Possible sale of 2 xShort ST STM 520 4MB with ST536 built in

[Steve]

@PhilC

[PhilC]

How did you get over the pins being in the wrong place?

I think I had to desolder the header on the CF card and resolder them on the underside too.

Ok thanks Steve, will check the vid

Edit have checked the video and I'll need some CFcard adaptors with through hole headers, not end soldered like the ones I have, so will order some.

[PhilC]

Well that's another ST536 built, this time with the header pins for the IDE on the bottom and I've got an expensive IDE CF adaptor coming tomorrow, followed by some cheap ones from China, whenever they get here.

PXL_20250227_144839194.jpg (318.87 KiB) Viewed 110 times

Got enough parts for 2 more ST536s but that's the lot after that.

[PhilC]

P.S. Maximum points if you saw I put the one of the buffer chips the wrong way round. I only noticed when I put my glasses back on.

[mrbombermillzy]

Good work Phil. (except the buffer, eh? )

So do all those 33Mhz PGA 030s manage 50Mhz?

[PhilC]

Good work Phil. (except the buffer, eh? )

So do all those 33Mhz PGA 030s manage 50Mhz?

I probably have 3 or 4 more plastic cpus that will do 50mhz and then around 20 that won't. It's really pot luck these days, especially with the remarking of cpus

[coonsgm]

Yeah for my short ST I followed what @coonsgm did and soldered the IDE header on the bottom.

How did you get over the pins being in the wrong place?

What I did is also modify the CF card adapter pinout by desoldering the headers and flipping them around too

I did a whole mess of mapping the pins in excel to make sure it would work....and work it does!

[PhilC]

Thanks @coonsgm.

I've also looked at this from a mechanical point of view. To get the case closed we needed to lose height on the ST536 so I've done the following.

Remove the plastic spacer on the IDE header so that the plug will fit flush to the board.

PXL_20250228_203339339.jpg (307.54 KiB) Viewed 46 times

Trim the floppy drive port as there's a lot of plastic on this adding to the overall height of the port internally. It was fouling on a few of the SMT resistors at the back of the board, hence the chamfered edges.

PXL_20250228_203132152.jpg (260.51 KiB) Viewed 46 times

Fit two rows of female headers

1740774992888527149548534921210.jpg (239.89 KiB) Viewed 46 times

Fit ST536, it does sit at an angle but is tight in the socket and no longer fouls the IDE plug and the keyboard now sits where it should.

PXL_20250228_203058290.jpg (384.52 KiB) Viewed 46 times

I'll give it a good test tomorrow and tidy up the floppy port a little.

[exxos]

@PhilC can't tell exactly, but if I moved the IDE connector backwards, if its moved to far, will the solder joins on the bottom of the board end up touch one of the MB's rear IO connectors or something ?

[PhilC]

@exxos Heres with the standard method with IDE as @coonsgm and @Steve had put it.

PXL_20250228_210232484.jpg (412.98 KiB) Viewed 38 times

And here's the lower one with the floppy port mod.

PXL_20250228_210219924.jpg (375.99 KiB) Viewed 38 times