WattsUp: It Lives!

Stage 1 success – using the NV1 PSU, with a considerably new PSU wiring loom, the SPARCstation-10 powers-up and initialises, ready to boot!
As can be seen from the graphics screen, it’s running happily: living2

Yay! You know, this project might actually lead somewhere…

It seems OK with a pair of 60 MHz SuperSPARC CPUs, a single memory DIMM, a couple of SCSI cards and a basic GX LEGO (“Low-End Graphics Option”) graphics card. There is still a lot left to do (mounting the PSU in a drive-bay, fitting a PSU fan, restoring the main chassis fans, and so on and so on), but I’m feeling much happier now – I thought for a while that it just wasn’t going to work at all.

The new cable-loom has a little trick in it: the sense wires are the thin twisted-pair wires that can be seen in the picture. The +ve and -ve sense lines should be twisted together so that any electrical/magnetic interference effects both lines the same way, thus preserving the actual differential signal level.

The sense lines I used are much thinner (AWG-24) than the power-lines, so that they have more resistance, thus persuading the PSU to boost output voltage level a little more than usual – the SS10 nominally requires 5.1V, not 5.0V.

As this is the “spare” SS10, I don’t have an available disk drive with an operating-system already installed, so the next job will be to try and install an OS before the PSU overheats – there are no fans attached yet!

PS: Bonus points available to anyone who can identify a little problem with this SS10 itself, due to it having been in storage for a long time…

3 thoughts on “WattsUp: It Lives!

  1. Excellent work! I hope I never need to build a supply for my machine, but if I had to I could do something similar.

    I’d say that the problem with you ss-10 is probably going to be a flat PROM battery. I’m not sure how easy it is to replace those as I haven’t had to do it yet.


    1. You spotted it – NVRAM chip battery is dead. In my primary SS10 I fixed that by carving the end off the chip and wiring the battery compartment of an old Sun microphone to it – now running off a *replaceable* CR2032 button-cell! That is quite a bit of work tho. This time I’ll settle for just replacing the chip…

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s