[Info-vax] Another Alphaserver 1200 memory question

[H Vlems]

According to the Systems&Options guide the AlphaServer 1200 had three
memory options: MS300-BA (64 MB), MS300-DA (256 MB) and the MS300-EA
(512 MB).
Now the -CA code is missing and I wondered whether two 64 MB boards
would make a "mythical" MS300-CA.
When added, SRM reported the two boards as a 32 MB memory option and
that is what VMS also reported.
I had expected to see the experiment fail, unable to complete T24, or
unable to boot, or, since part of the console lives in upper memory, a
spectacular crash when VMS boots.
Who can supply an explanation for displaying only 25% of the installed
memory pair?
Hans