[Simh] VAX emulator slow to configure extra disks

[Johnny Billquist]

I can't remember having any such issues, but then again I also can't 
remember if I ever tried it with VAX. With PDP-11 it works without any 
issues.

This is, though, another slight silliness in simh. The limit to 4 disks 
per controller is very artificial. The UDA50, KDA50, and maybe some 
other controllers only have four actual, physical ports, which limited 
them to only have four disks per controller. However, MSCP itself do not 
have such a limitation, and common SCSI controllers for these machines 
which use MSCP allows more than four disks on a controller, and most 
software (at least RSX and VMS) also do not limit themselves to only 
configure max four disks on a controller. I wish simh didn't put such 
arbitrary limitations in. simh also decides on unit numbers by itself, 
which could also have been nice to be able to choose.

   Johnny

On 2019-06-23 15:37, Jonathan Welch wrote:
> A vax emulator I was configuring for a friend (MicroVAX 3900 simulator
> V4.0-0 Current git commit id: ab3e07a4) needs to mount more than four
> disks.
> 
> The .INI file has
> set rqb enabled
> 
> and an associated attach command.
> 
> In my VMS startup disks are mounted very close to the beginning of the
> boot sequence.
> 
> I discovered that when the emulator starts it is necessary to put a
> $ WAIT 00:00:06
> before mounting DUB0; the wait is necessary for the disk to appear.
> 
> Is this something that is expected behavior and should be documented
> or a bug that can be fixed?
> _______________________________________________
> Simh mailing list
> Simh at trailing-edge.com
> http://mailman.trailing-edge.com/mailman/listinfo/simh
> 

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol