Co Pro 80x86: Switch from 80286/NMI to 80186/DMA

Change-Id: Ie45764747bd3b98f05b962e299eb2acf4a1c9767
hoglet67 · Mar 18, 2023 · 33bb8a6 · 33bb8a6
1 parent 585d52b
commit 33bb8a6
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Showing 5 changed files with 44 additions and 4 deletions.
diff --git a/src/copro-80186.c b/src/copro-80186.c
@@ -5,6 +5,7 @@
 #include "tube-ula.h"
 #include "cpu80186/cpu80186.h"
 #include "cpu80186/mem80186.h"
+#include "cpu80186/iop80186.h"
 #include "startup.h"
 #include "utils.h"
 
@@ -62,7 +63,8 @@ void copro_80186_emulator()
 
          // NMI is edge sensitive, so only check after mailbox activity
          if (tube_irq_copy & NMI_BIT) {
-            intcall86(2);
+            // intcall86(2);
+            x86_dma();
             tube_ack_nmi();
          }
 

diff --git a/src/cpu80186/Client86_v1_01.h b/src/cpu80186/Client86_v1_01.h
@@ -1,4 +1,4 @@
-#define PATCH_FOR_80286
+//#define PATCH_FOR_80286
 
 uint8_t Client86_v1_01[] = 
 {

diff --git a/src/cpu80186/cpu80186.c b/src/cpu80186/cpu80186.c
@@ -2266,7 +2266,7 @@ void exec86(uint32_t tube_cycles)
         break;
 
         case 0x54: /* 54 PUSH eSP */
-        push(getreg16(regsp));  // 8086 and intel 80186 have a bug where sp-2
+        push(getreg16(regsp) - 2);  // 8086 and intel 80186 have a bug where sp-2
                                 // is push on the stack. AMD 80186 and 286
                                 // onwards doesn't have the -2 bug. This bug
                                 // is used to detect the 186 by the TubeOS

diff --git a/src/cpu80186/iop80186.c b/src/cpu80186/iop80186.c
@@ -27,6 +27,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include <stdio.h>
 #include "../copro-80186.h"
 #include "iop80186.h"
+#include "mem80186.h"
 
 #ifdef INCLUDE_DEBUGGER
 #include "../cpu_debug.h"
@@ -36,6 +37,14 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #define TUBE_ACCESS(ADDRESS)	(((ADDRESS) & 0xFFF1) == 0x0080)
 #define TUBE_CONVERT(PORT) 	(((PORT) >> 1) & 0x0007)
 
+
+
+static uint32_t x86sa,x86ss,x86src;
+static uint32_t x86da,x86ds,x86dst;
+static uint32_t x86ena;
+static uint16_t x86imask=0;
+
+
 // I/O locations
 // =============
 // &80 Tube R1 Status
@@ -47,13 +56,41 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 // &8C Tube R4 Status
 // &8E Tube R4 Data
 
+void x86_dma()
+{
+    if (!(x86ena & 2)) {
+        return;
+    }        
+    if (x86src < 0x100) {
+        write86(x86dst, portin((uint16_t) x86src));
+        x86dst++;
+    } else {
+        portout((uint16_t) x86dst, read86(x86src));
+        x86src++;
+    }
+}
+
 void portout(uint16_t portnum, uint8_t value)
 {
 #ifdef INCLUDE_DEBUGGER
    if (cpu80186_debug_enabled) {
       debug_iowrite(&cpu80186_cpu_debug, portnum, value, 1);
    }
 #endif
+    switch (portnum)
+    {
+        case 0xFF28: x86imask = value; return;
+        case 0xFFC0: x86sa  = (x86sa  & 0xFF00) |  value;       x86src = x86sa + ((x86ss & 0xF) << 16); return;
+        case 0xFFC1: x86sa  = (x86sa  & 0x00FF) | (value << 8); x86src = x86sa + ((x86ss & 0xF) << 16); return;
+        case 0xFFC2: x86ss  = (x86ss  & 0xFF00) |  value;       x86src = x86sa + ((x86ss & 0xF) << 16); return;
+        case 0xFFC3: x86ss  = (x86ss  & 0x00FF) | (value << 8); x86src = x86sa + ((x86ss & 0xF) << 16); return;
+        case 0xFFC4: x86da  = (x86da  & 0xFF00) |  value;       x86dst = x86da + ((x86ds & 0xF) << 16); return;
+        case 0xFFC5: x86da  = (x86da  & 0x00FF) | (value << 8); x86dst = x86da + ((x86ds & 0xF) << 16); return;
+        case 0xFFC6: x86ds  = (x86ds  & 0xFF00) |  value;       x86dst = x86da + ((x86ds & 0xF) << 16); return;
+        case 0xFFC7: x86ds  = (x86ds  & 0x00FF) | (value << 8); x86dst = x86da + ((x86ds & 0xF) << 16); return;
+        case 0xFFCA: x86ena = (x86ena & 0xFF00) |  value;                                               return;
+        case 0xFFCB: x86ena = (x86ena & 0x00FF) | (value << 8);                                         return;
+    }
 	if (TUBE_ACCESS(portnum)) {
 		copro_80186_tube_write(TUBE_CONVERT(portnum), value);
 	}

diff --git a/src/cpu80186/iop80186.h b/src/cpu80186/iop80186.h
@@ -1,4 +1,5 @@
 extern void	portout (uint16_t portnum, uint8_t value);
 extern void	portout16 (uint16_t portnum, uint16_t value);
 extern uint8_t	portin (uint16_t portnum);
-extern uint16_t portin16 (uint16_t portnum);
+extern uint16_t portin16 (uint16_t portnum);
+extern void x86_dma();