diff --git a/vm.scm b/vm.scm
index 5eff5b2..b7b1e26 100644
--- a/vm.scm
+++ b/vm.scm
@@ -11,13 +11,23 @@
 (define (get-u8 port)
   (let ((c (read-char port))) (if (eof-object? c) c (char->integer c))))
 (define (open-rom path) (open-input-file path #:binary))
-(define (get-date-time) (seconds->local-time))
+(define (get-date-time)
+  (let* ((v (seconds->local-time))
+         (y (vector-ref v 5)))
+    (vector-set! v 5 (+ y 1900))
+    v))
 
 ;; ;; guile, invoke with guile vm.scm ROM ...
 ;; (use-modules (srfi srfi-60) (ice-9 binary-ports))
 ;; (define (open-rom path) (open-input-file path))
 ;; (define (command-line-arguments) (cdr (command-line)))
-;; (define (get-date-time) (localtime (current-time)))
+;; (define (get-date-time)
+;;   (let* ((v (localtime (current-time)))
+;;          (y (vector-ref v 5))
+;;          (tz (vector-ref v 8)))
+;;     (vector-set! v 5 (+ y 1900))
+;;     (vector-set! v 8 (not (= tz 0)))
+;;     v))
 
 ;; ;; chibi scheme, invoke with ???
 ;; (import (scheme base) (scheme bitwise) (scheme file))
@@ -29,6 +39,12 @@
 ;; ;; chez scheme, invoke with chezscheme --script vm.scm ROM ...
 ;; (define (open-rom path) (open-file-input-port path))
 ;; (define (command-line-arguments) (cdr (command-line)))
+;; (define (get-date-time)
+;;   (let ((t (current-date)))
+;;     (vector
+;;      (date-second t) (date-minute t) (date-hour t)
+;;      (date-day t) (date-month t) (date-year t)
+;;      (date-week-day t) (date-year-day t) (date-dst? t))))
 
 ;; === portable scheme code follows
 
@@ -194,20 +210,18 @@
 (define (_datetime field)
   (u8 (let ((t (get-date-time)))
         (cond
-         ((= field 0) (u16->hi (+ 1900 (vector-ref t 5)))) ; year hi
-         ((= field 1) (u16->lo (+ 1900 (vector-ref t 5)))) ; year lo
-         ((= field 2) (vector-ref t 4))                    ; month
-         ((= field 3) (vector-ref t 3))                    ; day of month
-         ((= field 4) (vector-ref t 2))                    ; hours
-         ((= field 5) (vector-ref t 1))                    ; minutes
-         ((= field 6) (vector-ref t 0))                    ; seconds
-         ((= field 7) (vector-ref t 6))                    ; day of week
-         ((= field 8) (u16->hi (vector-ref t 7)))          ; day of year hi
-         ((= field 9) (u16->lo (vector-ref t 7)))          ; day of year lo
-         ((= field 10)
-          (let ((x (vector-ref t 8)))
-            (cond ((not x) 0) ((= x 0) 0) (* 1))))         ; is dst
-         (* (vector-ref dev (+ 192 field)))))))            ; device memory
+         ((= field 0) (u16->hi (vector-ref t 5))) ; year hi
+         ((= field 1) (u16->lo (vector-ref t 5))) ; year lo
+         ((= field 2) (vector-ref t 4))           ; month
+         ((= field 3) (vector-ref t 3))           ; day of month
+         ((= field 4) (vector-ref t 2))           ; hours
+         ((= field 5) (vector-ref t 1))           ; minutes
+         ((= field 6) (vector-ref t 0))           ; seconds
+         ((= field 7) (vector-ref t 6))           ; day of week
+         ((= field 8) (u16->hi (vector-ref t 7))) ; day of year hi
+         ((= field 9) (u16->lo (vector-ref t 7))) ; day of year lo
+         ((= field 10) (if (vector-ref t 8) 1 0)) ; is dst
+         (* (vector-ref dev (+ 192 field)))))))   ; device memory
 
 ;; DEO base instruction implementation
 (define (deo-impl k)
@@ -223,24 +237,24 @@
   (cond
    ((= 4 port) (set-car! wst byte))
    ((= 5 port) (set-car! rst byte))
-   ((= 14 port) (debug))
+   ((= 14 port) (u:debug))
    ((= 24 port) (write-char (integer->char byte) (current-output-port)))
    ((= 25 port) (write-char (integer->char byte) (current-error-port)))
    (* '())))
 
-(define (debug)
-  (debug-stack "WST" wst) (debug-stack "RST" rst))
+(define (u:debug)
+  (u:debug-stack "WST" wst) (u:debug-stack "RST" rst))
 
-(define (debug-stack label st)
+(define (u:debug-stack label st)
   (display label)
-  (debug-cells (cdr st) (u8 (- (car st) 8)) (car st) (current-output-port)))
+  (u:debug-cells (cdr st) (u8 (- (car st) 8)) (car st) (current-output-port)))
 
-(define (debug-cells cells i limit port)
+(define (u:debug-cells cells i limit port)
   (display (if (= i 0) "|" " ") port)
   (if (= i limit) (display "<\n")
       (begin
         (emit-u8 (vector-ref cells i) port)
-        (debug-cells cells (u8 (+ i 1)) limit port))))
+        (u:debug-cells cells (u8 (+ i 1)) limit port))))
 
 (define (emit-u8 n port)
   (display (number->string (quotient n 16) 16) port)
@@ -361,7 +375,7 @@
 (define (u:read-stdin port)
   (let ((c (read-char port)))
     (if (eof-object? c)
-        (u:send-input #\null 4)
+        (u:send-input #\newline 4)
         (begin
           (u:send-input c 1)
           (u:read-stdin port)))))