diff --git a/editor/editor.lisp b/editor/editor.lisp
index 21fbebb..3d8a5b1 100644
--- a/editor/editor.lisp
+++ b/editor/editor.lisp
@@ -753,7 +753,12 @@ Additionally ensures correct line numbers on the way, as a bonus."
   (clear-screen)
   (redisplay-view (current-view *editor*)))
 
+(defparameter *refresh-asm-functions-p* nil
+  "If non-NIL, reload asm function addresses from listing before every compile.")
+
 (defun com-compile-buffer ()
+  (when *refresh-asm-functions-p*
+    (usc:usc-init))
   (let* ((src (buffer-string (current-buffer *editor*)))
          (bytes
            (handler-case
@@ -777,7 +782,8 @@ Additionally ensures correct line numbers on the way, as a bonus."
                                          :element-type '(unsigned-byte 8)
                                          :if-exists :supersede)
           (dolist (byte bytes)
-            (write-byte byte output)))))))
+            (write-byte byte output)))
+        (usc::send-data-to-c64 (coerce bytes 'vector))))))
 
 
 
diff --git a/host/src/STARTUP.s b/host/src/STARTUP.s
index bc9ebc8..60fb38f 100755
--- a/host/src/STARTUP.s
+++ b/host/src/STARTUP.s
@@ -70,14 +70,10 @@
         ;; Disable maskeble interups (not all)
         SEI
         ;; Disable BASIC ROM mohahaha
+	;; https://www.c64-wiki.com/wiki/Bank_Switching
         LDA #%11111110
         AND $0001
         STA $0001
-        ; https://www.c64-wiki.com/wiki/Bank_Switching
-        ; Disable IO, CHAREN =0
-        LDA #%11111011
-        AND $0001
-        STA $0001
 
         ;;Disable non maskable interupts
         ;;https://codebase64.org/doku.php?id=base:nmi_lock_without_kernal
diff --git a/host/src/loader.s b/host/src/loader.s
index 2aa5360..2fb8035 100644
--- a/host/src/loader.s
+++ b/host/src/loader.s
@@ -20,7 +20,7 @@
 
 ;; More documentation on the Joystick port can be found here: https://www.c64-wiki.com/wiki/Joystick
 
-	progdest	=	$fe
+	progdest	=	$fd
 	CLKMASK		=	%00000010
 	CTRL1		=	$DC01
 
@@ -55,8 +55,10 @@ download_userprog:
 
 	lda #$00
 	sta progdest
+	sta progdest_backup
 	lda #$c0
 	sta progdest+1
+	sta progdest_backup+1
 
 	;; change border color for debugging purposes
 	ldx #$02		; X needed for more than that debug color
@@ -86,6 +88,7 @@ wait_for_bit_start:
 	dex
 	lda BYTE
 	sta LEN,x
+	sta $4010,x
 	txa
 	bne @notdone
 	;; Computing stop address
@@ -101,9 +104,12 @@ wait_for_bit_start:
 	;; Byte finished, storing
 	lda BYTE
 	sta (progdest), y
+	inc progdest_backup
 	inc z:progdest
 	bne @noinchi
+	inc progdest_backup+1
 	inc z:progdest+1
+
 @noinchi:
 	;; Comparing progdest against stop address
 	lda z:progdest
@@ -131,20 +137,26 @@ wait_for_bit_end:
 	jmp wait_for_bit_start
 
 done:
-	lda #$01
+	lda #CLKMASK
+@loop:
+	bit CTRL1
+	bne @loop
 	cli
 	clc
+	lda #$01
 	rts
 
 error:
 	;; TODO
 	cli
 	sec
+	lda #$07
+	sta $d020
 	jmp $c000
 	rts
 
-BYTE		= $400
-LEN		= $402
+BYTE:		.byte 0
+LEN:		.word $0000
 stop:		.word $0000
-loaded:		.byte 0
+progdest_backup = $4094
 .endscope
diff --git a/host/src/mainloop.s b/host/src/mainloop.s
index 61f670a..6612125 100644
--- a/host/src/mainloop.s
+++ b/host/src/mainloop.s
@@ -11,31 +11,46 @@
 ;; 	.endrep
 
 @waitstart: ;; Wait until joystick 2 has been pulled down to start the program
+	dec $d020
 	lda $dc00
 	and #$02
 	bne @waitstart
 
 	jsr setup_loader
-	inc $d020
+
+	pha
 @trying:
-	dec $d020
+	pla
+	tax
+	inx
+	stx $d020
+	txa
+	pha
+
 	jsr maybe_download_userprog
 	beq @trying
 .endscope
 
+	lda #$0d
+	sta $d020
+
 .scope mainloop
 ml:
 	USERPROG	=	$C000
 	RASTER		=	$D012
-	;; Currently no code for fetching new programs, since we're testing with
-	;; batch compiled version of the whole to begin with.
 
-	;; Bank in character ROM
-	lda #%11111011
-	and $01
+	;; Bank out character ROM, I/O in
+	lda #%00000100
+	ora $01
 	sta $01
 
-	;;jsr maybe_download_userprog
+	jsr maybe_download_userprog
+	beq @nochange
+	ldx #$00
+	stx FRAMECOUNT
+	inx
+	sta FIRSTTIME
+@nochange:
 	jsr USERPROG
 
 	;; Bank out character ROM, I/O in
@@ -47,6 +62,8 @@ ml:
 	cpy #$66
 	beq @framewait
 	inc FRAMECOUNT
+	lda #$00
+	sta FIRSTTIME
 	jmp ml
 .endscope
 
@@ -55,4 +72,23 @@ ml:
 	rts
 .endproc
 
+.proc first			; user-procedure
+	lda FIRSTTIME
+	rts
+.endproc
+
+.proc bitand			; user-procedure
+	lda ARGVEC+0
+	and ARGVEC+1
+	rts
+.endproc
+
+.proc bitxor			; user-procedure
+	lda ARGVEC+0
+	eor ARGVEC+1
+	rts
+.endproc
+
+
 FRAMECOUNT:	.byte 0
+FIRSTTIME:	.byte 1
diff --git a/host/src/routines/memory/clear_screen.s b/host/src/routines/memory/clear_screen.s
index e55edb8..2fad099 100644
--- a/host/src/routines/memory/clear_screen.s
+++ b/host/src/routines/memory/clear_screen.s
@@ -2,7 +2,7 @@
 
 ;; Sets memory in 'A'-registry to all addresses from 'A_start' until 'A_start' + 'length'
 ;; Modifies A, X and A_start
-.proc clear_screen
+.proc clear_screen 		; user-procedure
         .include "mem.inc"
         VIC_bank = $4000
         length_ = $1f40
diff --git a/user-side-compiler/populate-asm-functions.lisp b/user-side-compiler/populate-asm-functions.lisp
index 83d9dae..bade850 100644
--- a/user-side-compiler/populate-asm-functions.lisp
+++ b/user-side-compiler/populate-asm-functions.lisp
@@ -68,8 +68,8 @@
                          (parse-asm-declaration main-text)
                        (list name address declaration)))))
 
-(defparameter *program-listing-filepath* #P"../host/build/program.lst")
-(defparameter *program-build-filepath* #P"../host/build.sh")
+(defparameter *program-listing-filepath* #P"../host/build/host.lst")
+(defparameter *program-build-filepath* #P"../host/Makefile")
 
 (defun check-for-asm-build-script ()
   (do ((path *program-build-filepath*))
@@ -90,7 +90,9 @@
          (progn
            (uiop:chdir (make-pathname :defaults script-path
                                       :name nil :type nil))
-           (uiop:run-program (namestring
+           (uiop:run-program "make -"
+                             #+(or)
+                             (namestring
                               (make-pathname :defaults script-path
                                              :directory '(:relative ".")))))
       (uiop:chdir current-dir))))