Altair, IMSAI, SWTPC, etc. for sale in Philly

[Geoffrey Reed]

On 11/4/16, 7:22 AM, "cctalk on behalf of Paul Koning"
<cctalk-bounces at classiccmp.org on behalf of paulkoning at comcast.net> wrote:

>
>> On Nov 4, 2016, at 9:19 AM, Sam O'nella <barythrin at gmail.com> wrote:
>> 
>> Out of curiosity and ignorance what's with the solder joints on the
>>cards in the pictures? That orange color seems like it's everywhere
>>around cold looking solder joints.  Is that rust, some sort or
>>protection, or acid corrosion?...
>> 
>>> The Altair 8800, a very early one, 4-slot motherboard, 1K ram, ceramic
>>>CPU,
>>> you will see: https://goo.gl/photos/3C1pzfwFoZ3koPgt9
>
>I doubt it's any of those.  That's the typical look of a board
>hand-soldered with conventional rosin core solder.  While it's possible
>to remove that flux (thought I think the best solvents are non-PC), it is
>often omitted and generally not needed.
>
>	paul
>
>

Yes, looking at those pictures that¹s rosin.