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NOVA: Fix carry display in CPU instruction history

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Problem: Currently when viewing the Nova CPU history the carry flag is always
displayed as 0 regardless of it's actual value at the time.

Cause: The carry bit is stored in bit 17 and is lost when stored into the
int16 carry member of struct Hist_entry

Solution: Shift carry into bit 0 before storing it in the CPU history.
Improve code for displaying carry bit.
This commit is contained in:
Samuel Deutsch
2020-10-04 05:51:04 -07:00
committed by Mark Pizzolato
parent aaa4e4ca5e
commit adf1a4c1dc
1 changed files with 4 additions and 3 deletions
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7
NOVA/nova_cpu.c
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@@ -1,6 +1,6 @@
/* nova_cpu.c: NOVA CPU simulator
Copyright (c) 1993-2017, Robert M. Supnik
Copyright (c) 1993-2020, Robert M. Supnik
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
cpu Nova central processor
03-Oct-20 RMS Fixed bug in history handling of C bit (Samuel Deutsch)
07-Sep-17 RMS Fixed sim_eval declaration in history routine (COVERITY)
17-Mar-13 RMS Added clarifying brances to IND_STEP macro (Dave Bryan)
04-Jul-07 BKR DEV_SET/CLR macros now used,
@@ -1316,7 +1317,7 @@ if ( hist )
hist_ptr->ac1 = AC[ 1 ] ;
hist_ptr->ac2 = AC[ 2 ] ;
hist_ptr->ac3 = AC[ 3 ] ;
hist_ptr->carry = C ;
hist_ptr->carry = C >> 16 ;
hist_ptr->fp = FP ;
hist_ptr->sp = SP ;
hist_ptr->devBusy = dev_busy ;
@@ -1388,7 +1389,7 @@ if ( hptr )
(hptr->ac1 & 0xFFFF),
(hptr->ac2 & 0xFFFF),
(hptr->ac3 & 0xFFFF),
((hptr->carry) ? 1 : 0)
(hptr->carry & 1)
) ;
if ( cpu_unit.flags & UNIT_STK /* Nova 3 or Nova 4 */ )
{