diff --git a/Source/msg.cpp b/Source/msg.cpp
index d341b29a4..ba45e0820 100644
--- a/Source/msg.cpp
+++ b/Source/msg.cpp
@@ -8,7 +8,7 @@ static int sgnCurrMegaPlayer;
 static DLevel sgLevels[NUMLEVELS];
 static BYTE sbLastCmd;
 static TMegaPkt *sgpCurrPkt;
-static char sgRecvBuf[sizeof(DLevel) + 1];
+static BYTE sgRecvBuf[sizeof(DLevel) + 1];
 static BYTE sgbRecvCmd;
 static LocalLevel sgLocals[NUMLEVELS];
 static DJunk sgJunk;
@@ -198,14 +198,14 @@ void __cdecl msg_pre_packet()
 
 void __fastcall DeltaExportData(int pnum)
 {
-	char *v1;       // edi
+	BYTE *v1;       // edi
 	DObjectStr *v2; // esi
-	void *v3;       // ebx
-	void *v4;       // eax
-	void *v5;       // eax
-	void *v6;       // eax
+	BYTE *v3;       // ebx
+	BYTE *v4;       // eax
+	BYTE *v5;       // eax
+	BYTE *v6;       // eax
 	int v7;         // eax
-	void *v8;       // eax
+	BYTE *v8;       // eax
 	int v9;         // eax
 	int player_num; // [esp+0h] [ebp-Ch]
 	int v11;        // [esp+4h] [ebp-8h]
@@ -214,13 +214,13 @@ void __fastcall DeltaExportData(int pnum)
 	player_num = pnum;
 	if (sgbDeltaChanged) {
 		v11 = 0;
-		v1 = (char *)DiabloAllocPtr(4722);
+		v1 = (BYTE *)DiabloAllocPtr(4722);
 		v2 = sgLevels[0].object;
 		v3 = v1 + 1;
 		do {
-			v4 = DeltaExportItem(v3, &v2[-2794]);
+			v4 = DeltaExportItem(v3, (TCmdPItem *)&v2[-2794]);
 			v5 = DeltaExportObject(v4, v2);
-			v6 = DeltaExportMonster(v5, &v2[127]);
+			v6 = DeltaExportMonster(v5, (DMonsterStr *)&v2[127]);
 			v7 = msg_comp_level(v1, v6);
 			dthread_send_delta(player_num, (_BYTE)v11++ + CMD_DLEVEL_0, v1, v7);
 			v2 += 4721;
@@ -235,68 +235,57 @@ void __fastcall DeltaExportData(int pnum)
 }
 // 67618C: using guessed type char sgbDeltaChanged;
 
-void *__fastcall DeltaExportItem(void *dst, void *src)
+BYTE *__fastcall DeltaExportItem(BYTE *dst, TCmdPItem *src)
 {
-	_BYTE *v2;     // edi
-	_BYTE *v3;     // esi
-	signed int v4; // ebx
+	int i;
 
-	v2 = (unsigned char *)src;
-	v3 = (unsigned char *)dst;
-	v4 = 127;
-	do {
-		if (*v2 == -1) {
-			*v3++ = -1;
+	for (i = 0; i < MAXITEMS; i++) {
+		if (src->bCmd == 0xFF) {
+			*dst = 0xFF;
+			dst++;
 		} else {
-			memcpy(v3, v2, 0x16u);
-			v3 += 22;
+			memcpy(dst, src, sizeof(TCmdPItem));
+			dst += sizeof(TCmdPItem);
 		}
-		v2 += 22;
-		--v4;
-	} while (v4);
-	return v3;
+		src++;
+	}
+
+	return dst;
 }
 
-void *__fastcall DeltaExportObject(void *dst, void *src)
+BYTE *__fastcall DeltaExportObject(BYTE *dst, DObjectStr *src)
 {
-	char *v2; // esi
-
-	v2 = (char *)dst;
-	memcpy(dst, src, 0x7Fu);
-	return v2 + 127;
+	memcpy(dst, src, sizeof(DObjectStr) * MAXOBJECTS);
+	return dst + sizeof(DObjectStr) * MAXOBJECTS;
 }
 
-void *__fastcall DeltaExportMonster(void *dst, void *src)
+BYTE *__fastcall DeltaExportMonster(BYTE *dst, DMonsterStr *src)
 {
-	_BYTE *v2;     // edi
-	_BYTE *v3;     // esi
-	signed int v4; // ebx
+	int i;
 
-	v2 = (unsigned char *)src;
-	v3 = (unsigned char *)dst;
-	v4 = MAXMONSTERS;
-	do {
-		if (*v2 == -1) {
-			*v3++ = -1;
+	for (i = 0; i < MAXMONSTERS; i++) {
+		if (*(BYTE *)src == 0xFF) {
+			*dst = 0xFF;
+			dst++;
 		} else {
-			memcpy(v3, v2, 9u);
-			v3 += 9;
+			memcpy(dst, src, sizeof(DMonsterStr));
+			dst += sizeof(DMonsterStr);
 		}
-		v2 += 9;
-		--v4;
-	} while (v4);
-	return v3;
+		src++;
+	}
+
+	return dst;
 }
 
-void *__fastcall DeltaExportJunk(void *dst)
+BYTE *__fastcall DeltaExportJunk(BYTE *dst)
 {
-	char *v1;          // ebx
+	BYTE *v1;          // ebx
 	DJunk *v2;         // edi
 	MultiQuests *v3;   // esi
 	unsigned char *v4; // edi
 	int *v5;           // ebp
 
-	v1 = (char *)dst;
+	v1 = dst;
 	v2 = &sgJunk;
 	v3 = sgJunk.quests;
 	do {
@@ -325,24 +314,22 @@ void *__fastcall DeltaExportJunk(void *dst)
 	return v1;
 }
 
-int __fastcall msg_comp_level(char *begin, void *end)
+int __fastcall msg_comp_level(BYTE *buffer, BYTE *end)
 {
-	char *v2; // esi
-	int v3;   // edi
-	int v4;   // eax
+	int size, pkSize;
+
+	size = end - buffer - 1;
+	pkSize = PkwareCompress(buffer + 1, size);
+	*buffer = size != pkSize;
 
-	v2 = begin;
-	v3 = (char *)end - begin - 1;
-	v4 = PkwareCompress(begin + 1, v3);
-	*v2 = v3 != v4;
-	return v4 + 1;
+	return pkSize + 1;
 }
 
 void __cdecl delta_init()
 {
 	sgbDeltaChanged = 0;
-	memset(&sgJunk, 255, sizeof(sgJunk));
-	memset(sgLevels, 255, sizeof(sgLevels));
+	memset(&sgJunk, 0xFF, sizeof(sgJunk));
+	memset(sgLevels, 0xFF, sizeof(sgLevels));
 	memset(sgLocals, 0, sizeof(sgLocals));
 	deltaload = 0;
 }
@@ -448,12 +435,12 @@ void __fastcall delta_leave_sync(BYTE bLevel)
 
 BOOL __fastcall delta_portal_inited(int i)
 {
-	return sgJunk.portal[i].x == -1;
+	return sgJunk.portal[i].x == 0xFF;
 }
 
 BOOL __fastcall delta_quest_inited(int i)
 {
-	return sgJunk.quests[i].qstate != -1;
+	return sgJunk.quests[i].qstate != 0xFF;
 }
 
 void __fastcall DeltaAddItem(int ii)
@@ -590,7 +577,7 @@ void __cdecl DeltaLoadLevel()
 				v40 = 0;
 				v1 = &monster[0]._mfuty;
 				do {
-					if (sgLevels[currlevel].monster[v40]._mx != -1) {
+					if (sgLevels[currlevel].monster[v40]._mx != 0xFF) {
 						M_ClearSquares(v0);
 						v2 = v40 * 9 + 4721 * currlevel;
 						v3 = *((unsigned char *)&sgLevels[0].monster[0]._mx + v2);
@@ -644,7 +631,7 @@ void __cdecl DeltaLoadLevel()
 		do {
 			v9 = v8 + 4721 * currlevel;
 			v10 = *(&sgLevels[0].item[0].bCmd + v9);
-			if (v10 != -1) {
+			if (v10 != 0xFF) {
 				if (v10 == 1) {
 					v11 = FindGetItem(
 					    *(unsigned short *)((char *)&sgLevels[0].item[0].wIndx + v9),
@@ -1126,7 +1113,7 @@ void __fastcall NetSendCmdString(int pmask, const char *pszStr)
 
 void __fastcall RemovePlrPortal(int pnum)
 {
-	memset(&sgJunk.portal[pnum], 255, sizeof(sgJunk.portal[pnum]));
+	memset(&sgJunk.portal[pnum], 0xFF, sizeof(sgJunk.portal[pnum]));
 	sgbDeltaChanged = 1;
 }
 // 67618C: using guessed type char sgbDeltaChanged;
@@ -1354,86 +1341,73 @@ LABEL_16:
 
 void __fastcall DeltaImportData(BYTE cmd, DWORD recv_offset)
 {
-	unsigned char v2; // bl
-	int v3;           // esi
-	void *v4;         // eax
-	void *v5;         // eax
+	BYTE i;
+	BYTE *src;
 
-	v2 = cmd;
 	if (sgRecvBuf[0])
 		PkwareDecompress(&sgRecvBuf[1], recv_offset, 4721);
-	if (v2 == CMD_DLEVEL_JUNK) {
-		DeltaImportJunk(&sgRecvBuf[1]);
-	} else if (v2 < CMD_DLEVEL_0 || v2 > CMD_DLEVEL_16) {
-		TermMsg("msg:1");
+
+	src = &sgRecvBuf[1];
+	if (cmd == CMD_DLEVEL_JUNK) {
+		DeltaImportJunk(src);
+	} else if (cmd >= CMD_DLEVEL_0 && cmd <= CMD_DLEVEL_16) {
+		i = cmd - CMD_DLEVEL_0;
+		src = DeltaImportItem(src, sgLevels[i].item);
+		src = DeltaImportObject(src, sgLevels[i].object);
+		DeltaImportMonster(src, sgLevels[i].monster);
 	} else {
-		v3 = (unsigned char)(v2 - CMD_DLEVEL_0);
-		v4 = DeltaImportItem(&sgRecvBuf[1], &sgLevels[v3]);
-		v5 = DeltaImportObject(v4, sgLevels[v3].object);
-		DeltaImportMonster(v5, sgLevels[v3].monster);
+		TermMsg("msg:1");
 	}
-	++sgbDeltaChunks;
+
+	sgbDeltaChunks++;
 	sgbDeltaChanged = 1;
 }
 // 67618C: using guessed type char sgbDeltaChanged;
 // 67618D: using guessed type char sgbDeltaChunks;
 
-void *__fastcall DeltaImportItem(void *src, void *dst)
+BYTE *__fastcall DeltaImportItem(BYTE *src, TCmdPItem *dst)
 {
-	char *v2;      // edi
-	_BYTE *v3;     // esi
-	signed int v4; // ebx
+	int i;
 
-	v2 = (char *)dst;
-	v3 = (unsigned char *)src;
-	v4 = 127;
-	do {
-		if (*v3 == -1) {
-			memset(v2, 255, 0x16u);
-			++v3;
+	for (i = 0; i < MAXITEMS; i++) {
+		if (*src == 0xFF) {
+			memset(dst, 0xFF, sizeof(TCmdPItem));
+			src++;
 		} else {
-			memcpy(v2, v3, 0x16u);
-			v3 += 22;
+			memcpy(dst, src, sizeof(TCmdPItem));
+			src += sizeof(TCmdPItem);
 		}
-		v2 += 22;
-		--v4;
-	} while (v4);
-	return v3;
+		dst++;
+	}
+
+	return src;
 }
 
-void *__fastcall DeltaImportObject(void *src, void *dst)
+BYTE *__fastcall DeltaImportObject(BYTE *src, DObjectStr *dst)
 {
-	char *v2; // esi
-
-	v2 = (char *)src;
-	memcpy(dst, src, 0x7Fu);
-	return v2 + 127;
+	memcpy(dst, src, sizeof(DObjectStr) * MAXOBJECTS);
+	return src + sizeof(DObjectStr) * MAXOBJECTS;
 }
 
-void *__fastcall DeltaImportMonster(void *src, void *dst)
+BYTE *__fastcall DeltaImportMonster(BYTE *src, DMonsterStr *dst)
 {
-	char *v2;      // edi
-	_BYTE *v3;     // esi
-	signed int v4; // ebx
+	int i;
 
-	v2 = (char *)dst;
-	v3 = (unsigned char *)src;
-	v4 = MAXMONSTERS;
-	do {
-		if (*v3 == -1) {
-			memset(v2, 255, 9u);
-			++v3;
+	for (i = 0; i < MAXMONSTERS; i++) {
+		if (*src == 0xFF) {
+			memset(dst, 0xFF, sizeof(DMonsterStr));
+			src++;
 		} else {
-			memcpy(v2, v3, 9u);
-			v3 += 9;
+			memcpy(dst, src, sizeof(DMonsterStr));
+			src += sizeof(DMonsterStr);
 		}
-		v2 += 9;
-		--v4;
-	} while (v4);
-	return v3;
+		dst++;
+	}
+
+	return src;
 }
 
-void __fastcall DeltaImportJunk(void *src)
+void __fastcall DeltaImportJunk(BYTE *src)
 {
 	_BYTE *v1;         // ebx
 	int v2;            // edi
diff --git a/Source/msg.h b/Source/msg.h
index ebd603ecc..299810f4c 100644
--- a/Source/msg.h
+++ b/Source/msg.h
@@ -15,11 +15,11 @@ int __cdecl msg_wait_for_turns();
 void __cdecl msg_process_net_packets();
 void __cdecl msg_pre_packet();
 void __fastcall DeltaExportData(int pnum);
-void *__fastcall DeltaExportItem(void *dst, void *src);
-void *__fastcall DeltaExportObject(void *dst, void *src);
-void *__fastcall DeltaExportMonster(void *dst, void *src);
-void *__fastcall DeltaExportJunk(void *dst);
-int __fastcall msg_comp_level(char *begin, void *end);
+BYTE *__fastcall DeltaExportItem(BYTE *dst, TCmdPItem *src);
+BYTE *__fastcall DeltaExportObject(BYTE *dst, DObjectStr *src);
+BYTE *__fastcall DeltaExportMonster(BYTE *dst, DMonsterStr *src);
+BYTE *__fastcall DeltaExportJunk(BYTE *dst);
+int __fastcall msg_comp_level(BYTE *buffer, BYTE *end);
 void __cdecl delta_init();
 void __fastcall delta_kill_monster(int mi, BYTE x, BYTE y, BYTE bLevel);
 void __fastcall delta_monster_hp(int mi, int hp, BYTE bLevel);
@@ -55,10 +55,10 @@ void __fastcall RemovePlrPortal(int pnum);
 int __fastcall ParseCmd(int pnum, TCmd *pCmd);
 int __fastcall On_DLEVEL(int pnum, TCmdPlrInfoHdr *pCmd);
 void __fastcall DeltaImportData(BYTE cmd, DWORD recv_offset);
-void *__fastcall DeltaImportItem(void *src, void *dst);
-void *__fastcall DeltaImportObject(void *src, void *dst);
-void *__fastcall DeltaImportMonster(void *src, void *dst);
-void __fastcall DeltaImportJunk(void *src);
+BYTE *__fastcall DeltaImportItem(BYTE *src, TCmdPItem *dst);
+BYTE *__fastcall DeltaImportObject(BYTE *src, DObjectStr *dst);
+BYTE *__fastcall DeltaImportMonster(BYTE *src, DMonsterStr *dst);
+void __fastcall DeltaImportJunk(BYTE *src);
 int __fastcall On_SYNCDATA(void *packet, int pnum);
 int __fastcall On_WALKXY(TCmdLoc *pCmd, int pnum);
 int __fastcall On_ADDSTR(TCmdParam1 *pCmd, int pnum);
diff --git a/structs.h b/structs.h
index 0a49c55b9..b6f27d48a 100644
--- a/structs.h
+++ b/structs.h
@@ -696,24 +696,24 @@ typedef struct PortalStruct {
 
 #pragma pack(push, 1)
 typedef struct TCmd {
-	char bCmd;
+	BYTE bCmd;
 } TCmd;
 
 typedef struct TCmdLoc {
-	char bCmd;
+	BYTE bCmd;
 	BYTE x;
 	BYTE y;
 } TCmdLoc;
 
 typedef struct TCmdLocParam1 {
-	char bCmd;
+	BYTE bCmd;
 	BYTE x;
 	BYTE y;
 	WORD wParam1;
 } TCmdLocParam1;
 
 typedef struct TCmdLocParam2 {
-	char bCmd;
+	BYTE bCmd;
 	BYTE x;
 	BYTE y;
 	WORD wParam1;
@@ -721,7 +721,7 @@ typedef struct TCmdLocParam2 {
 } TCmdLocParam2;
 
 typedef struct TCmdLocParam3 {
-	char bCmd;
+	BYTE bCmd;
 	BYTE x;
 	BYTE y;
 	WORD wParam1;
@@ -730,25 +730,25 @@ typedef struct TCmdLocParam3 {
 } TCmdLocParam3;
 
 typedef struct TCmdParam1 {
-	char bCmd;
+	BYTE bCmd;
 	WORD wParam1;
 } TCmdParam1;
 
 typedef struct TCmdParam2 {
-	char bCmd;
+	BYTE bCmd;
 	WORD wParam1;
 	WORD wParam2;
 } TCmdParam2;
 
 typedef struct TCmdParam3 {
-	char bCmd;
+	BYTE bCmd;
 	WORD wParam1;
 	WORD wParam2;
 	WORD wParam3;
 } TCmdParam3;
 
 typedef struct TCmdGolem {
-	char bCmd;
+	BYTE bCmd;
 	BYTE _mx;
 	BYTE _my;
 	BYTE _mdir;
@@ -758,7 +758,7 @@ typedef struct TCmdGolem {
 } TCmdGolem;
 
 typedef struct TCmdQuest {
-	char bCmd;
+	BYTE bCmd;
 	BYTE q;
 	BYTE qstate;
 	BYTE qlog;
@@ -766,7 +766,7 @@ typedef struct TCmdQuest {
 } TCmdQuest;
 
 typedef struct TCmdGItem {
-	char bCmd;
+	BYTE bCmd;
 	BYTE bMaster;
 	BYTE bPnum;
 	BYTE bCursitem;
@@ -787,7 +787,7 @@ typedef struct TCmdGItem {
 } TCmdGItem;
 
 typedef struct TCmdPItem {
-	char bCmd;
+	BYTE bCmd;
 	BYTE x;
 	BYTE y;
 	WORD wIndx;
@@ -803,7 +803,7 @@ typedef struct TCmdPItem {
 } TCmdPItem;
 
 typedef struct TCmdChItem {
-	char bCmd;
+	BYTE bCmd;
 	BYTE bLoc;
 	WORD wIndx;
 	WORD wCI;
@@ -812,40 +812,40 @@ typedef struct TCmdChItem {
 } TCmdChItem;
 
 typedef struct TCmdDelItem {
-	char bCmd;
+	BYTE bCmd;
 	BYTE bLoc;
 } TCmdDelItem;
 
 typedef struct TCmdDamage {
-	char bCmd;
+	BYTE bCmd;
 	BYTE bPlr;
 	DWORD dwDam;
 } TCmdDamage;
 
 typedef struct TCmdPlrInfoHdr {
-	char bCmd;
+	BYTE bCmd;
 	WORD wOffset;
 	WORD wBytes;
 } TCmdPlrInfoHdr;
 
 typedef struct TCmdString {
-	char bCmd;
+	BYTE bCmd;
 	char str[MAX_SEND_STR_LEN];
 } TCmdString;
 
 typedef struct TFakeCmdPlr {
-	char bCmd;
+	BYTE bCmd;
 	BYTE bPlr;
 } TFakeCmdPlr;
 
 typedef struct TFakeDropPlr {
-	char bCmd;
+	BYTE bCmd;
 	BYTE bPlr;
 	DWORD dwReason;
 } TFakeDropPlr;
 
 typedef struct TSyncHeader {
-	char bCmd;
+	BYTE bCmd;
 	BYTE bLevel;
 	WORD wLen;
 	BYTE bObjId;
@@ -907,7 +907,7 @@ typedef struct DMonsterStr {
 } DMonsterStr;
 
 typedef struct DObjectStr {
-	char bCmd;
+	BYTE bCmd;
 } DObjectStr;
 
 typedef struct DLevel {
@@ -921,8 +921,8 @@ typedef struct LocalLevel {
 } LocalLevel;
 
 typedef struct DPortal {
-	char x;
-	char y;
+	BYTE x;
+	BYTE y;
 	BYTE level;
 	BYTE ltype;
 	BYTE setlvl;
@@ -962,7 +962,7 @@ typedef struct QuestStruct {
 	unsigned char _qmsg;
 	unsigned char _qvar1;
 	unsigned char _qvar2;
-	int _qlog; /* char */
+	int _qlog;
 } QuestStruct;
 
 typedef struct QuestData {