[Simh] Standalone boot on vax8600?

[Johnny Billquist]

On 2014-07-11 01:08, Mark Pizzolato - Info Comm wrote:
> On Thursday, July 10, 2014 at 3:13 PM, Cory Smelosky wrote:
>> On Thu, 10 Jul 2014, Henry Bent wrote:
>>
>>> Well, that at least did something different.
>>>
>>> sim> boot rq0 /r5:8
>>> Loading boot code from vmb.exe
>>> %BOOT-F-Unexpected Exceptio
>>>
>>> The 8600 simulator always seems to cut off the last character of its
>>> messages, I wonder if that's in any way related to the other console
>>> problems.
>>>
>>
>> 780, 750, and 730 have the same issue...along with not actually booting from
>> the console RL, floppy, et al.
>
> The last character output in a message just prior to executing a HALT instruction is not surprising since the simulator implements a delay (as a number of instructions executed) from when the data is put in the output register prior to generating the completion interrupt/status.  The halt instruction gets executed before the delay number of instructions have completed.  Even if that was 'fixed', nothing operational would change.  The reason the message has been generated will still exist.
>
> As for direct support for booting an OS from the console media, the 8600 supports BOOT CS /R5:xx to boot from the console RL02.  Other than that, VMB.EXE is actually performing the boot operation and I think that when I checked VMB didn't know how to boot from console floppies on a 780, but it can boot from the console TU58 on both the 730 and 750 (BOOT TD /R5:xx).

Well, I used to boot NetBSD on "my" 8650 by direct booting without VMB, 
Here is the COM file:

------------
!
! Load 'boot.' and boot NetBSD.
!
! 'ra' MSCP drive type boot to multi user mode
!
!
SET SNAP ON             ! Enable ERROR_HALT snapshots
SET FBOX OFF            ! System will turn on Fbox
INIT                    ! SRM processor init
UNJAM                   ! UNJAM SBIA's and enable master sbia interrupts
INIT/PAMM               ! INIT physical address memory map
DEPOSIT CSWP 8          ! Turn off the cache - System will enable cache

!DEPOSIT R10 9          ! 'ra' MSCP drive type - uba0 - drive 0
!DEPOSIT R11 0          ! Software boot flags (multi user mode)

DEP R0 11
DEP R1 20006000
DEP R2 2013f468
DEP R3 F                ! Unit number
DEP R4 0

LOAD/START:0 BOOT.      ! Load 'boot.' at memory location 0
START 60                ! Start 'boot.' at the address 60
------------

But note, that is not not through VMB, so any discussions about R5 
previously is not relevant here. Also, the start address is very much 
depending on the actual image loaded.

	Johnny

-- 
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