From 340f43103a0fa81589c1ff1b82604721c60d547b Mon Sep 17 00:00:00 2001
From: Byron Lathi <bslathi19@gmail.com>
Date: Mon, 14 Mar 2022 22:19:19 -0500
Subject: [PATCH] Fix bug where A was overwritten in _uart_txb_block

If you wanted to transmit a value and then check what it was, you can do
that now.
---
 sw/uart.s | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sw/uart.s b/sw/uart.s
index dd23778..c852f7e 100644
--- a/sw/uart.s
+++ b/sw/uart.s
@@ -17,10 +17,12 @@ _uart_txb:
         rts
 
 _uart_txb_block:
+        pha
         sta UART_TXB        ; Write value
 @1:     lda UART_STATUS     ; Wait for status[0] to be 0
         bit #$01
         bne @1
+        pla
         rts
 
 _uart_rxb: