[Info-vax] AlphaServer 1200 memory question

[John Wallace]

On Jan 23, 12:09 pm, H Vlems <hvl... at freenet.de> wrote:
> One AlphaServer 1200 is fitted with 16 memory boards, 128MB per board.
> The system has 2 GB available. The memory is fitted in pairs and you
> can't mix sizes. I ordered additional boards for a few other 1200's
> and I decided to check all my 1200's and Digital Server 5305's for the
> brand and the specifications of the memory boards.
> The system with 2 GB had 1 memory board with a 66 MHz (PC66) sspec
> inside, it was matched with a 100 MHz board of the same brand and size
> on the other riser card. All memory is Micron MT18LSDT1672AG-10EC7
> except one which is MT18LSDT1672AG-662B4.
> The question is: does the single PC66 board slow down the entire
> memory configuration, or was I lucky and the PC66 board just happens
> to run at 100 MHz without generating memory errors?
>
> Side question: did Digital ever publish memory specifications for its
> Alpha's? I know that the Micron memory works, as well as NEC and SEC
> boards but I'd like to know how to select SDRAM from a manufacturer's
> catalogue by specification.
>
> Hans

That kind of info would be somewhere in the specs for the Alpha chips
that came through Digital Semiconductor with the intention of sale
into the merchant semiconductor and motherboard market. You'd probably
have to dig through lots of manuals to find the info though. There
should be specs for EV4 with 2107x chipset and EV5 with 2117x chipset,
but probably not the EV5 chipset used in the PWS family. The Digital
Semiconductor side of the business had gone by the time EV6 came out,
so you'd need a different route for EV6 memory specs.

If your interest is EV4/EV5 era, you might find a "Motherboard Design
Guide" or two from Digital Semiconductor which should have the kind of
info you're looking for in a somewhat more accessible form. They do
exist but a quick look in the usual search engine didn't find any.

Good luck
John