diff --git a/.gitignore b/.gitignore
index a826c87..e8fde75 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 *.o
 xrxs
+realms/
diff --git a/aux.h b/aux.h
index d926712..b492f9f 100644
--- a/aux.h
+++ b/aux.h
@@ -1,4 +1,14 @@
-typedef enum { CTL = 1, USERS, CARTS, SLOT, DATA, REALMS, UNIVERSE } FileType;
+typedef enum {
+  CTL = 1,
+  USERS,
+  CARTS,
+  SLOT,
+  SPRITE_DATA,
+  AUDIO_DATA,
+  TEXT_DATA,
+  REALMS,
+  UNIVERSE
+} FileType;
 
 typedef struct Aux {
   FileType type;
diff --git a/realm.c b/realm.c
index 38678fe..d079c9d 100644
--- a/realm.c
+++ b/realm.c
@@ -35,10 +35,14 @@ Realm* parse_realm(char* name) {
 
   scat(file, "/realm");
   f = fopen(file, "r");
-  if (fgets(buf, 256, f)) {
-    self = malloc(sizeof(Realm));
-    sscanf(buf, "%hu %llu", &(self->max), &(self->password));
-    fclose(f);
+  if (f != nil) {
+    if (fgets(buf, 256, f)) {
+      self = malloc(sizeof(Realm));
+      sscanf(buf, "%hu %llu", &(self->max), &(self->password));
+      fclose(f);
+    } else {
+      return nil;
+    }
   } else {
     return nil;
   }
@@ -58,6 +62,32 @@ Realm* find_realm(UserInfo* table, char* name) {
       return u->realm;
     u++;
   }
+  return nil;
 }
 
-void save_realm(Realm* self) {}
\ No newline at end of file
+void save_realm(Realm* self) {
+  FILE* f;
+  char path[64];
+  char file[64];
+  scat(path, "realms/");
+  scat(path, self->name);
+  scpy(path, file, 64);
+
+  scat(file, "/realm");
+  f = fopen(file, "w");
+  if (f != nil) {
+    fprintf(f, "%hu %llu", self->max, self->password);
+    fclose(f);
+    save_universe(self->universe, self->name);
+  }
+}
+
+void destroy_realm(Realm* self) {
+  if (self != nil) {
+    if (self->universe != nil) {
+      destroy_universe(self->universe);
+    }
+    free(self);
+    self = nil;
+  }
+}
\ No newline at end of file
diff --git a/user.c b/user.c
index e69de29..616bcc0 100644
--- a/user.c
+++ b/user.c
@@ -0,0 +1,100 @@
+#include <u.h>
+#include <libc.h>
+#include "util.h"
+#include "cart.h"
+#include "realm.h"
+#include "user.h"
+
+extern UserInfo users_table[64];
+
+UserInfo* find_user(UserInfo* table, char* uname) {
+  UserInfo* u = table;
+  int i;
+  for (i = 0; i < 64; i++) {
+    if (scmp(uname, u->name))
+      return u;
+    u++;
+  }
+  return nil;
+}
+
+int load_cart(UserInfo* table, char* uname, char* cart_name) {
+  Cart* c = find_cart(table, cart_name);
+  UserInfo* u = find_user(table, uname);
+
+  if (u == nil)
+    return 0;
+
+  if (c != nil) {
+    u->cart = c;
+    return 1;
+  } else {
+    u->cart = create_cart(cart_name);
+    if (u->cart == nil)
+      return 0;
+    else
+      return 1;
+  }
+}
+
+int enter_realm(UserInfo* table, char* uname, char* realm_name) {
+  Realm* r = find_realm(table, realm_name);
+  UserInfo* u = find_user(table, uname);
+  int i, j;
+
+  if (u == nil || u->cart == nil)
+    return 0;
+
+  for (i = j = 0; i < 64; i++) {
+    if (table[i].realm != nil && scmp(table[i].realm->name, realm_name))
+      j++;
+  }
+  if (j >= r->max)
+    return 0;
+
+  if (r != nil) {
+    u->realm = r;
+    return 1;
+  } else {
+    u->realm = parse_realm(realm_name);
+    if (u->realm == nil)
+      return 0;
+    else
+      return 1;
+  }
+}
+
+int leave_realm(UserInfo* table, char* uname) {
+  UserInfo* u = find_user(table, uname);
+  Realm* r;
+
+  if (u == nil)
+    return 0;
+
+  r = u->realm;
+  if (r == nil)
+    return 0;
+
+  save_realm(r);
+  u->realm = nil;
+  if (find_realm(table, r->name) == nil)
+    destroy_realm(r);
+  return 1;
+}
+
+int unload_cart(UserInfo* table, char* uname) {
+  UserInfo* u = find_user(table, uname);
+  Cart* c;
+
+  if (u == nil)
+    return 0;
+
+  c = u->cart;
+  if (c == nil)
+    return 0;
+
+  u->cart = nil;
+  if (find_cart(table, c->name) == nil)
+    destroy_cart(c);
+  return 1;
+}
\ No newline at end of file
diff --git a/user.h b/user.h
index 4b6a390..09c5cb3 100644
--- a/user.h
+++ b/user.h
@@ -7,7 +7,8 @@ typedef struct UserInfo {
   Realm* realm;
 } UserInfo;
 
-int load_cart(char* uname, char* cart_name);
-int enter_realm(char* uname, char* realm_name);
-int leave_realm(char* uname, Realm* realm);
-int unload_cart(char* uname, Cart* cart);
+UserInfo* find_user(UserInfo* table, char* uname);
+int load_cart(UserInfo* table, char* uname, char* cart_name);
+int enter_realm(UserInfo* table, char* uname, char* realm_name);
+int leave_realm(UserInfo* table, char* uname);
+int unload_cart(UserInfo* table, char* uname);
diff --git a/util.c b/util.c
index 5a9d080..c56a5c5 100644
--- a/util.c
+++ b/util.c
@@ -138,4 +138,49 @@ char* read_chars(char* path) {
     fclose(f);
     return buf;
   }
+}
+
+void strreverse(char* begin, char* end) {
+
+  char aux;
+
+  while (end > begin)
+
+    aux = *end, *end-- = *begin, *begin++ = aux;
+}
+
+void itoa(int value, char* str, int base) {
+
+  static char num[] = "0123456789abcdefghijklmnopqrstuvwxyz";
+
+  char* wstr = str;
+
+  int sign;
+
+  // Validate base
+
+  if (base < 2 || base > 35) {
+    *wstr = '\0';
+    return;
+  }
+
+  // Take care of sign
+
+  if ((sign = value) < 0)
+    value = -value;
+
+  // Conversion. Number is reversed.
+
+  do
+    *wstr++ = num[value % base];
+  while (value /= base);
+
+  if (sign < 0)
+    *wstr++ = '-';
+
+  *wstr = '\0';
+
+  // Reverse string
+
+  strreverse(str, wstr - 1);
 }
\ No newline at end of file
diff --git a/util.h b/util.h
index 349f31c..e36dd0b 100644
--- a/util.h
+++ b/util.h
@@ -14,4 +14,5 @@ char* scat(char* dst, const char* src);
 int ssin(char* str, char* substr);
 char* ccat(char* dst, char c);
 char* read_bytes(char* path);
-char* read_chars(char* path);
\ No newline at end of file
+char* read_chars(char* path);
+void itoa(int, char*, int);
\ No newline at end of file
diff --git a/xrxs.c b/xrxs.c
index 887f7f5..39fff16 100644
--- a/xrxs.c
+++ b/xrxs.c
@@ -6,6 +6,7 @@
 #include <stdio.h>
 #include <dirent.h>
 #include <libString.h>
+#include <string.h>
 #include "err.h"
 #include "command.h"
 #include "util.h"
@@ -15,6 +16,9 @@
 #include "realm.h"
 #include "user.h"
 
+#define CARTSPATH "./carts"
+#define REALMSPATH "./realms"
+
 int chatty9p = 1;
 
 static Tree* tree;
@@ -67,95 +71,29 @@ void login(char* uname, char* password) {
 
 int logout(char* uname) {
   int i;
-  fprintf(stderr, uname);
+  UserInfo* u = users_table;
+
   for (i = 0; i < 64; i++) {
-    if (scmp(uname, users_table[i].name)) {
-      *(users_table[i].name) = 0;
-      users_table[i].password = 0;
-      /* free cart */
-      /* free realm */
+    if (scmp(uname, u->name)) {
+      *(u->name) = 0;
+      u->password = 0;
+      if (u->realm != nil)
+        leave_realm(users_table, uname);
+      if (u->cart != nil)
+        unload_cart(users_table, uname);
       return 1;
     }
+    u++;
   }
   return 0;
 }
 
-int load(char* uname, char* cart) {
-  /* 1. get file handle to cartridge file
-   * 2. make cartridge file available in CART.data for this user
-   * 3. add cartridge name to user's UserInfo
-   * 4. if cartridge data dir is not empty, walk it
-   * 5. for each file in data dir, create corresponding
-   *    data file in DATA/ for this user, grab a file handle, and make
-   *    the data available in DATA.data
-   */
-  return 1;
-}
+void protect(char* uname, char* password) {
+  UserInfo* u = find_user(users_table, uname);
 
-int rcreate(char* realm) { // create is taken in the libc header!
-  /* 1. split input by space -- if 2+ elements, second element
-   *    is the max number of members (default 4)
-   * 2. check if realm exists; return 0 if it does
-   * 3. create real files in the realms directory and fill as
-   *    appropriate
-   */
-  return 1;
-}
-
-int protect(char* password) {
-  /* 1. if current realm has a password already, return 0;
-   * 2. otherwise, hash the password and put it after the
-   *    member limit in the realm file
-   */
-  return 1;
-}
-
-int enter(char* uname, char* realm) {
-  /* 1. get password for realm; if none, skip to 3
-   * 2. check password for current user against it;
-   *    return 0 if different
-   * 3. if member limit already met, return 0
-   * 4. otherwise, insert username in the realm
-   *    and the realm name in the user's UserInfo
-   */
-  return 1;
-}
-
-int leave(char* uname) {
-  /* 1. if not in a realm, return 0;
-   * 2. else remove self from realm file
-   *    and remove realm from user's UserInfo
-   */
-  return 1;
-}
-
-int save(char* uname) {
-  /* 1. flush this user's universe to the realm;
-   * maybe this is not needed
-   */
-  return 1;
-}
-
-int reset(char* uname) {
-  /* 1. save
-   * 2. leave
-   * 3. clear this user's password
-   * 4. the client should now be able to restart execution
-   *    of the cartridge safely
-   */
-  return 1;
-}
-
-int unload(char* uname) {
-  /* 1. reset
-   * 2. clear cartridge data from CART->data for this user
-   * 3. destroy all files in DATA/ for this user
-   * 4. remove cartridge from UserInfo for thi user
-   * 5. the client should now be able to unload
-   *    the cartridge from memory safely and restart
-   *    the 'firmware' ROM execution
-   */
-  return 1;
+  if (u != nil && u->realm != nil) {
+    u->realm->password = hash(password, 0);
+  }
 }
 
 void write_ctl(Req* r) {
@@ -166,6 +104,9 @@ void write_ctl(Req* r) {
   for (i = 0; i < r->ifcall.count && *c != ' ' && *c != '\n'; i++) {
     ccat(cmd, *c++);
   }
+  if (*c == ' ')
+    c++;
+
   fprintf(stderr, cmd);
   uvlong const cmd_hashv = hash(cmd, 0);
   switch (cmd_hashv) {
@@ -173,19 +114,19 @@ void write_ctl(Req* r) {
       login(r->fid->uid, c);
       break;
     case LOAD:
-      // load(r->fid->uid, c);
+      load_cart(users_table, r->fid->uid, c);
       break;
     case CREATE:
-      // rcreate(c);
+      create_realm(c);
       break;
     case PROTECT:
-      // protect(c);
+      protect(r->fid->uid, c);
       break;
     case ENTER:
-      // enter(r->fid->uid, c);
+      enter_realm(users_table, r->fid->uid, c);
       break;
     case LEAVE:
-      // leave(r->fid->uid);
+      leave_realm(users_table, r->fid->uid);
       break;
     case LOGOUT:
       logout(r->fid->uid);
@@ -197,7 +138,7 @@ void write_ctl(Req* r) {
       // reset(r->fid->uid);
       break;
     case UNLOAD:
-      // unload(r->fid->uid);
+      unload_cart(users_table, r->fid->uid);
       break;
   }
   r->ofcall.count = r->ifcall.count;
@@ -205,6 +146,39 @@ void write_ctl(Req* r) {
   respond(r, nil);
 }
 
+void write_universe(Req* r) {
+  char key[16] = {0};
+  char value[64] = {0};
+  char* c = r->ifcall.data;
+  UserInfo* u = find_user(users_table, r->fid->uid);
+  Atom* a;
+  int i;
+
+  for (i = 0; i < 15 && i < r->ifcall.count && *c != ' ' && *c != '\n'; i++) {
+    ccat(key, *c++);
+  }
+  c++;
+  for (i = 0; i < 63 && i < r->ifcall.count && *c != ' ' && *c != '\n'; i++) {
+    ccat(value, *c++);
+  }
+
+  if (u != nil && u->realm != nil && u->realm->universe != nil) {
+    a = get_atom(u->realm->universe, key);
+    if (a != nil) {
+      scpy(value, a->value, 64);
+    } else {
+      a = malloc(sizeof(Atom));
+      scpy(key, a->name, 16);
+      scpy(value, a->value, 64);
+      a->next = nil;
+      set_atom(u->realm->universe, a);
+    }
+  }
+  r->ofcall.count = r->ifcall.count;
+  r->fid->file->dir.length = r->ifcall.count;
+  respond(r, nil);
+}
+
 void xrxs_write(Req* r) {
   Aux* a = r->fid->file->aux;
   switch (a->type) {
@@ -212,7 +186,7 @@ void xrxs_write(Req* r) {
       write_ctl(r);
       break;
     case UNIVERSE:
-      // write_universe(r);
+      write_universe(r);
       break;
     default:
       respond(r, nil);
@@ -244,44 +218,7 @@ void read_users(Req* r) {
   respond(r, nil);
 }
 
-void xrxs_read(Req* r) {
-  Aux* a = r->fid->file->aux;
-  switch (a->type) {
-    case USERS:
-      read_users(r);
-      break;
-    case CARTS:
-      // read_carts(r);
-      break;
-    case SLOT:
-      // read_slot(r);
-      break;
-    case DATA:
-      // read_data(r);
-      break;
-    case REALMS:
-      // read_realms(r);
-      break;
-    case UNIVERSE:
-      // read_universe(r);
-      break;
-    default:
-      respond(r, nil);
-      break;
-  }
-}
-
-void fs_destroy_file(File* f) {
-  Aux* a = f->aux;
-  if (a && a->data) {
-    free(a->data);
-    free(a);
-  } else if (a) {
-    free(a);
-  }
-}
-
-String** listdir(char* path) {
+String** list_dir(char* path) {
   String** self = malloc(128 * sizeof(String*));
   DIR* dir;
   struct dirent* ent;
@@ -306,6 +243,131 @@ String** listdir(char* path) {
   return self;
 }
 
+void read_carts(Req* r) {
+  String** carts = list_dir(CARTSPATH);
+  String** c = carts;
+  char data[4096] = {0};
+  while (*c != nil) {
+    scat(data, (*c)->base);
+    ccat(data, '\n');
+    c++;
+  }
+  readstr(r, data);
+  respond(r, nil);
+}
+
+void read_slot(Req* r) {
+  UserInfo* u = find_user(users_table, r->fid->uid);
+  if (u == nil)
+    goto end;
+
+  if (u->cart == nil)
+    goto end;
+
+  readstr(r, u->cart->rom);
+end:
+  respond(r, nil);
+}
+
+void read_data(Req* r, FileType t) {
+  UserInfo* u = find_user(users_table, r->fid->uid);
+
+  if (u->cart == nil)
+    goto end;
+
+  switch (t) {
+    case SPRITE_DATA:
+      readstr(r, u->cart->sprite_data);
+      break;
+    case AUDIO_DATA:
+      readstr(r, u->cart->audio_data);
+      break;
+    case TEXT_DATA:
+      readstr(r, u->cart->txt_data);
+      break;
+  }
+end:
+  respond(r, nil);
+}
+
+void read_realms(Req* r) {
+  String** realms = list_dir(REALMSPATH);
+  String** rr = realms;
+  Realm* realm;
+  char data[4096] = {0};
+  int i, u, m, p;
+  char ubuf[8] = {0};
+  char mbuf[8] = {0};
+  char pbuf[2] = {0};
+
+  while (*rr != nil) {
+    scat(data, (*rr)->base);
+    ccat(data, ' ');
+
+    realm = parse_realm((*rr)->base);
+    m = realm->max;
+    p = realm->password ? 1 : 0;
+
+    for (i = u = 0; i < 64; i++) {
+      if (
+        users_table[i].realm != nil &&
+        scmp(users_table[i].realm->name, realm->name))
+        u++;
+    }
+    itoa(u, ubuf, 10);
+    scat(data, ubuf);
+    ccat(data, ' ');
+    itoa(m, mbuf, 10);
+    scat(data, mbuf);
+    ccat(data, ' ');
+    itoa(p, pbuf, 10);
+    scat(data, pbuf);
+    ccat(data, '\n');
+    rr++;
+  }
+  readstr(r, data);
+  respond(r, nil);
+}
+
+void xrxs_read(Req* r) {
+  Aux* a = r->fid->file->aux;
+  switch (a->type) {
+    case USERS:
+      read_users(r);
+      break;
+    case CARTS:
+      read_carts(r);
+      break;
+    case SLOT:
+      read_slot(r);
+      break;
+    case SPRITE_DATA:
+    case AUDIO_DATA:
+    case TEXT_DATA:
+      read_data(r, a->type);
+      break;
+    case REALMS:
+      read_realms(r);
+      break;
+    case UNIVERSE:
+      // read_universe(r);
+      break;
+    default:
+      respond(r, nil);
+      break;
+  }
+}
+
+void fs_destroy_file(File* f) {
+  Aux* a = f->aux;
+  if (a && a->data) {
+    free(a->data);
+    free(a);
+  } else if (a) {
+    free(a);
+  }
+}
+
 Srv fs = {.attach = xrxs_attach, .read = xrxs_read, .write = xrxs_write};
 
 int threadmaybackground(void) { return 1; }
@@ -314,7 +376,6 @@ void threadmain(int argc, char* argv[]) {
   char* mtpt = nil;
   char* usocket = nil;
   int i;
-  String** cart;
 
   /* if -h CMD is given, print the hash value of CMD */
   if (argc == 3 && scmp(argv[1], "-h")) {
@@ -348,16 +409,31 @@ void threadmain(int argc, char* argv[]) {
   closefile(createfile(tree->root, "users", nil, 0400, create_aux(USERS)));
   closefile(createfile(tree->root, "slot", nil, 0400, create_aux(SLOT)));
   closefile(createfile(tree->root, "data", nil, DMDIR | 0500, nil));
+  closefile(createfile(
+    walkfile(tree->root, "data"),
+    "sprite",
+    nil,
+    0400,
+    create_aux(SPRITE_DATA)));
+  closefile(createfile(
+    walkfile(tree->root, "data"),
+    "audio",
+    nil,
+    0400,
+    create_aux(AUDIO_DATA)));
+  closefile(createfile(
+    walkfile(tree->root, "data"),
+    "text",
+    nil,
+    0400,
+    create_aux(TEXT_DATA)));
   closefile(createfile(tree->root, "realms", nil, 0400, create_aux(REALMS)));
-  closefile(
-    createfile(tree->root, "universe", nil, 0600, create_aux(UNIVERSE)));
-  /*String** carts = listdir("carts/");
-  cart = carts;
-
-  while (*cart) {
-    // just concatenate the carts into a multiline string, and put it in
-  CARTS.data
-  }*/
+  closefile(createfile(
+    tree->root,
+    "universe",
+    nil,
+    DMAPPEND | 0600,
+    create_aux(UNIVERSE)));
 
   if (argc >= 3) {
     if (mtpt != nil && access(mtpt, AEXIST) < 0 && access(mtpt, AEXIST) < 0)