23 Oct
2020
23 Oct
'20
10:57 a.m.
On Wed, Oct 21, 2020 at 6:22 AM Pontus Pihlgren via cctalk <
cctalk at classiccmp.org> wrote:
On Tue, Oct 20, 2020 at 11:26:22PM -0400, Chris Zach
via cctalk wrote:
I have seen PDP-15 core memory and it is not that format. It looks like
the memory modules from a PDP-8/I or -8/L
The ME15 memory for the PDP-15 used that kind of memory, but it normally
used an 18-bit H215. I think there was another variant that offered parity
that would have used the 19-bit H216.
There might have been PDP-15 memory earlier than the ME15, but at the time
of the PDP-15 introduction (1970), H21x core planes were used in most DEC
machines, so it would have been surprising for them to use something else.
Perhaps some PDP-15 systems were upgrades from the PDP-9, which used memory
modules similar to the PDP-8/I.
Or maybe
a PDP-15? 18 bits plus parity.
Possible, did the pdp15 use that type of board?