NS6316 - 16MB Memory board for the MicroVAX II

[Alegend]

Hi All,

I have two NS6316 boards, which are 16MB memory boards for the KA630. But I cannot make them work as 16MB.
I could find no documentation, other than a reference here, which shows usage of a (now extinct?) National Semiconductor memory diagnostics software from 1986.
There is an installation guide but for the NS638, which is a 8MB board.

The TMS4C1024 ICs are 1Mbit, and since there are 144 + 1 (spare?) of them, it certainly looks like a 16MB board.
What I get:
- The front toggle switch switches the whole board on or off - this works fine.
- The only jumper on the board is W1/W2. With W1 inserted, VMS boots to 4MB. With W2 inserted, it sees 8MB.

That's it, there are no more jumpers to play with, and I can't figure out how 16MB is possible.
The test setup is a minimal KA630, NS6316, and a UC07 SCSI controller.
Any ideas will be most welcome.
-Alon.
Micro

 

[gslick]

What exactly do you mean by "With W1 inserted, VMS boots to 4MB. With W2 inserted, it sees 8MB."

Are you just going by what SHOW MEMORY displays in VMS?

Did you do a fresh install of VMS yourself on the system with the 16MB board already installed, or are you running a previous installation of VMS, that might have been installed when there was less memory in the system?

If I remember correctly how this works, SHOW MEMORY in VMS displays the amount of memory that the system is currently configured to use, which may be less than the amount of the physical memory that is currently present in the system. During installation, the parameters are auto-sized based on the amount of physical memory in the system, but the parameters are not auto-sized on every boot if the amount of physical memory installed in the system increases.

If the current VMS installation was installed when there was less physical memory present in the system, you might need to go through the @SYS$UPDATE:AUTOGEN process to increase the size of the System Page, Swap, and Dump Files to utilize all of the physical memory.

It's been a while since I have gone through that. I forget all of the details.

 

[Alegend]

What exactly do you mean by "With W1 inserted, VMS boots to 4MB. With W2 inserted, it sees 8MB."

I am going through the @SYS$UPDATE:AUTOGEN... and the system image to start with was set up on a 16MB system.

 

[Alegend]

Update: I have checked the obvious missing configuration, which is to remove the jumper from W1/W2 completely.
No luck.
Double checked with AUTOGEN, SH MEM, SH MEM/PHY and a few cut fingers:
W1 shorted - 5MB
W2 shorted - 8MB
No jumper at all - 9MB

I have also replaced the KA630 CPU, in case something weird happened and it does not like 16MB. Still no luck.
I have verified that the procedure for making VMS recognize the presence of additional memory actually works.

$MC SYSGEN
USE CURRENT
SET PHYSICALPAGES 32768
WRITE CURRENT
EXIT
$@SYS$UPDATE:AUTOGEN GETDATA GENPARAMS

For example, adding a 4MB board to the system with a NS6316 configured as 9MB, I can sucessfully make VMS see 13MB.

I'll leave it here, thanks gslick for the input, perhaps sometime in the future someone comes up with a solution, an explanation, or the manual.
-Alon.

 

[gslick]

Update: I have checked the obvious missing configuration, which is to remove the jumper from W1/W2 completely.
No luck.
Double checked with AUTOGEN, SH MEM, SH MEM/PHY and a few cut fingers:
W1 shorted - 5MB
W2 shorted - 8MB
No jumper at all - 9MB

The M7608 KA630 CPU board has 1MB of RAM on board, so system RAM totals of 5MB or 9MB make some sense if the NS6316 board is configured for 4MB or 8MB itself.

A system RAM total of 8MB seems a bit weird, 1MB on the KA630 CPU board plus 7MB on the NS6316 board?

The NS638 installation guide you referenced above notes that the 1MB of RAM on the KA630 CPU board is disabled when the NS638 boards are configured for 16MB of system RAM.

http://www.bitsavers.org/components...roVAX_ll_Memory_Module_Installation_Guide.pdf

Maybe that is also happening with a jumper configuration on the NS6316 to get 8MB of total system RAM instead of 9MB total, but no idea why it wouldn't be the full 16MB instead.

Also, I wonder why there is a need for the jumper on the NS638 boards for 16MB of system RAM. There aren't any similar configuration jumpers on the DEC M7609 8MB boards.

 

[Alegend]

The NS638 manual (page 3) states that shorting W2 is necessary when the system has less than 16MB, and shorting W1 should be done when there are 16MB.
The diagonstics software document says "The NS6316 can be configured as either a 4-, 8- or 16-MByte unit."

So perhaps the jumper position "W2 shorted" on the NS6316 simply does a "disable KA630 internal 1MB RAM", something that happens automagically when two M7609 (8MB) are installed.

The NS6316 is behaving almost as expected - it can do 4MB (resulting in 5MB total), it can do 8MB (resulting in 9MB total), but for some reason its "16MB" results in 8MB - the KA630 1MB RAM is indeed disabled, but an additional 8MB is missing...