[Simh] VAX emulation issues on Raspberry Pi
Zane Healy
healyzh at avanthar.com
Mon Jul 30 21:05:14 EDT 2018
Don’t forget SIMH is emulating a lot more than just the CPU, it also has to emulate all the rest of the hardware that makes up a VAX.
My Raspberry Pi 2 clocks in at about 1.6 VUPS, my ESXI host is a i7-3770 CPU @ 3.40GHz (which is starved for RAM), SIMH/VAX on a VM running on it clocks in at about 34.6 VUPS. I have a i5-3470 @ 3.2Ghz and SIMH runs at about 31.6 VUPS. If you have a top of the line, current i7, you might be able to get close to the speed of your VAXstation 4000/96.
I’ve been buying used HP SFF desktop boxes to use as servers, I pick them up used for almost nothing. A few months ago, that i5 cost me $75, I think the i7 was less than $200. Wiped the drive, put Linux on it, and now the SIMH/VAX instance on it provides most of the storage for my VMS Cluster.
Right now most of my VMS environment at home has been replaced by emulation. Once I move PDXVAX off of a VAXstation 4000/60 (it’s my DECnet area router), I’ll be running a fully emulated environment. Honestly it’s something of a relief. Though I am considering looking into running one physical machine as a desktop, booting it into my cluster.
Instead of starting SIMH like this:
$ ./vax < vax.ini
Try:
$ ./vax vax.ini
All my VMS systems are using Telnet right now, as I don’t have any VMS system running a modern version of SSH. I’ve also not managed to get DECwindows to work right with any X-Windows on my current systems (it works fine with my SGI O2). This is one of the reasons I’m considering running a physical VMS system as a desktop.
You bring up a very good point on the licensing though. I’m not sure what to suggest there. :-(
Zane
> On Jul 30, 2018, at 3:57 PM, Jeremy Begg <jeremy at vsm.com.au> wrote:
>
> Hi,
>
> A while ago the power supply in my VAXstation 4000/96 died and rather than
> fix it I decided to move it to a Raspberry Pi 3.
>
> The VAXstation has a 100MHz CPU and the RPi has a 1.2GHz CPU - about 120
> times faster. Yet the performance of SIMH basically sucks, especially when
> logging in to the emulated VAX via SSH.
>
> On the real VAXstation, establishing an SSH sesison was slow -- it would
> take the better part of a minute -- but once established it was very usable
> and quite capable of running a DECterm to an X11 display on a remote PC over
> an SSH tunnel.
>
> On the Raspberry Pi the SSH session establishment takes several minutes and
> trying to run a DECterm is painful to say the least. I was hoping that the
> RPi's much faster CPU would compensate for the emulation overhead,
> particularly on a very CPU-intensive task like SSH session establishment, so
> this result is rather disappointing.
>
> I could perhaps put up with those issues but there two other, more
> fundamental problems when starting the simulation.
>
> The first one is, the emulation can't be started automatically; I have
> to run it interactively in a terminal window. If I try to automate the
> startup using, for example
>
> $ ./vax < vax.ini
>
> the VAX console boot ROM fails a self test and refuses to boot into VMS.
> If I type the commands from vax.ini by hand, it works fine.
>
> A similar issue occurs if I try to load the boot console NVR from a file:
> the VAX console boot ROM fails its self-test and won't boot VMS.
>
> The second problem is that the simulated VAX is *always* a VAXserver 3900.
> Trying to SET CPU MODEL=MicroVAX just doesn't work, so my VAX-VMS licence
> PAK's availability table code don't suit the machine any more.
>
> The SIMH version is currently
>
> MicroVAX 3900 simulator V4.0-0 Beta git commit id: 733ac0d9
>
> I tried downloading the latest from Github (git commit id: 8077d4de) but it
> didn't fix the startup issues so I haven't persisted with it.
>
> Before starting this exercise I had read several reports of people
> successfullly using Raspberry Pi to run an emulated VAX so I have to think
> something is very broken in my RPi environment, but I'm not sure what I
> should be looking for.
>
> FWIW the Raspberry Pi is running
>
> Linux pieric 4.14.52-v7+ #1123 SMP Wed Jun 27 17:35:49 BST 2018 armv7l GNU/Linux
>
> and the file /etc/os-release is:
>
> PRETTY_NAME="Raspbian GNU/Linux 9 (stretch)"
> NAME="Raspbian GNU/Linux"
> VERSION_ID="9"
> VERSION="9 (stretch)"
> ID=raspbian
> ID_LIKE=debian
> HOME_URL="http://www.raspbian.org/"
> SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
> BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"
>
> SIMH was built with "gcc (Raspbian 6.3.0-18+rpi1+deb9u1) 6.3.0 20170516".
> Here is the full SHOW VERSION output:
>
> sim> show version
> MicroVAX 3900 simulator V4.0-0 Beta
> Simulator Framework Capabilities:
> 64b data
> 64b addresses
> Threaded Ethernet Packet transports:PCAP:TAP:NAT:UDP
> Idle/Throttling support is available
> Virtual Hard Disk (VHD) support
> RAW disk and CD/DVD ROM support
> Asynchronous I/O support (Lock free asynchronous event queue)
> Asynchronous Clock support
> FrontPanel API Version 5
> Host Platform:
> Compiler: GCC 6.3.0 20170516
> Simulator Compiled as C arch: ARM (Release Build) on Nov 9 2017 at 08:04:00
> Memory Access: Little Endian
> Memory Pointer Size: 32 bits
> Large File (>2GB) support
> SDL Video support: No Video Support
> RegEx support for EXPECT commands
> OS clock resolution: 1ms
> Time taken by msleep(1): 1ms
> OS: Linux pieric 4.14.52-v7+ #1123 SMP Wed Jun 27 17:35:49 BST 2018 armv7l GNU/Linux
> git commit id: 733ac0d9
>
> The later version (which I'm not running because it didn't fix the startup issues) is:
>
> sim> show version
> MicroVAX 3900 simulator V4.0-0 Current
> Simulator Framework Capabilities:
> 64b data
> 64b addresses
> Threaded Ethernet Packet transports:PCAP:TAP:NAT:UDP
> Idle/Throttling support is available
> Virtual Hard Disk (VHD) support
> RAW disk and CD/DVD ROM support
> Asynchronous I/O support (Lock free asynchronous event queue)
> Asynchronous Clock support
> FrontPanel API Version 12
> Host Platform:
> Compiler: GCC 6.3.0 20170516
> Simulator Compiled as C arch: ARM (Release Build) on Jun 17 2018 at 21:12:47
> Memory Access: Little Endian
> Memory Pointer Size: 32 bits
> Large File (>2GB) support
> SDL Video support: No Video Support
> RegEx support for EXPECT commands
> OS clock resolution: 1ms
> Time taken by msleep(1): 1ms
> OS: Linux pieric 4.14.52-v7+ #1123 SMP Wed Jun 27 17:35:49 BST 2018 armv7l GNU/Linux
> git commit id: 8077d4de
> git commit time: 2018-06-17T08:37:08+02:00
>
>
> Thanks,
>
> Jeremy Begg
>
> +---------------------------------------------------------+
> | VSM Software Services Pty. Ltd. |
> | http://www.vsm.com.au/ |
> |---------------------------------------------------------|
> | P.O.Box 402, Walkerville, | E-Mail: jeremy at vsm.com.au |
> | South Australia 5081 | Phone: +61 8 8221 5188 |
> |---------------------------| Mobile: 0414 422 947 |
> | A.C.N. 068 409 156 | FAX: +61 8 8221 7199 |
> +---------------------------------------------------------+
> _______________________________________________
> Simh mailing list
> Simh at trailing-edge.com
> http://mailman.trailing-edge.com/mailman/listinfo/simh
More information about the Simh
mailing list