diff --git a/doc/glue-code.md b/doc/glue-code.md
index 43ffbde..275bd4f 100644
--- a/doc/glue-code.md
+++ b/doc/glue-code.md
@@ -65,12 +65,9 @@ look like:
 
 Once this is written, you can build it with `zasm`, which takes code from stdin
 and spits binary to stdout. Because out code has includes, however, you need
-to supply zasm with a block device containing a CFS containing the files to
-include. This sounds, compicated, but it's managed by the `tools/zasm.sh` shell
-script. The invocation would look like (it builds a CFS with the contents of
-both `kernel/` and `apps/` folders):
+to supply zasm with include folders or files. The invocation would look like
 
-    tools/zasm.sh kernel/ apps/ < glue.asm > collapseos.bin
+    emul/zasm/zasm kernel/ apps/ < glue.asm > collapseos.bin
 
 ## Building zasm
 
@@ -79,7 +76,7 @@ Collapse OS has its own assembler written in z80 assembly. We call it
 but because it is written in z80 assembler, it needs to be emulated (with
 [libz80][libz80]).
 
-So, the first step is to build zasm. Open `tools/emul/README.md` and follow
+So, the first step is to build zasm. Open `emul/README.md` and follow
 instructions there.
 
 ## Platform constants
@@ -162,5 +159,5 @@ and this much depends on the part you select. But if you want a shell, you will
 usually end it with `basStart`, which never returns.
 
 [rc2014]: https://rc2014.co.uk/
-[zasm]: ../tools/emul/README.md
+[zasm]: ../emul/README.md
 [libz80]: https://github.com/ggambetta/libz80
diff --git a/emul/Makefile b/emul/Makefile
index 14e8938..ef0fa05 100644
--- a/emul/Makefile
+++ b/emul/Makefile
@@ -4,19 +4,19 @@ KERNEL = ../kernel
 APPS = ../apps
 ZASMBIN = zasm/zasm
 AVRABIN = zasm/avra
-ZASMSH = ./zasm.sh
 SHELLAPPS = zasm ed
 SHELLTGTS = ${SHELLAPPS:%=cfsin/%}
 CFSIN_CONTENTS = $(SHELLTGTS) cfsin/user.h
 OBJS = emul.o libz80/libz80.o
 SHELLOBJS = $(OBJS) $(CFSPACK_OBJ)
+ZASMOBJS = $(SHELLOBJS)
 
 .PHONY: all
 all: $(TARGETS) $(AVRABIN) $(CFSIN_CONTENTS)
 
 # -o in sync with SHELL_CODE in shell/glue.asm
 shell/shell.bin: shell/glue.asm $(ZASMBIN)
-	$(ZASMSH) $(KERNEL) shell/user.h $(APPS) < shell/glue.asm | tee $@ > /dev/null
+	$(ZASMBIN) $(KERNEL) shell/user.h $(APPS) < shell/glue.asm | tee $@ > /dev/null
 
 shell/shell-bin.h: shell/shell.bin
 	./bin2c.sh KERNEL < shell/shell.bin | tee $@ > /dev/null
@@ -30,17 +30,17 @@ zasm/kernel-bin.h: zasm/kernel.bin
 zasm/zasm-bin.h: zasm/zasm.bin
 	./bin2c.sh USERSPACE < zasm/zasm.bin | tee $@ > /dev/null
 
-$(ZASMBIN): zasm/zasm.c $(OBJS) zasm/kernel-bin.h zasm/zasm-bin.h $(CFSPACK)
-	$(CC) zasm/zasm.c $(OBJS) -o $@
+$(ZASMBIN): zasm/zasm.c $(ZASMOBJS) zasm/kernel-bin.h zasm/zasm-bin.h
+	$(CC) zasm/zasm.c $(ZASMOBJS) -o $@
 
 zasm/avra.bin: $(ZASMBIN)
-	$(ZASMSH) $(KERNEL) $(APPS) zasm/user.h < $(APPS)/zasm/gluea.asm > $@
+	$(ZASMBIN) $(KERNEL) $(APPS) zasm/user.h < $(APPS)/zasm/gluea.asm > $@
 
 zasm/avra-bin.h: zasm/avra.bin
 	./bin2c.sh USERSPACE < zasm/avra.bin | tee $@ > /dev/null
 
-$(AVRABIN): zasm/zasm.c $(OBJS) zasm/kernel-bin.h zasm/avra-bin.h
-	$(CC) -D AVRA zasm/zasm.c $(OBJS) -o $@
+$(AVRABIN): zasm/zasm.c $(ZASMOBJS) zasm/kernel-bin.h zasm/avra-bin.h
+	$(CC) -D AVRA zasm/zasm.c $(ZASMOBJS) -o $@
 
 runbin/runbin: runbin/runbin.c $(OBJS)
 	$(CC) runbin/runbin.c $(OBJS) -o $@
@@ -52,20 +52,20 @@ libz80/libz80.o: libz80/z80.c
 emul.o: emul.c
 	$(CC) -c -o emul.o emul.c
 
-$(CFSPACK):
+$(CFSPACK_OBJ): ${@:%.o=%.c}
 	$(MAKE) -C ../tools/cfspack
 
 # -o in sync with USER_CODE in shell/user.h
 $(SHELLTGTS): $(ZASMBIN)
-	$(ZASMSH) -o 42 $(KERNEL) $(APPS) shell/user.h < $(APPS)/${@:cfsin/%=%}/glue.asm > $@
+	$(ZASMBIN) -o 42 $(KERNEL) $(APPS) shell/user.h < $(APPS)/${@:cfsin/%=%}/glue.asm > $@
 
 cfsin/user.h: shell/user.h
 	cp shell/user.h $@
 
 .PHONY: updatebootstrap
 updatebootstrap: $(ZASMBIN)
-	$(ZASMSH) $(KERNEL) < zasm/glue.asm > zasm/kernel.bin
-	$(ZASMSH) $(KERNEL) $(APPS) zasm/user.h < $(APPS)/zasm/glue.asm > zasm/zasm.bin
+	$(ZASMBIN) $(KERNEL) < zasm/glue.asm > zasm/kernel.bin
+	$(ZASMBIN) $(KERNEL) $(APPS) zasm/user.h < $(APPS)/zasm/glue.asm > zasm/zasm.bin
 
 .PHONY: clean
 clean:
diff --git a/emul/zasm.sh b/emul/zasm.sh
deleted file mode 100755
index e196b61..0000000
--- a/emul/zasm.sh
+++ /dev/null
@@ -1,44 +0,0 @@
-#!/usr/bin/env bash
-
-# Calls emul/zasm/zasm in a convenient manner by wrapping specified
-# paths to include in a single CFS file and then pass that file to zasm.
-# Additionally, it takes a "-o" argument to set the initial ".org" of the
-# binary. For example, "zasm.sh -o 4f < foo.asm" assembles foo.asm as if it
-# started with the line ".org 0x4f00".
-
-# The -a flag makes us switch to the AVR assembler
-
-# readlink -f doesn't work with macOS's implementation
-# so, if we can't get readlink -f to work, try python with a realpath implementation
-ABS_PATH=$(readlink -f "$0" || python -c "import os; print(os.path.realpath('$0'))")
-DIR=$(dirname "${ABS_PATH}")
-ZASMBIN="${DIR}/zasm/zasm"
-
-usage() { echo "Usage: $0 [-a] [-o <hexorg>] <paths-to-include>..." 1>&2; exit 1; }
-
-org='00'
-while getopts ":ao:" opt; do
-    case "${opt}" in
-        a)
-            ZASMBIN="${DIR}/zasm/avra"
-            ;;
-        o)
-            org=${OPTARG}
-            ;;
-        *)
-            usage
-            ;;
-    esac
-done
-shift $((OPTIND-1))
-
-# wrapper around ./zasm/zasm that prepares includes CFS prior to call
-CFSPACK="${DIR}/../tools/cfspack/cfspack"
-INCCFS=$(mktemp)
-
-"${CFSPACK}" -p "*.h" -p "*.asm" -p "*.bin" "$@" > "${INCCFS}" 
-
-"${ZASMBIN}" "${org}" "${INCCFS}"
-RES=$?
-rm "${INCCFS}"
-exit $RES
diff --git a/emul/zasm/zasm.c b/emul/zasm/zasm.c
index ccb8c33..5fc7e35 100644
--- a/emul/zasm/zasm.c
+++ b/emul/zasm/zasm.c
@@ -1,7 +1,10 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
+#include <unistd.h>
+#include <libgen.h>
 #include "../emul.h"
+#include "../../tools/cfspack/cfs.h"
 #include "kernel-bin.h"
 #ifdef AVRA
 #include "avra-bin.h"
@@ -51,6 +54,7 @@
 // By default, we don't spit what zasm prints. Too noisy. Define VERBOSE if
 // you want to spit this content to stderr.
 //#define VERBOSE
+#define MAX_FSDEV_SIZE 0x80000
 
 // STDIN buffer, allows us to seek and tell
 static uint8_t inpt[STDIN_BUFSIZE];
@@ -58,8 +62,7 @@ static int inpt_size;
 static int inpt_ptr;
 static uint8_t middle_of_seek_tell = 0;
 
-static uint8_t fsdev[0x80000] = {0};
-static uint32_t fsdev_size = 0;
+static uint8_t fsdev[MAX_FSDEV_SIZE] = {0};
 static uint32_t fsdev_ptr = 0;
 static uint8_t fsdev_seek_tell_cnt = 0;
 
@@ -88,7 +91,7 @@ static uint8_t iord_stdin_seek()
 
 static uint8_t iord_fsdata()
 {
-    if (fsdev_ptr < fsdev_size) {
+    if (fsdev_ptr < MAX_FSDEV_SIZE) {
         return fsdev[fsdev_ptr++];
     } else {
         return 0;
@@ -99,7 +102,7 @@ static uint8_t iord_fsseek()
 {
     if (fsdev_seek_tell_cnt != 0) {
         return fsdev_seek_tell_cnt;
-    } else if (fsdev_ptr >= fsdev_size) {
+    } else if (fsdev_ptr >= MAX_FSDEV_SIZE) {
         return 1;
     } else {
         return 0;
@@ -130,7 +133,7 @@ static void iowr_stdin_seek(uint8_t val)
 
 static void iowr_fsdata(uint8_t val)
 {
-    if (fsdev_ptr < fsdev_size) {
+    if (fsdev_ptr < MAX_FSDEV_SIZE) {
         fsdev[fsdev_ptr++] = val;
     }
 }
@@ -159,11 +162,50 @@ static void iowr_stderr(uint8_t val)
 #endif
 }
 
+void usage()
+{
+    fprintf(stderr, "Usage: zasm [-o org] [include-dir-or-file...] < source > binary\n");
+}
+
 int main(int argc, char *argv[])
 {
-    if (argc > 3) {
-        fprintf(stderr, "Too many args\n");
-        return 1;
+    char *init_org = "00";
+    while (1) {
+        int c = getopt(argc, argv, "o:");
+        if (c < 0) {
+            break;
+        }
+        switch (c) {
+            case 'o':
+                init_org = optarg;
+                if (strlen(init_org) != 2) {
+                    fprintf(stderr, "Initial org must be a two-character hex string");
+                }
+                break;
+            default:
+                usage();
+                return 1;
+        }
+    }
+    if (argc-optind > 0) {
+        FILE *fp = fmemopen(fsdev, MAX_FSDEV_SIZE, "w");
+        set_spit_stream(fp);
+        char *patterns[4] = {"*.h", "*.asm", "*.bin", 0};
+        for (int i=optind; i<argc; i++) {
+            int res;
+            if (is_regular_file(argv[i])) {
+                // special case: just one file
+                res = spitblock(argv[i], basename(argv[i]));
+            } else {
+                res = spitdir(argv[i], "", patterns);
+            }
+            if (res != 0) {
+                fprintf(stderr, "Error while building the include CFS.\n");
+                fclose(fp);
+                return 1;
+            }
+        }
+        fclose(fp);
     }
     Machine *m = emul_init();
     m->iord[STDIO_PORT] = iord_stdio;
@@ -182,31 +224,9 @@ int main(int argc, char *argv[])
     for (int i=0; i<sizeof(USERSPACE); i++) {
         m->mem[i+USER_CODE] = USERSPACE[i];
     }
-    char *init_org = "00";
-    if (argc >= 2) {
-        init_org = argv[1];
-        if (strlen(init_org) != 2) {
-            fprintf(stderr, "Initial org must be a two-character hex string");
-        }
-    }
     // glue.asm knows that it needs to fetch these arguments at this address.
     m->mem[0xff00] = init_org[0];
     m->mem[0xff01] = init_org[1];
-    fsdev_size = 0;
-    if (argc == 3) {
-        FILE *fp = fopen(argv[2], "r");
-        if (fp == NULL) {
-            fprintf(stderr, "Can't open file %s\n", argv[1]);
-            return 1;
-        }
-        int c = fgetc(fp);
-        while (c != EOF) {
-            fsdev[fsdev_size] = c;
-            fsdev_size++;
-            c = fgetc(fp);
-        }
-        fclose(fp);
-    }
     // read stdin in buffer
     inpt_size = 0;
     inpt_ptr = 0;
diff --git a/recipes/rc2014/Makefile b/recipes/rc2014/Makefile
index 0c9ad10..190d3aa 100644
--- a/recipes/rc2014/Makefile
+++ b/recipes/rc2014/Makefile
@@ -1,9 +1,10 @@
 TARGET = os.bin
-ZASM = ../../tools/zasm.sh
-KERNEL = ../../kernel
-APPS = ../../apps
+BASEDIR = ../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
 
 .PHONY: all
 all: $(TARGET)
 $(TARGET): glue.asm
-	$(ZASM) $(KERNEL) $(APPS) < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
diff --git a/recipes/rc2014/README.md b/recipes/rc2014/README.md
index a137888..7c88552 100644
--- a/recipes/rc2014/README.md
+++ b/recipes/rc2014/README.md
@@ -77,7 +77,7 @@ is decoupled from the ACIA and can get its IO from anything. See comments in
 
 We only have the shell to build, so it's rather straightforward:
 
-    ../../tools/zasm.sh ../../kernel < glue.asm > os.bin
+    ../../emul/zasm/zasm ../../kernel < glue.asm > os.bin
 
 Running `make` will also work.
 
diff --git a/recipes/rc2014/eeprom/Makefile b/recipes/rc2014/eeprom/Makefile
index 33fd356..d3a2821 100644
--- a/recipes/rc2014/eeprom/Makefile
+++ b/recipes/rc2014/eeprom/Makefile
@@ -1,10 +1,11 @@
 TARGET = os.bin
-ZASM = ../../../tools/zasm.sh
-KERNEL = ../../../kernel
-APPS = ../../../apps
+BASEDIR = ../../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
 
 .PHONY: all
 all: $(TARGET)
 $(TARGET): glue.asm
-	$(ZASM) $(KERNEL) $(APPS) < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
 
diff --git a/recipes/rc2014/eeprom/glue.asm b/recipes/rc2014/eeprom/glue.asm
index 3c35733..06ba0fe 100644
--- a/recipes/rc2014/eeprom/glue.asm
+++ b/recipes/rc2014/eeprom/glue.asm
@@ -33,7 +33,6 @@ jp	aciaInt
 .equ	STDIO_PUTC	aciaPutC
 .inc "stdio.asm"
 
-.inc "lib/args.asm"
 .equ	AT28W_RAMSTART	STDIO_RAMEND
 .inc "at28w/main.asm"
 
diff --git a/recipes/rc2014/ps2/Makefile b/recipes/rc2014/ps2/Makefile
index 983db19..a4eed73 100644
--- a/recipes/rc2014/ps2/Makefile
+++ b/recipes/rc2014/ps2/Makefile
@@ -2,9 +2,10 @@ PROGNAME = ps2ctl
 AVRDUDEMCU ?= t45
 AVRDUDEARGS ?= -c usbtiny -P usb 
 TARGETS = $(PROGNAME).hex os.bin
-ZASM = ../../../tools/zasm.sh
-KERNEL = ../../../kernel
-APPS = ../../../apps
+BASEDIR = ../../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
 
 # Rules
 
@@ -14,13 +15,13 @@ all: $(TARGETS)
 	@echo Done!
 
 send: $(PROGNAME).hex
-	avrdude $(AVRDUDEARGS) -p $(AVRDUDEMCU) -U flash:w:$<
+	avrdude $(AVRDUDEARGS) -p $(AVRDUDEMCU) -U flash:w:$(PROGNAME).hex
 
 $(PROGNAME).hex: $(PROGNAME).asm
-	avra -o $@ $<
+	avra -o $@ $(PROGNAME).asm
 
 os.bin: glue.asm
-	$(ZASM) $(KERNEL) $(APPS) < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
 
 clean:
 	rm -f $(TARGETS) *.eep.hex *.obj os.bin
diff --git a/recipes/rc2014/sdcard/Makefile b/recipes/rc2014/sdcard/Makefile
index 61c963b..5ce8baa 100644
--- a/recipes/rc2014/sdcard/Makefile
+++ b/recipes/rc2014/sdcard/Makefile
@@ -1,19 +1,19 @@
 TARGETS = os.bin cfsin/helo
-TOOLS = ../../../tools
-ZASM = $(TOOLS)/zasm.sh
-KERNEL = ../../../kernel
-APPS = ../../../apps
-CFSPACK = $(TOOLS)/cfspack/cfspack
+BASEDIR = ../../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
+CFSPACK = $(BASEDIR)/tools/cfspack/cfspack
 
 .PHONY: all
 all: $(TARGETS) sdcard.cfs
 os.bin: glue.asm 
 cfsin/helo: helo.asm
 $(TARGETS):
-	$(ZASM) $(KERNEL) $(APPS) < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
 
 $(CFSPACK):
-	make -C $(TOOLS)/cfspack
+	make -C $(BASEDIR)/tools/cfspack
 
 sdcard.cfs: cfsin $(CFSPACK)
-	$(CFSPACK) $< > $@
+	$(CFSPACK) cfsin > $@
diff --git a/recipes/rc2014/zasm/Makefile b/recipes/rc2014/zasm/Makefile
index 3bd165a..8562a27 100644
--- a/recipes/rc2014/zasm/Makefile
+++ b/recipes/rc2014/zasm/Makefile
@@ -1,21 +1,20 @@
 SHELLAPPS = zasm sdct memt at28w
 APPTARGETS = ${SHELLAPPS:%=cfsin/%} 
 CFSTARGETS = $(APPTARGETS) cfsin/user.h
-BASE = ../../..
-TOOLS = $(BASE)/tools
-ZASM = $(TOOLS)/zasm.sh
-KERNEL = $(BASE)/kernel
-APPS = $(BASE)/apps
-CFSPACK = $(TOOLS)/cfspack/cfspack
+BASEDIR = ../../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
+CFSPACK = $(BASEDIR)/tools/cfspack/cfspack
 
 .PHONY: all
 all: os.bin sdcard.cfs
 
 os.bin: glue.asm
-	$(ZASM) $(KERNEL) $(APPS) < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
 
 $(CFSPACK):
-	make -C $(TOOLS)/cfspack
+	make -C $(BASEDIR)/tools/cfspack
 
 sdcard.cfs: $(CFSTARGETS) $(CFSPACK)
 	$(CFSPACK) cfsin > $@
@@ -24,7 +23,7 @@ $(APPTARGETS): $(ZASMBIN)
 	$(ZASM) $(KERNEL) $(APPS) user.h < $(APPS)/${@:cfsin/%=%}/glue.asm > $@
 
 cfsin/user.h: user.h
-	cp $< $@
+	cp user.h $@
 
 .PHONY: clean
 clean:
diff --git a/recipes/sms/Makefile b/recipes/sms/Makefile
index 6e7bbe1..b1145e5 100644
--- a/recipes/sms/Makefile
+++ b/recipes/sms/Makefile
@@ -1,9 +1,10 @@
 TARGET = os.sms
-ZASM = ../../tools/zasm.sh
-KERNEL = ../../kernel
-APPS = ../../apps
+BASEDIR = ../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
 
 .PHONY: all
 all: $(TARGET)
 $(TARGET): glue.asm
-	$(ZASM) $(KERNEL) $(APPS) < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
diff --git a/recipes/sms/kbd/Makefile b/recipes/sms/kbd/Makefile
index 64a8b63..b7298de 100644
--- a/recipes/sms/kbd/Makefile
+++ b/recipes/sms/kbd/Makefile
@@ -2,9 +2,10 @@ PROGNAME = ps2ctl
 AVRDUDEMCU ?= t45
 AVRDUDEARGS ?= -c usbtiny -P usb 
 TARGETS = $(PROGNAME).hex os.sms
-ZASM = ../../../tools/zasm.sh
-KERNEL = ../../../kernel
-APPS = ../../../apps
+BASEDIR = ../../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
 
 # Rules
 
@@ -14,13 +15,13 @@ all: $(TARGETS)
 	@echo Done!
 
 send: $(PROGNAME).hex
-	avrdude $(AVRDUDEARGS) -p $(AVRDUDEMCU) -U flash:w:$<
+	avrdude $(AVRDUDEARGS) -p $(AVRDUDEMCU) -U flash:w:$(PROGNAME).hex
 
 $(PROGNAME).hex: $(PROGNAME).asm
-	avra -o $@ $<
+	avra -o $@ $(PROGNAME).asm
 
 os.sms: glue.asm
-	$(ZASM) $(KERNEL) $(APPS) < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
 
 clean:
 	rm -f $(TARGETS) *.eep.hex *.obj os.bin
diff --git a/recipes/sms/romasm/Makefile b/recipes/sms/romasm/Makefile
index 606a85a..5bcad39 100644
--- a/recipes/sms/romasm/Makefile
+++ b/recipes/sms/romasm/Makefile
@@ -1,20 +1,21 @@
-ZASM = ../../../tools/zasm.sh
-KERNEL = ../../../kernel
-APPS = ../../../apps
+BASEDIR = ../../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
 
 .PHONY: all clean
 all: os.sms
 
 # -o value synced with offset in glue.asm
 ed.bin: $(APPS)/ed/glue.asm
-	$(ZASM) -o 19 $(KERNEL) $(APPS) user.h < $< > $@
+	$(ZASM) -o 1f $(KERNEL) $(APPS) user.h < $(APPS)/ed/glue.asm > $@
 
 # -o value synced with offset in glue.asm
 zasm.bin: $(APPS)/zasm/glue.asm
-	$(ZASM) -o 1d $(KERNEL) $(APPS) user.h < $< > $@
+	$(ZASM) -o 24 $(KERNEL) $(APPS) user.h < $(APPS)/zasm/glue.asm > $@
 
 os.sms: glue.asm ed.bin zasm.bin
-	$(ZASM) $(KERNEL) $(APPS) ed.bin zasm.bin < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) ed.bin zasm.bin < glue.asm > $@
 
 clean:
 	rm -f os.sms ed.bin zasm.bin
diff --git a/recipes/ti84/Makefile b/recipes/ti84/Makefile
index f98b262..cd4d28d 100644
--- a/recipes/ti84/Makefile
+++ b/recipes/ti84/Makefile
@@ -1,18 +1,19 @@
 TARGET = os.rom
-ZASM = ../../tools/zasm.sh
-KERNEL = ../../kernel
-APPS = ../../apps
+BASEDIR = ../..
+ZASM = $(BASEDIR)/emul/zasm/zasm
+KERNEL = $(BASEDIR)/kernel
+APPS = $(BASEDIR)/apps
 MKTIUPGRADE = mktiupgrade
 
 .PHONY: all
 all: $(TARGET)
 $(TARGET): glue.asm
-	$(ZASM) $(KERNEL) $(APPS) < $< > $@
+	$(ZASM) $(KERNEL) $(APPS) < glue.asm > $@
 	truncate -s 1M $@
 
 os.8xu: $(TARGET)
-	$(MKTIUPGRADE) -p -k keys/0A.key -d TI-84+ $< $@ 00
+	$(MKTIUPGRADE) -p -k keys/0A.key -d TI-84+ $(TARGET) $@ 00
 
 .PHONY: send
 send: os.8xu
-	tilp -n --calc ti84+ --cable DirectLink $<
+	tilp -n --calc ti84+ --cable DirectLink os.8xu
diff --git a/tests/Makefile b/tests/Makefile
index 2d24c16..21be294 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -1,5 +1,4 @@
 EMULDIR = ../emul
-CFSPACK = ../tools/cfspack/cfspack
 
 .PHONY: run
 run:
@@ -8,10 +7,3 @@ run:
 	cd zasm && ./runtests.sh
 	cd avra && ./runtests.sh
 	cd shell && ./runtests.sh
-
-$(CFSPACK):
-	$(MAKE) -C ../tools/cfspack
-
-.PHONY: cfs
-cfs: $(CFSPACK)
-	$(CFSPACK) shell/cfsin > shell/test.cfs
diff --git a/tests/avra/runtests.sh b/tests/avra/runtests.sh
index 1ea6e59..e1464dc 100755
--- a/tests/avra/runtests.sh
+++ b/tests/avra/runtests.sh
@@ -1,12 +1,12 @@
 #!/bin/sh -e
 
-ZASM=../../emul/zasm.sh
+ZASM=../../emul/zasm/avra
 AVRINC=../../avr
 
 cmpas() {
     FN=$1
     EXPECTED=$(xxd ${FN%.*}.expected)
-    ACTUAL=$(cat ${FN} | "${ZASM}" -a "${AVRINC}" | xxd)
+    ACTUAL=$(cat ${FN} | "${ZASM}" "${AVRINC}" | xxd)
     if [ "$ACTUAL" = "$EXPECTED" ]; then
         echo ok
     else
diff --git a/tests/shell/runtests.sh b/tests/shell/runtests.sh
index 0b962eb..d62f240 100755
--- a/tests/shell/runtests.sh
+++ b/tests/shell/runtests.sh
@@ -6,7 +6,7 @@ SHELL="${EMULDIR}/shell/shell"
 replay() {
     fn=$1
     replayfn=${fn%.*}.expected
-    ACTUAL=$("${SHELL}" -f test.cfs < "${fn}" 2> /dev/null)
+    ACTUAL=$("${SHELL}" < "${fn}" 2> /dev/null)
     EXPECTED=$(cat ${replayfn})
     if [ "$ACTUAL" = "$EXPECTED" ]; then
         echo ok
diff --git a/tests/shell/test.cfs b/tests/shell/test.cfs
deleted file mode 100644
index f9fb1b6..0000000
Binary files a/tests/shell/test.cfs and /dev/null differ
diff --git a/tests/unit/runtests.sh b/tests/unit/runtests.sh
index 1a42d16..09318b9 100755
--- a/tests/unit/runtests.sh
+++ b/tests/unit/runtests.sh
@@ -3,7 +3,7 @@ set -e
 # TODO: find POSIX substitute to that PIPESTATUS thing
 
 BASE=../..
-ZASM="${BASE}/emul/zasm.sh"
+ZASM="${BASE}/emul/zasm/zasm"
 RUNBIN="${BASE}/emul/runbin/runbin"
 KERNEL="${BASE}/kernel"
 APPS="${BASE}/apps"
diff --git a/tests/zasm/errtests.sh b/tests/zasm/errtests.sh
index 741afa7..54bfd1f 100755
--- a/tests/zasm/errtests.sh
+++ b/tests/zasm/errtests.sh
@@ -2,7 +2,7 @@
 
 # no "set -e" because we test errors
 
-ZASM=../../emul/zasm.sh
+ZASM=../../emul/zasm/zasm
 
 chkerr() {
     echo "Check that '$1' results in error $2"
diff --git a/tests/zasm/runtests.sh b/tests/zasm/runtests.sh
index 832b972..aa8edc8 100755
--- a/tests/zasm/runtests.sh
+++ b/tests/zasm/runtests.sh
@@ -3,7 +3,7 @@
 BASE=../..
 KERNEL="${BASE}/kernel"
 APPS="${BASE}/apps"
-ZASM="${BASE}/emul/zasm.sh"
+ZASM="${BASE}/emul/zasm/zasm"
 
 cmpas() {
     FN=$1