kernal Host Adaptor being removed
-from the bus until a hard reset, essentially reconfiguring to a stock system.
+to change the host configuration.
 
     bit  meaning
     ---  -------
@@ -756,7 +754,6 @@ static void ltk_set_cb2(mc6821_state *ctx)
             LOG2((LOG, "LTK RESET SCHEDULED at 0x%04x", reg_pc));
             ltk_alarm_time = maincpu_clk + 57;
             alarm_set(ltk_alarm, ltk_alarm_time);
-/*        machine_trigger_reset(MACHINE_RESET_MODE_SOFT); */
         }
     }
 }
@@ -769,6 +766,8 @@ static void ltkernal_io_store(uint16_t addr, uint8_t value)
         IDBG((LOG, "--------------------"));
         if (addr & 0x4) {
             /* any writes to 4, 5, 6 or 7 turn off LTK I/O until reset */
+/* it turns out nothing happens when you write here. */
+/*
             if (ltk_ramwrite) {
                 ltk_on = 0;
                 ltk_ramwrite = 0;
@@ -777,6 +776,7 @@ static void ltkernal_io_store(uint16_t addr, uint8_t value)
                 ltk_ramh = 0;
                 LOG1((LOG, "LTK OFF at %04x", reg_pc));
             }
+*/
         } else {
             port = (addr >> 1) & 1; /* rs1 */
             reg = (addr >> 0) & 1;  /* rs0 */