[md63825]

Anyone know a good resource for an older ISA Half-Size Motherboard? I may need one if i can't get the one on my '00 EZ Trak to come online. Replaced RTC and now I've got nothing. Even if I get this one back up and going, I figured it would be a good idea to have a backup. This board is in a CIB and the part number is SBC-8251. This board must have been a replacement at some point for this machine in its life because I found a manual for a Rocky 518HV Ver. 4.X Pentium Half-Sized Single Board Computer with other documents in the cabinet. Found a few on good'ole Ebay but most are China sellers. Best I can determine, these boards are ISA 586DX series.

[underthetire]

Those years had counterfeit caps, a lot of computers did. If your good at soldering, id check those. See if they are puffed up. Fixed several hurco motherboards and one romi doing that. Like 6.00 in parts.

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[forhire]

When my SBC stopped working on my TC3 I replaced it with an Advantec PCA-6742 off ebay as re-capping didn't fix mine. Unfortunately the 6742 lacked a floppy interface. This wasn't an issue as I simply got USB working in DOS. I later decided to get the floppy working and purchased a PCA-6743 directly from Advantec. The PCA-6743 supports compact flash which allowed me to added a 2 gig compact flash so I can DNC large files. I later networked it. I have pictures and details here: New (to me) VMC

Turned out the floppy was bad on my machine an likely contributed to my original board failure. Make sure you unplug your floppy drive and see if the board will post.

You can get a few different models from Advantec. ISA Half-Size SBC - Advantech Make sure you check the specs carefully as you don't want to be missing the floppy drive like me. If I recall buying direct from Advantec was about $200 or $250 and they had it to me quick.

If you search ebay for Advantec ISA SBC you'll normally come up with a lot of options.

Yikes... I just searched ebay for PCA-6743 and they are crazy over priced ($350-$500 from China). You can order it direct from Advantec here for $250 with a 2 year warranty.
Ultra low power, fanless DM&P Vortex86DX

[reabdet21]

The 2000 mill has a "disk on a chip" so if you don't find a similar one with that feature, you will need to install a HD or a solid state drive into the drive slot.

[md63825]

Thanks to both. reabdet21, machine has the original HDD but my plan is to install a DOM. I've got these on my other machines also. forhire, I saw that SBC from Advantec and that's likely the route I'll go. I'm a tight wad and thought I'd find something cheaper. Two year warranty looks good. I haven't had a chance to look at the specs on this board but I hope I can adjust the clock speed. I've been told in the past that too fast can cause communication issues with BMDC. Bought two EZ Traks, A 3-axis and a 2-axis. They'd been setting for years at Tulsa Tech. I've only had a chance to work my way thru the 2-axis so far. Both were wired for 480V. Once I got the wiring changed over to 230V, the 2-axis fired up but I got the CMOS battery failure. Use default BIOS and machine homes good and everything runs good. Thought the RTC would have been a simple fix but got the wrong guy to replace it for me. BTW, I looked at your New (to me) VMC thread and I'm super impressed. I've got a Torq-Cut 22. I'm kind of hooked on these Bridgeport machines. I've also got an EZ Path lathe. Not the greatest machines but they do the job and easy to work on.

[forhire]

I haven't had a chance to look at the specs on this board but I hope I can adjust the clock speed. I've been told in the past that too fast can cause communication issues with BMDC.

I had also heard similar concerns but I haven't had any issues. I didn't have to mess with the bus clock speed. Historically a lot of ISA bus issues were related to the bus being clocked to the CPU, obviously this would create a lot of issues. ISA bus normally runs between 4 and 8 Mhz. Modern boards should have a separate ISA bus clock or divider. It may be adjustable in the bios.

Looking through the manual the ISA clock is set for "PCI Clock/4". The PCI bus is at 33 MHz. So basically the ISA bus is 8Mhz by default. It is change able in the bios.

I was concerned the DMP Vortex86DX processor may have some issues but I haven't had any issues. The only issue ran into was the fact the LAN adapter required Plug-N-Play to be enabled which is odd for DOS.

[md63825]

Ordered the PCA-6743F-Q0A2E today from Advantech. And I'm gonna load DOS on my DiskOnModule along with the machine software. Should be able to stick it in the machine and go (fingers crossed). I like the idea of adding a USB port. Maybe later.

[md63825]

Received board today and installed. During software loading, computer requested Sys Parameter files, which I don't have. I used an older version of the software and machine will only run from disk. What's up with that?

[forhire]

Received board today and installed. During software loading, computer requested Sys Parameter files, which I don't have. I used an older version of the software and machine will only run from disk. What's up with that?

Did you copy cfgprms.sys and bmdcprms.sys off the old drive? Try placing them in the root (C:\) and then re-run the installer. Backup of those files are made when changes are made and the old copy is given a .bak extension.

On your older version that only runs from disk you may have to manually edit run.bat and fix the path.

Understand I've never installed clean from floppy... so I might be guessing.