folkert/simh-testsetgenerator
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

HP3000: Bug fix for byte instruction effective addresses calculations with negative indexes.

Browse source 
Update from Dave Bryan
This commit is contained in:
Mark Pizzolato 2016-03-12 08:04:44 -08:00
parent 1b6f28a743
commit b304d7f4a8
1 changed files with 3 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
HP3000/hp3000_cpu.c
View file

@ -25,6 +25,7 @@
CPU HP 3000 Series III Central Processing Unit
11-Mar-16 JDB Fixed byte EA calculations with negative indexes
22-Dec-15 JDB First release version
01-Apr-15 JDB First successful run of MPE-V/R through account login
11-Dec-12 JDB Created
@ -2457,10 +2458,10 @@ else { /* otherwise the mod
if ((CIR & LSDX_MASK) == LDD_X /* if the mode */
|| (CIR & LSDX_MASK) == STD_X) /* is double-word indexed */
displacement = displacement + X * 2; /* then add the doubled index to the displacement */
displacement = displacement + X * 2 & DV_MASK; /* then add the doubled index to the displacement */
else if (mode_disp & X_FLAG) /* otherwise if the mode is indexed */
displacement = displacement + X; /* then add the index to the displacement */
displacement = displacement + X & DV_MASK; /* then add the index to the displacement */
if (selector == NULL) /* if a word address is requested */
base = base + displacement; /* then add in the word displacement */