exxos's Atari, Amiga & retro forum

I've not been doing much retro-computing stuff recently, concentrating more on the railway.

It's been more wiring and installation of point motors mainly, and further refurbishment works on those Lima HST power cars.

The HST pick-up contacts and wheels seemed to get dirty and tarnished just sitting on the track so I ordered finer scale replacements from Peter's Spares. I fitted them this afternoon, after clearing the bench of point motors. Seemingly no real improvement, but with added derailing. The second problem, I discovered, was caused by Peter's Spares making the wheel sets too narrow on the axles, 14.0mm apart rather than 14.4mm, which makes all the difference when going over point work.

With regards to the pick-ups on the axles, a full disassembly, fine sanding of the brass contact springs and the axles helped a bit... Electrolube helped a lot. Using a track rubber to polish the surfaces of the wheels helped a great deal as well.

Anyway, seems as if I may have fixed the problems now, but I'll find out tomorrow after the locos have been sitting there for a while.

P.S. Oh! I now have a date for the installation of my solar panels and battery... 13th January. But that means I need to clear out the loft of all the retro stuff and store it SOMEWHERE. eek!

Not much to report other than "fun" upgrading the OS on my home server.

The "fun" this time was that the X server wouldn't start as I'd set a kernel parameter to not do a modeset for the Intel display adapter due to the text in console mode going tiny (4K monitor). Previously this wasn't a problem as the Intel display driver just overruled it and it worked, but the new Kernel driver just fails. The other "fun" was that my own compiled version of dovecot couldn't find the OpenSSL libraries, but that just needed a recompile and install to fix.

Over all not tooooo much of a pain.

Finally, after well over a year, I tried the DFB1X in my Falcon... The CPU hardly gets warm and the contact with the shield above should be enough of a heatsink.

Unfortunately it will need the Falcon to have the clock patch added so as to be able to use the DSP with it though. The system works well as long as the DSP isn't accessed and Frontier will run forever (though Frontbench won't run, but that's no different to when the DFB1X isn't installed). Using the jumper to disable the card returns the machine to full operation with no issues with the DSP whatsoever.

Loaded EmuTOS into the second ROM bank so as to use Alt-RAM.

Not everything which uses the DSP heavily fails. Both the Joy demo and AceTracker fail when trying to set the display resolution but the 0Three0 demo, which uses the FPU and DSP a lot (from the look of the DFB1X LEDs) works flawlessly, so does "Hmmm" and most other demos. The timing must be very close to working on this machine.

Seeing as the Falcon upgrade is on hold I decided to see if I could refit the original powers supply into the Third Coast Technologies enclosure.

A number of years ago I removed it and replaced the 5V supply with a bring PSU from Maplin to power the SCSI2SD board I was using in it (as the original 27MB Seagate drive had gone to heaven decades ago). The original PSU had died (seemingly).

The Original Astec PSU sat in a cupboard until last year when I refurbished it as practise for the extremely similar Apricot Xi PSU. All it actually needed was new RIFA replacements and some output caps.

Anyway,reusing the original PSU connectors but my redone (and less dangerous) power cabling from the previous Maplin refurb I managed to get it back in.

I'd previously used an old CDROM drive to pull enough current to allow the PSU to power up so did that again and then checked the +5V... 5.8V Eeeek! Quickly powered off. Removed the CDROM drive and then went in search of an old hard drive which would (a) pull enough current, (b) not spin down (or if it did still draw enough current) and (c) be mostly dead.

I tried a few Quantum drives with stuck heads, but they didn't draw enough current and quickly spun down. A Sony drive from an early Mac pulled almost enough but may still have some life in it. In the end I found an early Seagate IDE drive which pulled enough to properly bring the +5V to precisely 5V, even after it spun down after failing to initialise... Both quiet and useful! Not only this but it was in a 5.25" bracket making it simple to screw into the enclosure.

The result...


A happy system.

I'd forgotten just how massive the enclosure is. It's far deeper than a Mega ST.

As I now have a 3D printer I can design a fake 5.25" hard drive facia with a bracket for the SCSI2SD 5.0 board to bolt onto and to fit the 5.25" drive mounting holes in the enclosure.

I may use this with the Atari machines for the 16 bit display later in the year.

Interesting to see that @stephen_usher as I also have an old TCT hard drive (and the PSU in mine 'died' a few years ago).

I replaced the original dead ST251 hard drive with a pair of 80MB Quantum 3.5" drives back in the late 90s & have a replacement PSU to fit at some point, just never quite had the time to get it completed.

Anyway, I will check what the original PSU is labelled as & see if it can be resurrected - I'm sure the RIFA died (given the smell at the time) if only for nostalgic value!

The PSU in mine is an Astec. (Note the manufacture date of 38th week of 1984 even though I bought this in late 1989.)


This is what it looks like inside. A pretty generic Astec design and pretty easy to work on and repair (other than the two nuts and washers holding the heatsink to the frame).

Nice PSU !

You can switch it to 115V.

HigashiJun wrote: 07 Jan 2025 23:27 Nice PSU !

You can switch it to 115V.

Most Astecs can by just moving a jumper wire.

stephen_usher wrote: 08 Jan 2025 00:04 More Astecs can by just moving a jumper wire.

Good to know that !