Re: [Simh] Problem with MT_ASTLVL on the VAX-11/780

2017-05-17 Thread Paul Koning
> On May 17, 2017, at 8:00 PM, Matt Burke wrote: > > On 18/05/2017 00:18, Johnny Billquist wrote: >> >> Hum. Do I remember wrong? I seem to remember that when you MOVB to a >> register, the value should be sign extended. So not just the low byte >> should have been modified.

Re: [Simh] Problem with MT_ASTLVL on the VAX-11/780

2017-05-17 Thread Johnny Billquist
No. MOVZx is when you don't want to have the value sign extended. Ie. move *zero* extended. Johnny Matt Burke skrev: (18 maj 2017 02:00:21 CEST) >On 18/05/2017 00:18, Johnny Billquist wrote: >> >> Hum. Do I remember wrong? I seem to remember that when you MOVB to a >>

Re: [Simh] Problem with MT_ASTLVL on the VAX-11/780

2017-05-17 Thread Matt Burke
On 18/05/2017 00:18, Johnny Billquist wrote: > > Hum. Do I remember wrong? I seem to remember that when you MOVB to a > register, the value should be sign extended. So not just the low byte > should have been modified. > > Johnny > I think you may be thinking of MOVZBL (and MOVZWL for words).