SpeedTronic MarkV <I> does not detect HDD of more than 4GBs?

We have Mark V system installed for our GE Gas Turbines.

However, upgradation of DOS-based Mark V <I> is in the pipeline but right now, we can't find HDDs in Market of more than 4 GB (as they have become obsolete) required for our HMI to run. The system does not read any HDD which is larger than 4 Gb.

I want to ask that if there is any other way other than Upgrading the Mark V Interface that we can run a HDD larger than 4GB to run in our system.

We have Pentium S installed with 133Mhz speed.

So, you want to install a HDD LARGER than 4GB in the Mark V <I>, because you can't find HDDs smaller than 4GB for purchase. Have you looked on ebay or a similar site? You may have to settle for a refurbished HDD (many are in fine condition; I use them regularly, though not usually for critical applications--but I have, and have not had any problems).

The ability of older CPUs and BIOS chipsets to recognize HDDs larger than 4GB is the problem. It's not that it's a PC configured to operate as an <I>, it's that back when those CPUs and BIOS chipsets were being built there weren't many HDDs anywhere near 4GB in size, and that was the arbitrary cut-off for recognizing HDDs. (I think SOME, but not ALL, BIOS chipsets had a manual method for recognizing HDDs of just about any size, but I don't think that would work with IDOS.)

Have you tried formatting the 4GB or larger HDD to something smaller and then seeing what happens? Yes, you would be not using the full capacity of the HDD, but if it works then the <I> would continue to work. (You may need to format it in another PC, and then swap the HDD to the <I> PC.)

I just looked at ebay for "250 MB IDE hard drive" and there were LOTS of them, some new, many were "previously owned" or "used." Try looking for different sizes (160 MB; 500 MB; etc.).

Hope this helps! Perhaps someone else here at control.com has another idea or suggestion and will write in to offer the benefit of their knowledge/experience.

Please write back to let us know how you fare!
Hi, did you tried to upgrade BIOS software, in general new upgrades bring new features, maybe new version recognize larger HDD.
I know its not so easy to find an absolut's upgrade!!! just try it who knows.

Good luck.

Thanks for your reply. Yes we have definitely tried formatting a larger HDD to less than 4 GB but still it does not recognize that larger HDD (the unused area remains unformatted).

Yes we have looked on eBay but there are other issues there as well such that our company does not have a policy on purchasing online and 2nd thing is that eBay does not deliver directly in Pakistan. So its kind of a roadblock here.

I kind of am looking for a solution in which the CPU/Bios might be able to detect larger HDDs, preferably SSDs these days.

Thanks in advance.

I was pretty certain this was the case....

If I recall correctly some HDDs had a jumper which could be used to enable or disable the automatic detection. It sounds as if the BIOS on the <I> you have is able to automatically detect the HDD and its size and so even if you format the drive so that C: is smaller than 4GB it still recognizes the total size. Can you find any jumpers on the HDD and reference them in the instructions?

Have you tried contacting the HDD manufacturer to see if they can offer any help?

Have you tried any local PC shops to see if they have any HDDs which would work? Maybe even purchase an older PC with a suitable HDD and reformat it to erase it before installing it in the <I>?

This is where you have to get creative.

I don't believe you could create a virtual machine of an <I> and then run it to communicate with the Mark V--because I don't think there are any drivers for ARCnet cards for VMs.... And, probably not any for the implementation of ARCnet GE used for the Mark V StageLink.

I wish you luck in your endeavour--please write back to let us know how you fare!

I found this:


It's pretty old, but it might be helpful....

Another thought I had would be to look in the BIOS settings and see if there's a way to disable the auto HDD detection. If you can do that (if there are no jumpers on the HDD to disable that) I think you would still need to partition the HDD with another PC, using FAT16 first, then maybe FAT32 if that didn't work, into smaller partitions. I would partition the entire HDD into smaller partitions, making one partition (C:), say, 500 MB or so, and then use that one for the <I> stuff.

Again, let us know how you fare. I would be surprised if you could find any third-party software to recognize larger HDDs because during boot-up, IDOS takes over the CPU and I/O and schedules MS-DOS 6.22 as one of its 32 possible tasks, so IDOS would have to work with the software and it doesn't like working with software other than what was shipped on the <I>.... And, one has to understand why: We're talking about controlling a multi-million USD piece of equipment which burns combustible fuels and may have a hydrogen-cooled generator on the end of it (which can also explode!). IDOS remaps some interrupts, and takes over from MS-DOS, also, and it's because GE didn't want just anyone or any software to be able to control the turbine--because it would be TOO DIFFICULT and EXPENSIVE to qualify every piece of software, and hardware, for use with the Mark V.

Does your PC have an IDE hard drive interface?

If it does then you can buy an IDE to compactflash adapter and use it with a 4GB or smaller compactflash card. Check your local computer stores or eBay.

StarTech.com 40/44 Pin IDE to Compact Flash SSD Adapter - IDE to CF Card reader



Use a PCI SCSI controller with a 4.3GB or smaller SCSI hard drive.
SCSI is still out there and available.

good luck