From caeb237321b45cfb021622e31a733226a3e6961c Mon Sep 17 00:00:00 2001
From: Joshua Bell <inexorabletash@gmail.com>
Date: Sun, 25 Jun 2023 12:06:40 -0700
Subject: [PATCH] The Cricket!: Reset SSC ACIA before probing/setting

... and don't bother saving/restoring registers during install,
as this will only follow a boot or OS restart.

Suggested by @frankmilliron

Also inhibit interrupts in the SET.XXX utilities for good measure.
---
 clocks/cricket/cricket.system.s | 22 ++++++----------------
 clocks/cricket/set.date.s       | 11 +++++++++++
 clocks/cricket/set.datetime.s   | 22 ++++++++++++++++++++++
 clocks/cricket/set.time.s       | 11 +++++++++++
 4 files changed, 50 insertions(+), 16 deletions(-)

diff --git a/clocks/cricket/cricket.system.s b/clocks/cricket/cricket.system.s
index c3d4fad..9154912 100644
--- a/clocks/cricket/cricket.system.s
+++ b/clocks/cricket/cricket.system.s
@@ -77,10 +77,12 @@ ssc_not_found:
 init_ssc:
         php
         sei
-        lda     COMMAND         ; save status of SSC registers
-        sta     saved_command
-        lda     CONTROL
-        sta     saved_control
+
+        ;; Reset SSC
+        sta     KBDSTRB         ; Port 2 DSR line connected to KBDSTRB
+        lda     #0
+        sta     COMMAND
+        sta     CONTROL
 
         ;; Configure SSC
         lda     #%00001011      ; no parity/echo/interrupts, RTS low, DTR low
@@ -114,12 +116,10 @@ digit:  cmp     #HI('0')          ; < '0' ?
         bcc     :-
 
 cricket_found:
-        jsr     restore_cmd_ctl
         plp
         jmp     install_driver
 
 cricket_not_found:
-        jsr     restore_cmd_ctl
         plp
         ;; fall through...
 
@@ -135,16 +135,6 @@ not_found:
 
         sec                     ; failure
         rts
-
-restore_cmd_ctl:
-        lda     saved_control
-        sta     CONTROL
-        lda     saved_command
-        sta     COMMAND
-        rts
-
-saved_command:  .byte   0
-saved_control:  .byte   0
 .endproc
 
         ;; Write byte in A
diff --git a/clocks/cricket/set.date.s b/clocks/cricket/set.date.s
index 99da0ae..883250a 100644
--- a/clocks/cricket/set.date.s
+++ b/clocks/cricket/set.date.s
@@ -21,6 +21,15 @@
 
         jsr     GETLN2
 
+        php
+        sei
+
+        ;; Reset SSC
+        sta     KBDSTRB         ; Port 2 DSR line connected to KBDSTRB
+        lda     #0
+        sta     COMMAND
+        sta     CONTROL
+
         ;; Configure SSC
         lda     #%00001011      ; no parity/echo/interrupts, RTS low, DTR low
         sta     COMMAND
@@ -43,6 +52,8 @@ loop:   lda     INPUT_BUFFER,x
         cmp     #HI(ASCII_CR)
         bne     loop
 
+        plp
+
         rts
 .endproc
 
diff --git a/clocks/cricket/set.datetime.s b/clocks/cricket/set.datetime.s
index c643323..2ec591d 100644
--- a/clocks/cricket/set.datetime.s
+++ b/clocks/cricket/set.datetime.s
@@ -24,6 +24,15 @@
 
         jsr     GETLN2
 
+        php
+        sei
+
+        ;; Reset SSC
+        sta     KBDSTRB         ; Port 2 DSR line connected to KBDSTRB
+        lda     #0
+        sta     COMMAND
+        sta     CONTROL
+
         ;; Configure SSC
         lda     #%00001011      ; no parity/echo/interrupts, RTS low, DTR low
         sta     COMMAND
@@ -46,6 +55,8 @@
         cmp     #HI(ASCII_CR)
         bne     :-
 
+        plp
+
         ;; --------------------------------------------------
         ;; Time
 
@@ -55,6 +66,15 @@
 
         jsr     GETLN2
 
+        php
+        sei
+
+        ;; Reset SSC
+        sta     KBDSTRB         ; Port 2 DSR line connected to KBDSTRB
+        lda     #0
+        sta     COMMAND
+        sta     CONTROL
+
         ;; Configure SSC
         lda     #%00001011      ; no parity/echo/interrupts, RTS low, DTR low
         sta     COMMAND
@@ -77,6 +97,8 @@
         cmp     #HI(ASCII_CR)
         bne     :-
 
+        plp
+
         rts
 .endproc
 
diff --git a/clocks/cricket/set.time.s b/clocks/cricket/set.time.s
index cb7dd3c..f2ca644 100644
--- a/clocks/cricket/set.time.s
+++ b/clocks/cricket/set.time.s
@@ -21,6 +21,15 @@
 
         jsr     GETLN2
 
+        php
+        sei
+
+        ;; Reset SSC
+        sta     KBDSTRB         ; Port 2 DSR line connected to KBDSTRB
+        lda     #0
+        sta     COMMAND
+        sta     CONTROL
+
         ;; Configure SSC
         lda     #%00001011      ; no parity/echo/interrupts, RTS low, DTR low
         sta     COMMAND
@@ -43,6 +52,8 @@ loop:   lda     INPUT_BUFFER,x
         cmp     #HI(ASCII_CR)
         bne     loop
 
+        plp
+
         rts
 .endproc