SSIMP should use 18-bit mapping, not 16, otherwise it will fail on ph…

…ysical hardware.
PDP-10 · Aug 21, 2024 · 82e936b · 82e936b
1 parent 229ef74
commit 82e936b
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/system/imp.369 b/src/system/imp.369
@@ -187,7 +187,8 @@ IF2,IFN IMPIBF&777,.FATAL IMPIBF not on DEC page boundary
 IMPINI:	SETOM IMPUP		;Not up yet,
 	SETOM IMPTCU		; but thinking about it.
 	MOVEI A,IMPIBF_-9.	;DEC page # of IMP buffer page
-	TRO A,%UQ16B\%UQVAL	;Valid mapping, 16 bit device
+IFE SSIMP,TRO A,%UQ16B\%UQVAL	;Valid mapping, 16 bit device (for real imp)
+.ELSE	TRO A,%UQVAL		;Valid mapping, 18 bit device (for ssimp)
 	IOWRI A,UBAPAG+IUIMPG_1	;Set up 1 DEC page of UBA mapping. Note that
 				; the second half of IUIMPG isn't mapped at all
 	CONO PI,NETOFF		;Freeze things while IMP bashing occurs