Connecting a SunBlade 100 to an old monitor

This describes a short converter cable I made to connect a new SunBlade 100 which has a PC style video output to an old Sun (Sony) monitor (GDM-1662B) of a similar vintage (DEC 1991) to my IPC. The official Sun documentation suggests that this cannot be done. The empirical evidence suggests otherwise.

I must point out that this is not a project to be undertaken lightly. Soldering to the 15 way micro-D connectors requires a certain amount of dexterity, and also some fine co-axial cable. At the other end the 13w3 connectors typically have crimped coax connectors - requiring a special tool. The alternative I opted for was to canibalise an existing 13w3 connector that I no longer needed.

Pinouts

This shows the front and back of a 15 way micro-D connector. These have been used on PCs for years for video connection to the monitor. The SunBlade 100 is in essence a SPARC powered PC complete with ATI chipset an PC style video output. Both front and back of the connector are shown to avoid any mixups when soldering to the back and the pins are numbered from right to left.

This diagram shows the front and back of a male 13w3 connector that plugs into the back of an old Sun monitor. This is really a 25 way D-type with 15 of the pins removed to make room for the 3 coax connectors. Again, both sides are shown.

Connections

The following connections are made with small 50 ohm co-axial cable. Keep the joints as neat and small as reasonably possible to prevent impedance problems and consequent ghosting on the display.

Signal 15w micro-D 13w3
Red Signal 1 A1
Ground 6
Green Signal 2 A2
Ground 7
Blue Signal 3 A3
Ground 8

Given the short length of the cable, the following can be hooked up with ribbon cable for simplicity. Keep the GND as one of the middle wires though. I'd suggest soldering to the remaining middle pins of the 15 way micro-D first as they will be difficult to reach later. No connection is made to pins 9, 14, and 15 of the 15 way micro-D, or to pins 2 and 6 on the 13w3 connector.

Signal 15w micro-D 13w3
ID2 4 3
GND 5, 10 1, 4, 7, 10
N/C 9 N/C
ID0 11 9
ID1 12 8
HSync/CSync 13 5
VSync 14 N/C
ID3 15 N/C

Notes

A similar approach may work with other new Sun boxes and other old fixed-frequency monitors. I don't have the equipment to test the idea out.

If the power management features are set to turn off the display when the machine is unused for a period of time, then all the output to the monitor is cut off. These old monitors don't recognise any energy saving mode, and while the display does go blank, they continue to draw plenty of power. Its not clear whether this might, in time, damage the monitor.

I found that the 13w3 connector would not fit into a number of 25 way D-type shells I had. The crimped coax connectors would foul on the tapering case or on moulded fixings in the shell. Something to bear in mind if you are ordering new components.

I do not accept any responsibility for the use or misuse of these ideas and designs. Anyone may hand-build or adapt the design for private use. I would appreciate a quick e-mail or feedback if you have used or improved on the design.