diff --git a/apps/Makefile.in b/apps/Makefile.in
index 146c8e78e8..18c2aa6534 100644
--- a/apps/Makefile.in
+++ b/apps/Makefile.in
@@ -17,7 +17,7 @@ LIBS = ../api/boinc_api.o ../api/mfile.o ../lib/parse.o ../lib/filesys.o ../lib/
 
 CLIBS = @LIBS@
 
-APPS = upper_case concat uc_slow concat_slow 1sec uc_cpu
+APPS = upper_case concat 1sec
 
 .C.o:
 	$(CC) -c -o $*.o $<
@@ -32,15 +32,6 @@ upper_case: upper_case.o
 concat: concat.o
 	$(CC) concat.o $(LIBS) -o concat
 
-concat_slow: concat_slow.o
-	$(CC) concat_slow.o $(LIBS) -o concat_slow
-
-uc_slow: uc_slow.o
-	$(CC) uc_slow.o $(LIBS) -o uc_slow
-
-uc_cpu: uc_cpu.o
-	$(CC) uc_cpu.o $(LIBS) -o uc_cpu
-
 1sec: 1sec.o
 	$(CC) 1sec.o $(LIBS) -o 1sec
 
@@ -48,8 +39,6 @@ install: all
 	-mkdir -p $(INSTALL_DIR)/apps
 	cp upper_case $(INSTALL_DIR)/apps/upper_case
 	cp concat $(INSTALL_DIR)/apps/concat
-	cp uc_slow $(INSTALL_DIR)/apps/uc_slow
-	cp concat_slow $(INSTALL_DIR)/apps/concat_slow
 	cp 1sec $(INSTALL_DIR)/apps/1sec
 
 uninstall: 
diff --git a/apps/concat.C b/apps/concat.C
index 4498f24301..c84bbe27e2 100644
--- a/apps/concat.C
+++ b/apps/concat.C
@@ -17,43 +17,122 @@
 // Contributor(s):
 //
 
-// concat file1 ... filen outfile
+// concat [-run_slow] file1 ... filen outfile
 //
 // concatenate files, write to outfile
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+
+#include "filesys.h"
 #include "boinc_api.h"
 
-void file_append(FILE* in, FILE* out) {
-    char buf[1024];
-    int n;
+int run_slow = 0;
+
+#define CHECKPOINT_FILE "concat_state"
+
+int do_checkpoint(MFILE& mf, int filenum, int nchars ) {
+    int retval;
+    char resolved_name[512],res_name2[512];
+
+    FILE* f = fopen("temp", "w");
+    if (!f) return 1;
+    fprintf(f, "%d %d", filenum, nchars);
+    fclose(f);
+
+    fprintf(stderr, "APP: concat checkpointing\n");
+
+    boinc_resolve_filename( CHECKPOINT_FILE, res_name2 );
+
+    retval = mf.flush();
+    if (retval) return retval;
+    retval = boinc_rename("temp", res_name2);
+    if (retval) return retval;
+
+    return 0;
+}
+
+void file_append(FILE* in, MFILE &out, int skip, int filenum) {
+    char buf[1];
+    int n,nread,retval;
+
+    fseek( in, skip, SEEK_SET );
+    nread = skip;
 
     while (1) {
-        n = fread(buf, 1, 1024, in);
+        n = fread(buf, 1, 1, in);
         if (n == 0) break;
-        fwrite(buf, 1, n, out);
+        out.write(buf, 1, n);
+        nread += n;
+
+        if( boinc_time_to_checkpoint() ) {
+            fprintf( stderr, "Checkpoint.\n" );
+            retval = do_checkpoint( out, filenum, nread );
+            if( retval ) {
+                fprintf( stderr, "APP: concat checkpoint failed %d\n", retval );
+                exit(1);
+            }
+            boinc_checkpoint_completed();
+        }
+
+        if (run_slow) sleep(1);
     }
 }
 
+#ifdef _WIN32
+#include <windows.h>
+int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR Args, int WinMode) {
+    LPWSTR command_line;
+    LPWSTR *args;
+    char* argv[100];
+    int i, argc;
+
+    command_line = GetCommandLineW();
+    args = CommandLineToArgvW(command_line, &argc);
+
+    // uh, why did MS have to "improve" on char*?
+
+    for (i=0; i<argc; i++) {
+        argv[i] = (char*)args[i];
+    }
+    return main(argc, argv);
+}
+#endif
+
 int main(int argc, char** argv) {
-    FILE* in, *out;
+    FILE* in, *state;
+    MFILE out;
     char file_name[512];
     int i;
+    int file_num,nchars,retval;
+    char *mode;
 
     boinc_init();
     fprintf(stderr, "APP: concat: starting, argc %d\n", argc);
+
     for (i=0; i<argc; i++) {
         fprintf(stderr, "APP: concat: argv[%d] is %s\n", i, argv[i]);
+        if (!strcmp(argv[i], "-run_slow")) run_slow = 1;
+    }
+    boinc_resolve_filename( CHECKPOINT_FILE, file_name );
+    state = fopen( file_name, "r" );
+    if( state ) {
+        fscanf( state, "%d %d", &file_num, &nchars );
+        mode = "a";
+    } else {
+        file_num = (run_slow ? 2 : 1);
+        nchars = 0;
+        mode = "w";
     }
     boinc_resolve_filename( argv[argc-1], file_name );
     fprintf( stderr, "res: %s\n", file_name );
-    out = fopen(file_name, "w");
-    if (!out) {
+    retval = out.open(file_name, mode);
+    if (retval) {
         fprintf(stderr, "APP: concat: can't open out file %s\n", argv[argc-1]);
         exit(1);
     }
-    for (i=1; i<argc-1; i++) {
+    for (i=file_num; i<argc-1; i++) {
         boinc_resolve_filename( argv[i], file_name );
         fprintf( stderr, "res: %s\n", file_name );
         in = fopen(file_name, "r");
@@ -61,10 +140,11 @@ int main(int argc, char** argv) {
             fprintf(stderr, "APP: concat: can't open in file %s\n", argv[i]);
             exit(1);
         }
-        file_append(in, out);
+        file_append(in, out, nchars, i);
+        nchars = 0;
         fclose(in);
     }
-    fclose(out);
+    out.close();
     fprintf(stderr, "APP: concat: done\n");
     boinc_finish(0);
     return 0;
diff --git a/apps/concat_slow.C b/apps/concat_slow.C
deleted file mode 100644
index dee000c811..0000000000
--- a/apps/concat_slow.C
+++ /dev/null
@@ -1,132 +0,0 @@
-// The contents of this file are subject to the Mozilla Public License
-// Version 1.0 (the "License"); you may not use this file except in
-// compliance with the License. You may obtain a copy of the License at
-// http://www.mozilla.org/MPL/ 
-// 
-// Software distributed under the License is distributed on an "AS IS"
-// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
-// License for the specific language governing rights and limitations
-// under the License. 
-// 
-// The Original Code is the Berkeley Open Infrastructure for Network Computing. 
-// 
-// The Initial Developer of the Original Code is the SETI@home project.
-// Portions created by the SETI@home project are Copyright (C) 2002
-// University of California at Berkeley. All Rights Reserved. 
-// 
-// Contributor(s):
-//
-
-// concat file1 ... filen outfile
-//
-// concatenate files, write to outfile
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-#include "filesys.h"
-#include "boinc_api.h"
-
-#define CHECKPOINT_FILE "concat_slow_state"
-
-int do_checkpoint(MFILE& mf, int filenum, int nchars ) {
-    int retval;
-    char resolved_name[512],res_name2[512];
-
-    FILE* f = fopen("temp", "w");
-    if (!f) return 1;
-    fprintf(f, "%d %d", filenum, nchars);
-    fclose(f);
-
-    fprintf(stderr, "APP: concat_slow checkpointing\n");
-
-    boinc_resolve_filename( CHECKPOINT_FILE, res_name2 );
-
-    retval = mf.flush();
-    if (retval) return retval;
-    retval = boinc_rename("temp", res_name2);
-    if (retval) return retval;
-
-    return 0;
-}
-
-void file_append(FILE* in, MFILE &out, int skip, int filenum) {
-    char buf[1];
-    int n,nread,retval;
-
-    fseek( in, skip, SEEK_SET );
-    nread = skip;
-
-    while (1) {
-        n = fread(buf, 1, 1, in);
-        if (n == 0) break;
-        out.write(buf, 1, n);
-        nread += n;
-        fprintf( stderr, "Wrote 1 char.\n" );
-        // Burn cycles
-        for( n=0;n<5000000;n++ )
-            retval += n;
-        if( retval == 0 )
-            n = 1;
-
-        if( boinc_time_to_checkpoint() ) {
-            fprintf( stderr, "Checkpoint.\n" );
-            retval = do_checkpoint( out, filenum, nread );
-            if( retval ) {
-                fprintf( stderr, "APP: concat_slow checkpoint failed %d\n", retval );
-                exit(1);
-            }
-            boinc_checkpoint_completed();
-        }
-        sleep(1);
-    }
-}
-
-int main(int argc, char** argv) {
-    FILE* in, *state;
-    MFILE out;
-    char file_name[512];
-    int i;
-    int file_num,nchars,retval;
-    char *mode;
-
-    boinc_init();
-    fprintf(stderr, "APP: concat: starting, argc %d\n", argc);
-    for (i=0; i<argc; i++) {
-        fprintf(stderr, "APP: concat: argv[%d] is %s\n", i, argv[i]);
-    }
-    boinc_resolve_filename( CHECKPOINT_FILE, file_name );
-    state = fopen( file_name, "r" );
-    if( state ) {
-        fscanf( state, "%d %d", &file_num, &nchars );
-        mode = "a";
-    } else {
-        file_num = 1;
-        nchars = 0;
-        mode = "w";
-    }
-    boinc_resolve_filename( argv[argc-1], file_name );
-    fprintf( stderr, "res: %s\n", file_name );
-    retval = out.open(file_name, mode);
-    if (retval) {
-        fprintf(stderr, "APP: concat: can't open out file %s\n", argv[argc-1]);
-        exit(1);
-    }
-    for (i=file_num; i<argc-1; i++) {
-        boinc_resolve_filename( argv[i], file_name );
-        fprintf( stderr, "res: %s\n", file_name );
-        in = fopen(file_name, "r");
-        if (!in) {
-            fprintf(stderr, "APP: concat: can't open in file %s\n", argv[i]);
-            exit(1);
-        }
-        file_append(in, out, nchars, i);
-        nchars = 0;
-        fclose(in);
-    }
-    out.close();
-    fprintf(stderr, "APP: concat: done\n");
-    boinc_finish(0);
-    return 0;
-}
diff --git a/checkin_notes b/checkin_notes
index 3946046f51..d92d4d5d63 100755
--- a/checkin_notes
+++ b/checkin_notes
@@ -1826,17 +1826,21 @@ David   August 30 2002
         md5_file.C
 
 Eric    September 4, 2002
-    - condensed uc_slow, uc_cpu into upper_case, using command line arguments
+    - condensed uc_slow, uc_cpu into upper_case, concat_slow into concat, using command line arguments
     - changed test_uc to use files rather than stdin/stdout
 
     apps/
         uc_slow.C (removed)
+        concat_slow.C (removed)
         uc_cpu.C (removed)
         upper_case.C
+        concat.C
+        Makefile.in
     lib/
         error_numbers.h
     test/
         test_uc_slow.php
+        test_concat.php
         uc_result
         uc_wu
         ucs_wu
diff --git a/test/test_concat.php b/test/test_concat.php
index 8f3a62336e..32896f790d 100644
--- a/test/test_concat.php
+++ b/test/test_concat.php
@@ -8,14 +8,20 @@
 
     check_env_vars();
     clear_db();
-    clear_data_dirs();
-    create_keys();
+    if (true) {
+        clear_server_dirs(false);
+    } else {
+        clear_server_dirs(true);
+        create_keys();
+    }
+    clear_client_dirs();
     init_client_dirs("prefs1.xml");
     copy_to_download_dir("input");
+    add_project("Test Project");
     add_platform(null);
-    //add_core_client(null);
     add_user("prefs.xml");
     add_app("concat",null,null);
+    add_core_client(null);
     create_work("-appname concat -wu_name concat_wu -wu_template concat_wu -result_template concat_result -nresults 2 input input");
     start_feeder();
     run_client("-exit_when_idle");