19 Sep
2026
19 Sep
'26
10:20 p.m.
On Sat, Sep 19, 2026, 10:03 PM Mike Katz via cctalk <cctalk(a)classiccmp.org
wrote:
Glen,
I'm hoping to purchase two 16557Ds to upgrade the two 16550As that I
have. How do the 16557D's connect to each other or do they not need to
connect together?
The 16554/5/6/7 modules have a 20 conductor cable plugged between two
connectors on a single module configuration. On a multiple module
configuration one end of the cable is unplugged from one of the connectors
on each of the expander boards and plugged into a different connector on
the master board.
Also, an additional pair of cables is needed to connect between a pair of
connectors on each board of a multiple board set.
HP part number 16555-68701 or 16555-68705 is a set of pairs of cables for
different numbers of boards in the set. 16555 are limited to 3 board sets,
16556/7 up to 5 board sets.
For example item 263655364718 or 355859408593 on eBay.