diff --git a/hostname.c b/hostname.c
index 91bc278..22f0fc4 100644
--- a/hostname.c
+++ b/hostname.c
@@ -7,7 +7,14 @@
 Boolean DoLookupName(Session *sess) {
     dnrBuffer dnrInfo;
 
-    TCPIPDNRNameToIP(sess->domainName, &dnrInfo);
+    if (TCPIPValidateIPString(sess->hostName)) {
+        cvtRec cvtInfo;
+        TCPIPConvertIPToHex(&cvtInfo, sess->hostName);
+        sess->ipAddr = cvtInfo.cvtIPAddress;
+        return TRUE;
+    }
+
+    TCPIPDNRNameToIP(sess->hostName, &dnrInfo);
     if (toolerror())
         return FALSE;
 
@@ -22,6 +29,9 @@ Boolean DoLookupName(Session *sess) {
         sess->ipAddr = dnrInfo.DNRIPaddress;
         return TRUE;
     } else {
+        if (dnrInfo.DNRstatus == DNR_Pending) {
+            TCPIPCancelDNR(&dnrInfo);
+        }
         return FALSE;
     }
 }
diff --git a/http.c b/http.c
index e4470a6..165a4c7 100644
--- a/http.c
+++ b/http.c
@@ -7,14 +7,14 @@
 #include "session.h"
 #include "http.h"
 
-Boolean BuildHTTPRequest(Session *sess, char *resourceStr, char *hostStr) {
+Boolean BuildHTTPRequest(Session *sess, char *resourceStr) {
     int sizeNeeded = 0;
     int rangeOffset;
     int round = 0;
 
     do {
         sizeNeeded = snprintf(sess->httpRequest, sizeNeeded, 
-            "GET %s HTTP/1.1\r\n"
+            "GET /%s HTTP/1.1\r\n"
             "Host: %s\r\n"
             "User-Agent: GSRemoteDisk/0.1\r\n"
             "Accept-Encoding: identity\r\n"
@@ -23,7 +23,7 @@ Boolean BuildHTTPRequest(Session *sess, char *resourceStr, char *hostStr) {
             "Range: bytes=%n1234567890-1234567890\r\n"
             "\r\n",
             resourceStr,
-            hostStr,
+            sess->hostName+1,
             &rangeOffset);
 
         if (sizeNeeded <= 0) {
diff --git a/http.h b/http.h
index 25a949c..5a6af25 100644
--- a/http.h
+++ b/http.h
@@ -4,7 +4,7 @@
 #include <types.h>
 #include "session.h"
 
-Boolean BuildHTTPRequest(Session *sess, char *resourceStr, char *hostStr);
+Boolean BuildHTTPRequest(Session *sess, char *resourceStr);
 void UpdateRequestRange(Session *sess, unsigned long start, unsigned long end);
 
 #endif
\ No newline at end of file
diff --git a/main.c b/main.c
index 27a7b0d..00b63d7 100644
--- a/main.c
+++ b/main.c
@@ -5,8 +5,10 @@
 #include <locator.h>
 #include <misctool.h>
 #include <memory.h>
+#include <orca.h>
 #include "http.h"
 #include "session.h"
+#include "seturl.h"
 #include "hostname.h"
 
 #define buffTypePointer 0x0000      /* For TCPIPReadTCP() */
@@ -21,38 +23,48 @@ http://ia800505.us.archive.org/16/items/a2gs_System_1.0_1986_Apple_FW/System_1.0
 
 static char delimitStr[] = "\p\r\n\r\n";
 
-int main(void) {
+char *defaultURL = "http://ia800505.us.archive.org/16/items/a2gs_System_1.0_1986_Apple_FW/System_1.0_1986_Apple_FW.2mg";
+
+
+int main(int argc, char **argv) {
     TLStartUp();
     
     LoadOneTool(54,0x200);
     TCPIPStartUp();
     
-    TCPIPConnect(NULL);
+    if (TCPIPGetConnectStatus() == FALSE) {
+        TCPIPConnect(NULL);
+        if (toolerror())
+            goto exit;
+    }
 
-    Session sess;
-    FILE *f = fopen("out", "wb");
+    Session sess = {0};
+
+    char *url = (argc > 1) ? argv[1] : defaultURL;
     
-    BuildHTTPRequest(&sess, "/16/items/a2gs_System_1.0_1986_Apple_FW/System_1.0_1986_Apple_FW.2mg", "ia800505.us.archive.org");
-    fputs(sess.httpRequest, f);
-    
-    UpdateRequestRange(&sess, 0, 511);
-    fputs(sess.httpRequest, f);
-    
-    strcpy(sess.domainName, "\pia800505.us.archive.org");
-    Boolean result = DoLookupName(&sess);
-    
-    if (result) {
-        printf("IP = %lu.%lu.%lu.%lu\n",
-               sess.ipAddr & 0xFF,
-               (sess.ipAddr >> 8)  & 0xFF,
-               (sess.ipAddr >> 16) & 0xFF,
-               (sess.ipAddr >> 24));
-    } else {
-        printf("Address lookup failed\n");
+    enum SetURLResult result = SetURL(&sess, url, TRUE, FALSE);
+
+    if (result != SETURL_SUCCESSFUL) {
+        printf("SetURL error %i\n", (int)result);
         goto exit;
     }
     
-    sess.port = 80;
+    unsigned long startByte = 0;
+    if (argc > 2) {
+        startByte = strtoul(argv[2], NULL, 0);
+    }
+    UpdateRequestRange(&sess, startByte, startByte + 511);
+
+    printf("Request:\n");
+    printf("=========\n");
+    int i;
+    for (i = 0; sess.httpRequest[i] != '\0'; i++) {
+        char ch = sess.httpRequest[i];
+        if (ch != '\r')
+            putchar(ch);
+    }
+    printf("=========\n");
+    printf("\n", i);
     
     int err;
     if ((err = StartTCPConnection(&sess)) != 0) {
@@ -61,18 +73,20 @@ int main(void) {
     }
     
     TCPIPWriteTCP(sess.ipid, sess.httpRequest, strlen(sess.httpRequest), TRUE, FALSE);
-    
-    LongWord startTime = GetTick();
-    
-    while (GetTick() - startTime < 3*60) {
-        //printf("polling\n");
-        TCPIPPoll();
-    }
 
-    rlrBuff rlrBuff;
-    TCPIPReadLineTCP(sess.ipid, (void*)((LongWord)delimitStr | 0x80000000),
-                     buffTypeNewHandle, (Ref)NULL,
-                     0xFFFFFF, &rlrBuff);
+    rlrBuff rlrBuff = {0};
+    Word tcpError;
+    do {
+        TCPIPPoll();
+        tcpError = TCPIPReadLineTCP(sess.ipid,
+                (void*)((LongWord)delimitStr | 0x80000000),
+                buffTypeNewHandle, (Ref)NULL,
+                0xFFFFFF, &rlrBuff);
+        if (tcpError || toolerror()) {
+            printf("tcpError = %u, toolerror = %u\n", tcpError, toolerror());
+            break;
+        }
+    } while (rlrBuff.rlrBuffCount == 0);
 
     printf("Response:\n");
     printf("=========\n");
@@ -81,11 +95,8 @@ int main(void) {
         if (ch != '\r')
             putchar(ch);
     }
-    //printf("%s\n", *(rlrBuff.rlrBuffHandle));
     printf("=========\n");
-    
-    printf("Response headers handle size = %lu \n", GetHandleSize(rlrBuff.rlrBuffHandle));
-    printf("Reported response size       = %lu \n", rlrBuff.rlrBuffCount);
+    printf("Response size = %lu\n", rlrBuff.rlrBuffCount);
     
     EndTCPConnection(&sess);
 
diff --git a/session.h b/session.h
index 8787697..c219352 100644
--- a/session.h
+++ b/session.h
@@ -25,8 +25,8 @@ typedef struct Session {
     LongWord ipAddr;
     Word port;
 
-    /* Domain name of host (p-string; empty string for host specified by IP) */
-    char domainName[256];
+    /* Domain name or IP address of host (p-string, but also null-terminated) */
+    char hostName[257];
     /* Time (GetTick) of last DNS lookup */
     LongWord dnsTime;
 } Session;
diff --git a/seturl.c b/seturl.c
new file mode 100644
index 0000000..62aff0c
--- /dev/null
+++ b/seturl.c
@@ -0,0 +1,95 @@
+#include <types.h>
+#include <errno.h>
+#include "session.h"
+#include "urlparser.h"
+#include "strcasecmp.h"
+#include "hostname.h"
+#include "http.h"
+#include "tcpconnection.h"
+#include "seturl.h"
+
+#define DEFAULT_HTTP_PORT 80
+
+/* Limit to make sure sizes stay within the range of 16-bit values */
+#define MAX_URL_LENGTH 30000
+
+
+enum SetURLResult
+SetURL(Session *sess, char *url, Boolean permissive, Boolean partialOK) {
+    if (strlen(url) > MAX_URL_LENGTH) {
+        return URL_TOO_LONG;
+    }
+    
+    for(unsigned int i = 0; url[i] != '\0'; i++) {
+        if (url[i] <= ' ' && url[i] >= 0) {
+            return INVALID_CHARACTER_IN_URL;
+        }
+    }
+
+    URLParts urlParts = ParseURL(url);
+
+    if (urlParts.errorFound)
+        return BAD_URL_SYNTAX;
+
+    if (urlParts.scheme == NULL) {
+        if (permissive) {
+            urlParts.scheme = "http";
+        } else {
+            return BAD_URL_SYNTAX;
+        }
+    } else if (strcasecmp(urlParts.scheme, "http") != 0) {
+        return UNSUPPORTED_URL_SCHEME;
+    }
+    
+    if (urlParts.username != NULL || urlParts.password != NULL) {
+        return AUTHENTICATION_NOT_SUPPORTED;
+    }
+    
+    if (urlParts.fragment != NULL) {
+        return FRAGMENT_NOT_SUPPORTED;
+    }
+    
+    unsigned long portNum;
+    char *endPtr;
+    if (urlParts.port == NULL || *urlParts.port == '\0') {
+        portNum = DEFAULT_HTTP_PORT;
+    } else {
+        errno = 0;
+        portNum = strtoul(urlParts.port, &endPtr, 10);
+        if (errno || *endPtr != '\0' || portNum > 0xFFFF) {
+            return INVALID_PORT_NUMBER;
+        }
+    }
+    sess->port = portNum;
+
+    if (urlParts.host == NULL) {
+        if (!partialOK || sess->hostName[0] == 0) {
+            return NO_HOST_SPECIFIED;
+        }
+    } else if (*urlParts.host == '\0') {
+        return NO_HOST_SPECIFIED;
+    } else if (*urlParts.host == '[') {
+        return IPV6_NOT_SUPPORTED;
+    } else {
+        size_t len;
+        if ((len = strlen(urlParts.host)) > 255) {
+            return HOSTNAME_TOO_LONG;
+        }
+        
+        strcpy(&sess->hostName[1], urlParts.host);
+        sess->hostName[0] = len;
+        
+        if (!DoLookupName(sess)) {
+            return NAME_LOOKUP_FAILED;
+        }
+    }
+
+    if (!BuildHTTPRequest(sess, urlParts.path)) {
+        return OUT_OF_MEMORY;
+    }
+    
+    /* End any existing TCP connection to old URL */
+    EndTCPConnection(sess);
+    
+    return SETURL_SUCCESSFUL;
+}
diff --git a/seturl.h b/seturl.h
new file mode 100644
index 0000000..652428e
--- /dev/null
+++ b/seturl.h
@@ -0,0 +1,23 @@
+#ifndef SETURL_H
+#define SETURL_H
+
+enum SetURLResult {
+    SETURL_SUCCESSFUL = 0,
+    URL_TOO_LONG,
+    INVALID_CHARACTER_IN_URL,
+    BAD_URL_SYNTAX,
+    UNSUPPORTED_URL_SCHEME,
+    AUTHENTICATION_NOT_SUPPORTED,
+    FRAGMENT_NOT_SUPPORTED,
+    INVALID_PORT_NUMBER,
+    NO_HOST_SPECIFIED,
+    IPV6_NOT_SUPPORTED,
+    HOSTNAME_TOO_LONG,
+    NAME_LOOKUP_FAILED,
+    OUT_OF_MEMORY
+};
+
+enum SetURLResult
+SetURL(Session *sess, char *url, Boolean permissive, Boolean partialOK);
+
+#endif
diff --git a/strncasecmp.c b/strcasecmp.c
similarity index 51%
rename from strncasecmp.c
rename to strcasecmp.c
index 8318ad3..821bbfd 100644
--- a/strncasecmp.c
+++ b/strcasecmp.c
@@ -5,12 +5,23 @@
 #include <stddef.h>
 #include <ctype.h>
 
+int strcasecmp(const char *s1, const char *s2)
+{
+    while (*s1 != '\0' && tolower(*s1) == tolower(*s2)) {
+        s1++;
+        s2++;
+    }
+    
+    return (int)*s1 - (int)*s2;
+}
+
+
 int strncasecmp(const char *s1, const char *s2, size_t n)
 {
     if (n == 0)
         return 0;
 
-    while (n > 1 && *s1 != 0 && tolower(*s1) == tolower(*s2)) {
+    while (n > 1 && *s1 != '\0' && tolower(*s1) == tolower(*s2)) {
         s1++;
         s2++;
         n--;
diff --git a/strcasecmp.h b/strcasecmp.h
new file mode 100644
index 0000000..81eee39
--- /dev/null
+++ b/strcasecmp.h
@@ -0,0 +1,9 @@
+#ifndef STRCASECMP_H
+#define STRCASECMP_H
+
+#include <stddef.h>
+
+int strcasecmp(const char *s1, const char *s2);
+int strncasecmp(const char *s1, const char *s2, size_t n);
+
+#endif
diff --git a/strncasecmp.h b/strncasecmp.h
deleted file mode 100644
index ae20a64..0000000
--- a/strncasecmp.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef STRNCASECMP_H
-#define STRNCASECMP_H
-
-int strncasecmp(const char *s1, const char *s2, size_t n);
-
-#endif
diff --git a/tcpconnection.c b/tcpconnection.c
index 5a50362..80150e6 100644
--- a/tcpconnection.c
+++ b/tcpconnection.c
@@ -20,11 +20,8 @@ Word StartTCPConnection(Session *sess) {
     srBuff mySRBuff;
     LongWord initialTime;
     
-    if (TCPIPGetConnectStatus() == FALSE) {
-        TCPIPConnect(NULL);
-        if (toolerror())
-            return aspNetworkErr;
-    }
+    /* End any existing TCP connection */
+    EndTCPConnection(sess);
     
     sess->ipid = 
         TCPIPLogin(userid(), sess->ipAddr, sess->port, 0, 0x40);
diff --git a/urlparser.c b/urlparser.c
new file mode 100644
index 0000000..7482682
--- /dev/null
+++ b/urlparser.c
@@ -0,0 +1,122 @@
+#include "urlparser.h"
+#include <string.h>
+
+/*
+ * Parse the URL and break it up into its component parts.
+ *
+ * This handles http URLs and other schemes with the same syntax.
+ *
+ * It can also handle relative URLs containing an absolute-path reference
+ * (i.e. starting with /) and URL-like addresses without the scheme prefix.
+ * In these cases, the portions of the URL not provided will be NULL.
+ *
+ * This modifies the original string passed in, breaking it up into components.
+ */
+URLParts ParseURL(char *url) {
+    char *sep, sep2;
+    URLParts urlParts = {0};
+
+    sep = strrchr(url, '#');
+    if (sep) {
+        *sep = '\0';
+        urlParts.fragment = sep + 1;
+    }
+
+    /* Detect relative URL (absolute-path reference only) */
+    if (url[0] == '/') {
+        if (url[1] != '/') {
+            url++;
+            goto pathPart;
+        } else {
+            urlParts.errorFound = 1;
+            return urlParts;
+        }
+    }
+    
+    sep = strchr(url, ':');
+    if (sep) {
+        urlParts.scheme = url;
+        *sep = '\0';
+        url = sep + 1;
+    }
+    
+    if (urlParts.scheme != NULL) {
+        if (strncmp(url, "//", 2) == 0) {
+            url += 2;
+        } else {
+            urlParts.errorFound = 1;
+            return urlParts;
+        }
+    }
+    
+    urlParts.path = strchr(url, '/');
+    if (urlParts.path == NULL) {
+        urlParts.path = "";
+    } else {
+        *urlParts.path = '\0';
+        urlParts.path++;
+    }
+    
+    sep = strchr(url, '@');
+    if (sep) {
+        *sep = '\0';
+        urlParts.username = url;
+        
+        urlParts.password = strchr(url, ':');
+        if (urlParts.password != NULL) {
+            *urlParts.password = '\0';
+            urlParts.password++;
+        }
+        
+        url = sep + 1;
+    }
+    
+    urlParts.host = url;
+    
+    /* Handle IPv6 address syntax */
+    if (*url == '[') {
+        sep = strchr(url, ']');
+        if (sep) {
+            url = sep + 1;
+        } else {
+            urlParts.errorFound = 1;
+            return urlParts;
+        }
+    }
+    
+    sep = strchr(url, ':');
+    if (sep) {
+        *sep = '\0';
+        urlParts.port = sep + 1;
+    }
+
+pathPart:
+    return urlParts;
+}
+
+
+#ifdef URLPARSER_TEST
+#include <stdio.h>
+
+int main(int argc, char **argv)
+{
+    URLParts urlParts;
+
+    if (argc < 2)
+        return 1;
+    
+    urlParts = ParseURL(argv[1]);
+    
+    printf("scheme:   %s\n", urlParts.scheme ? urlParts.scheme : "(NULL)");
+    printf("username: %s\n", urlParts.username ? urlParts.username : "(NULL)");
+    printf("password: %s\n", urlParts.password ? urlParts.password : "(NULL)");
+    printf("host:     %s\n", urlParts.host ? urlParts.host : "(NULL)");
+    printf("port:     %s\n", urlParts.port ? urlParts.port : "(NULL)");
+    printf("path:     %s\n", urlParts.path ? urlParts.path : "(NULL)");
+    printf("fragment: %s\n", urlParts.fragment ? urlParts.fragment : "(NULL)");
+    
+    if (urlParts.errorFound) {
+        printf("Error found\n");
+    }
+}
+#endif
diff --git a/urlparser.h b/urlparser.h
new file mode 100644
index 0000000..091cc71
--- /dev/null
+++ b/urlparser.h
@@ -0,0 +1,25 @@
+#ifndef URLPARSER_H
+#define URLPARSER_H
+
+#ifdef __ORCAC__
+# include <types.h>
+#else
+typedef _Bool Boolean;
+#endif
+
+typedef struct URLParts {
+    char *scheme;
+    char *username;
+    char *password;
+    char *host;
+    char *port;
+    char *path; /* Omits leading '/'.  Includes query, if any. */
+    char *fragment;
+    
+    Boolean errorFound;
+} URLParts;
+
+
+URLParts ParseURL(char *url);
+
+#endif