[Simh] Alpha emulator

[Brian Wheeler]

I think you've got the sign bits for displacements backwards in
alpha_defs.h:

#define SIGN_BDSP       0x008000
#define SIGN_MDSP       0x100000

Should probably be

#define SIGN_BDSP       0x100000
#define SIGN_MDSP       0x008000

Since the branch displacements are 21 bits and memory displacements are
16.

Brian


On Tue, 2006-11-07 at 21:06 +0000, bsupnik at comcast.net wrote:
> I thought I had sent this to the mailing list.
> 
> The current Alpha CPU sources are available at
> 
> http://simh.trailing-edge.com/sources/alpha_cpu.zip
> 
> /Bob Supnik
> 
>  -------------- Original message ----------------------
> From: Brian Wheeler <bdwheele at indiana.edu>
> > [I sent this earlier, but I don't know if it got lost in the shuffle]
> > 
> > Is the source for this going to be available for those of us who like to
> > tinker? 
> > 
> > Brian
> > 
> > On Tue, 2006-10-31 at 18:13 +0000, bsupnik at comcast.net wrote:
> > > There's a complete Alpha CPU emulator for SimH, and has been for some time.  
> > It models an EV-56 at the hardware level and should be able to run 
> > PALcode/firmware images.
> > > 
> > > That said, there's no system behind it, and I don't have the time to write 
> > one.  Even the simplest EV-56 system (like the 500au workstation) requires 
> > emulation of the system glue chip, the PCI bus, various PCI peripherals, and 
> > possibly graphics: so as a minimum, the Pyxis chip, the ISP SCSI adapter, the 
> > 21040 Ethernet adapter, a graphics adapter, and the usual complement of PC cruft 
> > (keyboard, mouse, floppy, timers, etc).
> > > 
> > > /Bob Supnik
> > > _______________________________________________
> > > Simh mailing list
> > > Simh at trailing-edge.com
> > > http://mailman.trailing-edge.com/mailman/listinfo/simh
> > 
>