exxos's Atari, Amiga & retro forum

Today I picked up the machines I'd rescued from the work scrapheap:


A couple of LCD screens which should hopefully do 15KHz refresh, some AT keyboards, one in its original box, a Sun Ultra 45 and an old 486 PC, which I snipped the VARTA (destroyer of motherboards) out of. The VARTA had only just started to leak so the M/B is fine. The M/B also has an IBM PC-AT compatible "external battery" header so no need to hack anything.

Unfortunately the PSU on the 486 was a bit unwell. It would power the machine up sometimes but not every time, so before I moved the machines I took the PSU out, I then moved everything but the PSU into my storage unit.

To cut a long story short, I had in stock all the major capacitors so I swapped the twin 2200uF, 1000uf and 470uF caps and tested with some hard drives as the load and it looks OK now. The ground planes were awful. The Hakko took a few seconds to melt the solder but my 70w iron had huge difficulty.


So, tomorrow evening I think I'll bring the machine back from the storage and see if I can get the two had drives to work. The 1991 vintage BIOS seems to have a hard disk detect utility built in so it may be bale to set the drive types correctly.

Very nice haul. 😁

Nice little colle tonight there @stephen_usher , especially getting that ultra 45.

Managed to get the 486 to boot eventually, once I'd determined the disk parameters, how the IDE cable went and turned off the external cache memory.

I wonder if this motherboard is one with fake cache or it's just gone bad.

Both hard disks work, amazingly.

The 486 needs more Doom :)

The config.sys has a menu entry for setting up for Doom, though it's not on either disk.

The motherboard is a strange one. From the BIOS identifier it's made by "Lucky Star", it has no silk screen printing giving anything identifying other than "486 Local Bus Ver1.0". There's no information about this board on-line and everyone I've asked is stumped, so there's no way of determining the correct jumper settings for changing things such as cache size.

From the chip date codes it looks like the machine was from mid 1992.


Those aren't VESA local bus connectors, they're a pre-VESA one, possibly Omni Local Bus.

Other than that I've lashed together a BIOS battery, and that seems to be all working. CheckIt verifies the hardware.

From the filesystem it looks like the last time the machine was used was 1999.

rubber_jonnie wrote: 06 Jan 2022 23:06 The 486 needs more Doom :)

You wanted Doom, so here's Doom...

stephen_usher wrote: 08 Jan 2022 12:51

rubber_jonnie wrote: 06 Jan 2022 23:06 The 486 needs more Doom :)

You wanted Doom, so here's Doom...

Splendid!! Still a favourite of mine even after all these years!!

Nice bit of archeology on the machine too. That bus is really weird, I haven't seen one like that and definitely not VLB.

I always thought you were supposed to dodge the fireballs

Tell that to the demo authors :-)