From f3af088deabc1c3f90d22c43dcda9c5b8344bc86 Mon Sep 17 00:00:00 2001
From: "B. Watson" <urchlay@slackware.uk>
Date: Thu, 9 Apr 2026 06:19:28 -0400
Subject: Rewrite the guts of print_ping_time() yet again. 7593 bytes free.

---
 src/irc.c    | 13 +++----------
 src/jifsec.s | 24 +++++++++++++++++++++++-
 2 files changed, 26 insertions(+), 11 deletions(-)

(limited to 'src')

diff --git a/src/irc.c b/src/irc.c
index d052937..14bef03 100644
--- a/src/irc.c
+++ b/src/irc.c
@@ -107,7 +107,7 @@ static void do_priv_nick(void) {
 	}
 }
 
-/* this ping calculation relies on the assumption that
+/* the ping calculation in jifsec.s relies on the assumption that
    nobody's ping time will ever be more than 9 minutes. anyone
    that lagged will have been disconnected from the server already.
    if this assumption turns out to be false, the ping time displayed
@@ -119,19 +119,12 @@ static void do_priv_nick(void) {
    the compiled code smaller, but it grew by ~50 bytes. avoid.
  */
 static void print_ping_time(char *p) {
-	extern void print_jif_sec(unsigned int j);
-	static unsigned int now, pingtime;
-
-	now = read_rtclok();
-	pingtime = (unsigned int)a2uint(p);
-
-	/* correct for rtclock rollover (every ~9 mins) */
-	if(now < pingtime) now |= 0x8000;
+	extern void calc_ping_time(unsigned int j);
 
 	scr_print_active("*** ");
 	scr_print_active(msg_src);
 	scr_print_active(" lag: ");
-	print_jif_sec(now - pingtime);
+	calc_ping_time(p);
 	scr_putc_active('s');
 }
 
diff --git a/src/jifsec.s b/src/jifsec.s
index 4f3d3c8..15ae972 100644
--- a/src/jifsec.s
+++ b/src/jifsec.s
@@ -15,10 +15,32 @@
  _hz = $f0 ; must agree with timers.h!
 
  .import _scr_act_printnum, _scr_putc_active
+ .import _read_rtclok, _a2uint
  .import mulax10
 
  ; extern void print_jif_sec(unsigned int jiffies);
- .export _print_jif_sec
+ .export _print_jif_sec, _calc_ping_time
+
+_calc_ping_time:
+ jsr _a2uint
+ sta acc16
+ stx acc16+1 ; acc16 = timestamp in ping response
+ jsr _read_rtclok ; A/X = low 15 bits of RTCLOK
+ cpx acc16+1 ; has RTCLOK rolled over?
+ bcs @clok_ok
+ pha
+ txa
+ ora #$80
+ tax
+ pla
+@clok_ok:
+ sec
+ sbc acc16
+ pha
+ txa
+ sbc acc16+1
+ tax
+ pla ; A/X now holds "now" minus timestamp
 
 _print_jif_sec:
  jsr divbyhz
-- 
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