"sokolov@alpha.CES.CWRU.Edu" "Michael Sokolov" wrote:

>   First of all, the term "console ROM" is not entirely correct. Although
>MicroVAXen don't have a separate console processor, it seems to me that
>MicroVAX CPUs do have a notion of console mode. It is clearly stated in
>technical manuals for all Q-bus MicroVAXen that the ROM on Q-bus MicroVAX
>CPUs consist of two distinct parts: the console code and the VMB. The
>console code is what has some kind of special property, something that
>distinquishes it from any other code that the MicroVAX can execute. My

There is nothing special about the console code itself (except that it executes 
out of ROM at address 0x2xxxxxxx). On most systems the ROM is actually double 
mapped and one of the mappings is in halt-protected space which means that 
pressing the halt button won't halt it (so infinite loops are a bad idea).

>   Regarding the SCSI device support code in VMS/VMB on KA410 and other
>systems, they are COMPLETELY different. This is explained properly in 4
>relevant paragraphs of my lengthy posting. Since apparently many of you
>were unable to find these paragraphs in there, I'm enclosing them at the
>end of this posting. Basically, KA42/41 (VS3100 M30/38/40/48 and MV3100
>M10/10e/20/20e), KA43 (VS3100 M76), and all other systems are designed for
>standard SCSI devices (disks and tapes with CCS). Standard SCSI disks are
>called DKAn and standard SCSI tapes are called MKAn. Note that these names
>are different from DUAn and MUAn (MSCP and TMSCP). There is no attempt to
>present standard SCSI devices as MSCP devices. The DEC-approved version of

The KA410 disks are controlled by a 9224, the tape by a 5380. It so happens that 
the 5380 is a SCSI controller but at the time no DEC VAX had SCSI available. I 
presume that noone realised that SCSI would become what it is today so there was 
no intention of making the console significantly different to that of the 
MicroVAX II - DUA0 and MUA0 devices seems quite reasonable in that light.

Note that the disk and tape controllers share a common data buffer, so they 
cannot both DMA at the same time.

And since I have the uVAX 2000 Tech Manual in front of me at last 
(EK-VTTA-TM.001 BTW) I can finally say that the system module has separate video 
RAM.

The uVAX/VS jumper is detailed on p 3-233. With the module in front of you and 
the BNC connection to the top right, move down from that connection by about 
four chips. Below and to the left should be a jumper (with 3 resistors to the 
left and more chips to the right and going down the right hand edge of the 
board). With the jumper up (towards the BNC you are a VS2000, with the jumper 
down you are a MicroVAX 2000.
 
>  This is right. What we disagree on is what version of TK50. The only
>official word from DEC that I currently have on this is the VS2000 customer
>doc kit. Unfortunately, it is of no help to resolving our dispute, since it
>just says "TK50". However, I know from several sources that the DEC-
>approved version of TK50 for KA410 is TK50Z-Fx. Unlike TK50Z-Gx, which has

The MicroVAX 2000/VAXstation 2000 user manuals warned of terrible consequences 
if you didn't use the correct RD and TK variants with the box (specifically do 
not use the MicroVAX II variants). I don't know whether it actually matters and 
I've never heard of anyone coming to grief by using the wrong sort. Perhaps it 
depends on the rev level and later rev levels can work on either kind of system.
YMMV.

Antonio

Antonio Carlini                            Mail: carlini@marvin.enet.dec.com
DECnet-Plus for OpenVMS Engineering
Digital Equipment Corporation              Worton Grange, Reading, England