Strange i-con Unibus (?) board

[Eric Smith]

On Tue, Dec 9, 2014 at 2:01 AM, Pete Turnbull <pete at dunnington.plus.com> wrote:
> Maybe, but SIPPs (as I've usually seen them called, to distinguish them from
> SIPs: see below) are just SIMMs that have pins.

Though technically SIP is the correct term. I think you're making a distinction
between a SIP IC and a SIP module, but both are correctly called SIP
(Single Inline Package).

> There's also a once-common type of chip - most commonly memory chips - that
> are SIP (not SIPP) packages as opposed to DIP packages.  I have a few
> machines that use those, too.

I haven't seen those, but there was a brief period where RAM chips commonly
had a SIP-like package with the leads formed in a staggered dual row arrangement
extending from one side of the package body and in the plane of the body, known
as a ZIP (Zigzag Inline Package):

    http://upload.wikimedia.org/wikipedia/commons/1/18/ZIP19%2820%29_Toshiba_DRAM_514256.jpg

However, the ZIP package didn't survive long in the market because SIP
modules then SIMM and DIMM modules had lower overall manufacturing cost
due to the reduced overall pin count compared to socketing individual RAM chips.