AltairZ80: The Big Beautiful PR

This PR contains the following:

Adds a new SD Systems SBC200 device.
Adds a new SD Systems VFII VersaFloppy II device.
Adds ability to load HEX files at a specified address.
Adds support for SD Systems ExpandoRAM banked memory.
Adds improved DSK image support to the WD179X device.
Adds support for formats that don't include the FC index mark to WD179X WRITE_TRACK command.
Fixed WD179X VERIFY register.

This PR passes Howard's AltairZ80 tests.

Additional tests were added here:

https://github.com/deltecent/altairz80-tests/

Additional packages were added here:

https://github.com/deltecent/altairz80-packages/

Author: deltecent

AltairZ80/altairz80_cpu.c

@@ -572,6 +572,8 @@ static MTAB cpu_mod[] = {
         NULL, NULL, "Sets the RAM type to Cromemco RAM for 8080 / Z80 / 8086"   },
     { MTAB_XTD | MTAB_VDV,  4,                  NULL,           "B810",         &cpu_set_ramtype,
         NULL, NULL, "Sets the RAM type AB Digital Design B810 8080 / Z80 / 8086"},
+    { MTAB_XTD | MTAB_VDV,  5,                  NULL,           "ERAM",         &cpu_set_ramtype,
+        NULL, NULL, "Sets the RAM type to SD Systems ERAM for 8080 / Z80 / 8086"},
     { MTAB_VDV,             4,                  NULL,           "4KB",          &cpu_set_size,
         NULL, NULL, "Sets the RAM size to 4KB for 8080 / Z80 / 8086"        },
     { MTAB_VDV,             8,                  NULL,           "8KB",          &cpu_set_size,
@@ -631,8 +633,8 @@ static MTAB cpu_mod[] = {
 
 /* Simulator-specific commands */
 static CTAB cpu_cmd_tbl[] = {
-    { "MEM", &cpu_cmd_memory, 0, "MEM <address>    Dump a block of memory\n" },
-    { "REG", &cpu_cmd_reg,    0, "REG              Display registers\n" },
+    { "MEM",     &cpu_cmd_memory, 0, "MEM <address>    Dump a block of memory\n" },
+    { "REG",     &cpu_cmd_reg,    0, "REG              Display registers\n" },
     { NULL, NULL, 0, NULL }
 };
 
@@ -734,7 +736,8 @@ const char* handlerNameForPort(const int32 port) {
 #define RAM_TYPE_VRAM   2       /* Vector Graphic RAM card */
 #define RAM_TYPE_CRAM   3       /* Cromemco RAM card */
 #define RAM_TYPE_B810   4       /* AB Digital Design B810 RAM card */
-#define MAX_RAM_TYPE    RAM_TYPE_B810
+#define RAM_TYPE_ERAM   5       /* SD Systems ExpandoRAM */
+#define MAX_RAM_TYPE    RAM_TYPE_ERAM
 
 static int32 ramtype = RAM_TYPE_AZ80;
 
@@ -6760,7 +6763,7 @@ const static CPUFLAG *cpuflags[NUM_CHIP_TYPE] = { cpuflags8080, cpuflagsZ80,
     cpuflags8086, cpuflagsM68K, };
 
 /* needs to be set for each ramtype <= MAX_RAM_TYPE */
-static const char *ramTypeToString[] = { "AZ80", "HRAM", "VRAM", "CRAM", "B810" };
+static const char *ramTypeToString[] = { "AZ80", "HRAM", "VRAM", "CRAM", "B810", "ERAM" };
 
 static const char* m68kVariantToString[] = {
     "INVALID",
@@ -7000,6 +7003,13 @@ static int32 bankseldev(const int32 port, const int32 io, const int32 data) {
                     sim_printf("Invalid bank select 0x%02x for B810\n", data);
                 }
                 break;
+            case RAM_TYPE_ERAM:
+                if (data < 8) {
+                    setBankSelect(data);
+                } else {
+                    sim_printf("Invalid bank select 0x%02x for ERAM\n", data);
+                }
+                break;
             case RAM_TYPE_AZ80:
             default:
                 break;
@@ -7143,6 +7153,11 @@ static t_stat cpu_set_ramtype(UNIT *uptr, int32 value, CONST char *cptr, void *d
                 sim_printf("Unmapping AB Digital Design B810 RAM\n");
             sim_map_resource(0x40, 1, RESOURCE_TYPE_IO, &bankseldev, "bankseldev", TRUE);
             break;
+        case RAM_TYPE_ERAM:
+            if (cpu_unit.flags & UNIT_CPU_VERBOSE)
+                sim_printf("Unmapping SD Systems ExpandoRAM\n");
+            sim_map_resource(0xff, 1, RESOURCE_TYPE_IO, &bankseldev, "bankseldev", TRUE);
+            break;
         case 0:
         default:
             if (cpu_unit.flags & UNIT_CPU_VERBOSE)
@@ -7171,6 +7186,11 @@ static t_stat cpu_set_ramtype(UNIT *uptr, int32 value, CONST char *cptr, void *d
                 sim_printf("AB Digital Design B810 RAM Selected\n");
             sim_map_resource(0x40, 1, RESOURCE_TYPE_IO, &bankseldev, "bankseldev", FALSE);
             break;
+        case RAM_TYPE_ERAM:
+            if (cpu_unit.flags & UNIT_CPU_VERBOSE)
+                sim_printf("SD Systems ExpandoRAM Selected\n");
+            sim_map_resource(0xff, 1, RESOURCE_TYPE_IO, &bankseldev, "bankseldev", FALSE);
+            break;
         case 0:
         default:
             if (cpu_unit.flags & UNIT_CPU_VERBOSE)
@@ -7521,11 +7541,21 @@ static t_stat cpu_hex_load(FILE *fileref, CONST char *cptr, CONST char *fnam, in
     char linebuf[1024], datastr[1024], *bufptr;
     int32 bytecnt, rectype, databyte, chksum, line = 0, cnt = 0;
     uint32 makeROM = FALSE;
-    t_addr addr, org = 0;
+    t_addr addr, start = 0, offset = 0, org = -1;
+    CONST char *result;
 
     get_glyph(cptr, gbuf, 0);
     if (strcmp(gbuf, "ROM") == 0) {
         makeROM = TRUE;
+    } else {
+	start = strtotv(cptr, &result, 16) & ADDRMASKEXTENDED;
+        if (cptr != result)
+            org = start;
+        while (isspace(*result))
+            result++;
+        get_glyph(result, gbuf, 0);
+        if (strcmp(gbuf, "ROM") == 0)
+            makeROM = TRUE;
     }
 
     while (!feof(fileref)) {
@@ -7556,16 +7586,20 @@ static t_stat cpu_hex_load(FILE *fileref, CONST char *cptr, CONST char *fnam, in
         datastr[sizeof(datastr) - 1] = '\0';
 
         if ((rectype == 0) && (bytecnt > 0) && (addr+bytecnt <= MAXMEMORY)) {
-            if (cnt == 0)
-                org = addr;
+            if (cnt == 0) {
+                if (org == -1)
+                    org = addr;
+		else
+                    offset = org - addr;
+            }
 
             do {
                 if (sscanf(bufptr, "%2x", &databyte) != 1) {
                     return sim_messagef(SCPE_IERR, "Hex file format error at line %d\n", line);
                 }
                 bufptr += 2;
 
-                PutBYTEasROMorRAM(addr++, databyte, makeROM);
+                PutBYTEasROMorRAM(offset+addr++, databyte, makeROM);
 
                 chksum += databyte;
                 cnt++;

AltairZ80/altairz80_sys.c

@@ -87,12 +87,14 @@ extern DEVICE jairs1_dev;
 extern DEVICE jairp_dev;
 extern DEVICE mmd_dev;
 extern DEVICE mmdm_dev;
+extern DEVICE sbc200_dev;
 extern DEVICE sol20_dev;
 extern DEVICE sol20k_dev;
 extern DEVICE sol20t_dev;
 extern DEVICE sol20s_dev;
 extern DEVICE sol20p_dev;
 extern DEVICE vdm1_dev;
+extern DEVICE vfii_dev;
 
 extern DEVICE cromfdc_dev;
 extern DEVICE wd179x_dev;
@@ -166,6 +168,9 @@ DEVICE      *sim_devices[]  = {
     &djhdc_dev,
     &mmd_dev,
     &mmdm_dev,
+    /* SD Systems */
+    &sbc200_dev,
+    &vfii_dev,
     /* Processor Technology Devices */
     &sol20_dev,
     &sol20k_dev,