Seeking an ECL monitor (preferably for a dimple-top Sun base) and Sun 3 Keyboard and Mouse

Michael Engel engel at
Mon Jan 26 12:27:46 CST 2015

On 26 Jan 2015, at 09:20, Ian Finder <ian.finder at> wrote:

>> Trying to get my 3/50 restored... If anyone has these available I would like to purchase them from you.

Sun type 4 and 5 keyboards work on the 3/50 using an adapter and 
should be a bit easier to find, pinouts (DB15->Mini-Din 8) can be found 
in the Sun HW reference:

Finding a working ECL monitor might in fact be the bigger problem.
I have never tried to run an EIZO6500 or an Atari TT ECL monitor on
my 3/50 and 3/60, but I suspect these might also work, However, they
probably won't be easier to find today than an original Sun ECL monitor.

There might be an option to convert the ECL monitor signal of the 3/50
back to TTL, which will be easier to adapt to a modern monitor. Looking
at the schematics of the Sun 2 video board at bitsavers, page 18 of 19
a TTL-compatible video output (for very early Sun 2 monochrome TTL
monitors) is supported in addition to ECL, selectable by a jumper
(right hand side of the sheet). The conversion from ECL back to TTL
is done by a 10H125 Quad MECL-to-TTL translator chip (U1809, top 
right corner of the sheet):

I checked if this would also be possible on the 3/50 some months ago 
and - if my memory doesn't fail me - my 3/50 board actually had empty
solder pads for a 10H125. The board is currently about 900 km away
from here, so I can't easily check this and I couldn't find a suitable high
resolution photo of the board. However, I think it might be worthwhile
to investigate if the 3/50 can be adapted to use TTL monitors in a
similar way to the Sun 2 video board. Strangely, the Sun 2/50 
schematics on bitsavers don't seem to include the option for a 

The chip is still available from OnSemi, I ordered a couple, but didn't
get to try them so far.

Hope that helps,

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