Anyone speak old PC motherboards / ISA buss on "vintage" CNC machines?

I bought a sharp vertical mill with a Prototrak MX2 two axis CNC.  I really dont need CNC but it can operate as a 3 axis DRO - which I like.

Bought from a surplus center with a 30 day warranty however I'm thinking of shipping it back.

Turns out this mid 90s prototrak uses a 486 motherboard and 8" CRT for processing power & display.  CRT never turned on when I got it (smells fried) but I figured I could see about a cheap upgrade.  Digging into it I see a old school 486, no hard drive (it runs off floppy!) with 16 bit ISA buss.  The CNC stuff runs off 2 of the ISA slots and there was a monochrome video card plugged into it.

I bought a vintage $20 VGA card, plugged it into the motherboard & into a LCD vga monitor and - blank screen.  The lcd senses the video (it wakes up), but just stays black.

Next I thought about trying to find a newer motherboard that had PCI & ISA on it - but I'm trying to be cheap.  It will cost time and $$ to ship it back, but if I can get it online for less than it will cost to ship it back..

I can get replacement screens / updates - but those are in the $1000+ range.

What would you do?  Ship it? fix it?  Anyone have a hoard of 90's PC stuff?

Wow. Floppy based software scares me as floppy disks are very delicate. I wonder if you can download an image of what's supposed to be on that floppy? Maybe someone out there has a way to run that image off flash using a slightly more modern computer?

Ahh, looks like you can download the required floppy disk software from ProtoTrak still: https://www.southwesternindustries.com/software/page/prototrak-mx2-cnc-version-610 apologies if you already found that. 720k floppy! Are you sure that's a 486?!

Can you show me the monitor connector and ISA video board?

This stuff is all very rusty in my memory but I have extensive experience repairing computer systems from that era, while in that era. Not CNC computer systems but ISA is ISA.

Keep this conversation public, I am eager to learn more. I have no use for the knowledge but that's never stopped me before.

IIRC you could get ISA connectors on Pentium machines.  Maybe early pentium 2.  Another option would be to see if a PCI version of the hardware is available on eBay and you can get much newer hardware up to at least pentium 4 that still has PCI.  You could also get a chinese 3 axis DRO kit for about what a vintage computer costs.  If for some reason you ever ditched what you have on that machine I'd be interested in it, I like making old E36 M3 work because I'm some sort of masochist probably.

With that being said I'd be willing to bet you have leaky caps all over that old hardware.

It's very difficult to find ISA motherboards these days.  Two years ago I redesigned a piece of laboratory equipment because we could no longer get motherboards that the ISA interface board for the equipment could plug into.  Even if you can get this up and running it's on borrowed time because of that.

If you want to try and get it going start by unplugging everything from the motherboard except the power supply and the video card.  If it boots to the BIOS self test then start adding things (shutting the machine down each time of course) until you find the component that keeps if from booting.

I might have an ISA motherboard or two kicking around.  If it turns out you need one let me know and I'll look.  If you need one and I have one you can have it.

Feeling kinda old right now.

The last PC I actually built for myself looked like that inside.

720k floppies are extremely robust.  Polar opposite of 1.2 meg 5.25".

Pete. (l33t FS) said:

720k floppies are extremely robust.  Polar opposite of 1.2 meg 5.25".

Any magnetic media from that era is on borrowed time, but with an image available for download it's not such a big deal.

I would start by pulling all of the cards, memory ect off of the board.  Then start adding things back one at a time to see if you can get it to boot.

I think you can do a partial controls upgrade to something like this FlashCut Unit. It may cost a little more in the first phase but it runs on standard windows, has good software support and reuses your power supplies, drivers, and motors. I had two machines from them (a decade ago) and had a really good experience with them. 

Thanks all - I'm pretty sure the MB is OK. I can see the floppy boot up and can press buttons on the pendant and it beeps :)

My current issue is that I'm not sure my vintage ISA VGA card I got off ebay works.

MB is USA made 486(!) circa 1993

I pulled out this 8 bit monochrome card (with printer port!)

And put in ths state of the art 16 bit VGA card.

I'm at the point where I dont have another ISA system to test the VGA card (or a monochrome monitor to test the CNC system).

It looks like I can either try to find another ISA VGA card or find a MB with ISA and PCI so I can try a more modern VGA card.

Or try to find a monchrome to VGA adapter?

I have a friend who is both a computer expert and a vintage CNC enthusiast. I'll send him the link to this thread.

I looked at a bunch of used CNC stuff before buying my Bridgeport, and as a result I talked to a few friends who play in that arena.

Every single person I talked to said "Give up on ANY control system that's more than 10-15 years old, all that old crap doesn't work, and if you do get it working you'll be missing the key to program it, and if you do manage to program it, then a few weeks later something unobtainable will break. Just repower the controls on day one and skip a few steps."

I know this isn't helpful here, but figured I'd pass the wisdom along.

Yep - I agree totally.  With money this is totally is fixable, there is tons of support for these - $1K for a plug in LCD monitor, $2K for southwestern to upgrade.

This prototrak stuff was nice that it either worked as a CNC or as a 3 axis DRO with power feed in X & Y (which is what I wanted).

If I opened this up and saw a machine specific CNC board from 1993 I'd pull the plug and ship it back. Instead I see the PC stuff I messed with back in the 90s.  I've long since pitched all my hardware from that era however looking at ebay I should have kept it.  new ISA VGA cards are listed at $800(!)

And besides this 8" CRT monitor looks cool (but smells terrible):

They actually still make 486 computers today- they're all used in POS systems in fast food joints. Since the processors don't need heat sinks and are so efficient, they can be completely sealed in food and healthcare environments.

How clean are the parts? You might want to try removing them and spraying them down with electronics cleaner or rubbing alcohol and a soft brush- It's possible that age has simply oxidized the contacts. Just make sure it dries completely.

The CRT has popped caps.  Thats the whole reason for the tear down, the 8" display doesnt work - it smells like someone let the smoke out.  I just need to source a display solution for the 486 - I'm pretty sure the 486 side works, just cant see anything.

As someone who designed and built ISA cards back in the late 80's for custom machine control, throw it all out.
You can probably keep the axis drives and replace everything else with a raspberry pi or used laptop.

look at this stuff for inspiration: https://www.machinekit.io/

Just a quick follow up. 

I did buy another $20 vga card on ebay and it did the trick

Software is version 1.0 copyright 1992!

May look into integrating a smaller display into the box but can make holes for now. 

Honsch said:

As someone who designed and built ISA cards back in the late 80's for custom machine control, throw it all out.
You can probably keep the axis drives and replace everything else with a raspberry pi or used laptop.

AIUI modern consumer desktop CPUs are not suitable for the kinds of hard real-time tasks needed for controlling things like CNC mills.  Yes, the modern machine is much, much faster than the 486 that came with it, but they don't make the same guarantees about how long it will take to execute instructions.

In reply to codrus (Forum Supporter) :

That doesn't matter.  Anything that uses DRAM can't guarantee execution time.
Running old software on new CPUs will work just fine, especially when the new CPU is 10x faster.

I still do hard real time work on occasion.  It's no different now than it was back then.  So long as your worst-case results are fast enough it's fine.

Hi,

please can you share what graphics card you bought?

I have one but it doesnt show drawings they come up as symbols which looks to be a graphics issue  

thanks

Y'all are spoilt.

I have an MX2 controller and the video card has a tendency to fail. 

Test to make sure its not a problem with the monitor:  1.) Turn off power.   2.) Unplug the the large ~25 pin connector on the back of the monitor.  3.) Turn power back on.  4.) If the monitor is still good then you will see lines accross the screen.

I buy the video boards on ebay:  The board that has worked for me and is the most common is the WINBOND 66855AF 8bit ISA Hercules Graphics card.

Southwest Industries supports even their old systems.  They will not sell you the graphics card though.  They will sell you a whole new control unit.  The new control units have a  USB floppy emulator on them.

Good luck

I have a MX3 CNC system, it is running for the last two decades in my workshop. Suddenly, it is giving me floating point errors about 2-3 times a day. The screen freezes, I have ti restart from scratch. I have notices that at start up there is a memory mismatch, I have changed and added some of the old RAM but it didn't fix.

Anybody has seen that before ?

In reply to Barnille :

If changing the RAM doesn't fix it that suggests a CPU or mainboard problem. You could try writing the memtest86+ image (linux 32bit, if that doesn't work try the v2.0 bootable ISO from the archives section) to a floppy disk and booting from that to confirm that it's not the RAM. The good news is that running these old CNCs is like retro gaming, they're just old PCs so you should be able to swap them out for something compatible from the same era.

Unfortunately there aren't many tools for testing CPU math accuracy - other than a proprietary Dell test suite I've seen, there are some old apps called fputest and paranoia that you'd almost certainly have to custom-compile to run on an old x86 PC.