8 Nov
2014
8 Nov
'14
4:21 p.m.
On 08/11/2014 23:02, Tothwolf wrote:
It would have been hand soldered. Wirewrap pins
can't be wave soldered
since that would contaminate the gold or silver plated pins with solder
(the solder would dissolve and strips the gold or silver from the pin).
The "wirewrap" pins on the 11/23 and many other DEC boards are short
pins that are accessed on the /component/ side of the board and used for
jumper links, eg to select baud rates, or in the case of an 11/23 to set
the boot configuration and other things. See for example the images at
http://store.reuseum.com/DEC_M8186_F11_Fonz_CPU_Processor_Board_Q_Bus_p/000…
There's a group of pins with their jumpers to the right of the middle
40-pin IC. Look carefully and you'll see 5 (IIRC) other pairs,
including one near the top left of the crystal oscillator with a jumper
on it, and one with no jumper to the right of the smaller IC two rows
above the main jumper group. Other DEC boards such as DLV11J and the
notorious (because of gazillions of jumper options) MXV11B do actually
use wirewrap to such pins rather than jumpers, in a few cases 2-level wrap.
--
Pete