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Hard disc recommendations

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bettablue

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OK, so I'm having trouble with a couple of hard disc drives. One of my MFM drives is an 11 MB MiniScribe full height unit and the other is a 10 MB Xebec full height MFM drive. One is installed in my IBM 5161 expansion unit, and the other in my XT machine.

I've been doing a lot of reading and have learned that the MFM drives in general are quite troublesome, so I was considering the purchase of a pair of SCSI drives and controllers. The only bad thing about this is that in order to completely replace all of my MFM drives, I will need 2 SCSI controllers, and three hard disc drives. I also understand that the size limitations are pretty much non existent in regards to the original IBM systems.

So, right now, I'm curious if replacing the MFM drives with SCSI drives would be worth the money. I know as an investment, SCSI drives will be much more stable. But I have already made a deal to buy 2 Control Data MFM hard discs.

What are your thoughts on replacing the MFM drives with SCSI in the next year or so? Should I, or not?

Thanks much.
 
Get something Solid State. Then you won't have any problems and since they're IDE interface devices they're even much simpler to install than any of the other varieties or types. :)
 
MFM refers to the technology used in the drive. You are mistaking the interface with the technology.

A 25 year old MFM drive with a SCSI interface will have the same problems as your 25 year old drives with the ST506 interface that you are using now. You will need a mid 90s or later drive, and those are still pushing 20 years old.

Go with XT IDE with FLASH like people are already recommending you to in other threads.
 
A blatant plug for my site... but I'm expecting more PCB stock in the next couple of weeks - Lo-tech.co.uk Shop

I'm also intending to offer a small number of boards assembled and tested. And maybe even a couple of 500KB/s XT-CFv3 boards... I found two CPLDs. Those will be the last of them though, since the 5V CPLDs are all long gone now.
 
I can understand you wanting to keep the machines as original as possible but like others have said XT-IDE is a good way to go and will likely save you money in the long run, Those old hard drives are really pushing past their life span, I have XT-IDE rev 1 cards in a couple of my machines and they work very well.


bettablue said:
OK, so I'm having trouble with a couple of hard disc drives....
Click to expand...
 
I have been using an 8 bit scsi card (Seagate ST01) with external hard drives from the beginning of my vintage hobby. I was in love with the big old IBM WD25 drive in my XT, but I didn't trust it, so I was wanted the scsi drives to keep things backed up. I started buying old external units originally for the Mac, and my experience has been that the oldest ones have all the same issues as the ST506 drives do. I ended up buying a couple of 3.5" Quantum Pro drives (both 250 meg) 50 pin scsi from ebay. They have been rock solid, but they lack the character of older drives. The issues I've had with scsi are as follows.

Had to upgrade the bios on the Seagate controller to recognize the Quantum drives.

Had power supply failures in the external enclosures (bad capacitors). One of them damaged two of my hard drives before I figured it out!

Scsi is rather mysterious. I have never successfully connected more than one drive. You are supposed to be able to have up to seven devices on this card, but I can't get it to work.

I had one full size CDC 150 meg scsi drive installed in the XT for a while, but it started to fade on me.

Conclusion. Old hard drives are old hard drives, regardless of interface. A scsi controller might well let you use newer drives as it has me.

I do feel I have to draw a line somewhere on how much modern equipment I use on a vintage machine. It's all about how you use the computer, of course, but what about 4164 memory chips that like to pop off, or capacitors that like to fail? If you want a fast, quiet, reliable computer, just buy a new one, and that's no fun at all.

P.S. The old IBM WD25 drive in the XT has sailed right on without issue thru all my scsi playing around.
 
Again, thanks Mike. The reason for this thread is fairly simple. I was hoping to get information regarding the MFM drives vs. SCSI in terms of performance, and the fact that SCSI drives are not only cheaper, but more reliable, faster, etc. I got the answers I was looking for. However, as I had stated, I'll be buying 2 XT-IDE boards for my IBM machines. I have a lot of questions regarding the XT-IDE, but those I'll get answered as I do more research in VCF, and the XT-IDE web site. True, vintage hard drives are getting long in the tooth, regardless of the technology, but they are more reliable. MFM drives have a reputation of not being that stable, so, in that regard, SCSI is the way to go.

I have made the decision to go with the XT-IDE board for both of my IBM computers, as well as my Compaq Portables, and other systems compatible with the PC as their drives begin to fail. However, I'll probably buy the 1st revision boards which have already been assembled and tested. I've watched some videos on YouTube and other sites covering the XT-IDE installation, and set up. And from what I can tell, it's really pretty simple. I agree that using drives of the ages you specify is pushing their longevity to lengths that they were never meant to surpass, but still; if I can keep them working for just a little while longer, then I'll try to stay with the technology I'm somewhat familiar with.

The only thing I would want to do in addition to swapping out the hard disc drives is to see about finding a rear expansion plate that has either the CF, or USB adapter, or possibly even one adapter for both which would take up only one expansion bay on the rear of my expansion unit, and the XT machine. Can someone point me to a couple of adapters that would do the job?

Again Mike, and everyone who replied... Have a Very Merry Christmas and Happy new Year..

Thanks again...

~BB~

mbbrutman said:
MFM refers to the technology used in the drive. You are mistaking the interface with the technology.

A 25 year old MFM drive with a SCSI interface will have the same problems as your 25 year old drives with the ST506 interface that you are using now. You will need a mid 90s or later drive, and those are still pushing 20 years old.

Go with XT IDE with FLASH like people are already recommending you to in other threads.
Click to expand...
 
"MFM drives have a reputation of not being that stable, so, in that regard, SCSI is the way to go."​

Once again, you are confusing MFM and SCSI. When you say MFM you probably mean ST506 interface which is what the old Xebec controllers used in the XT class machines use. SCSI is an alternative controller. Drives using both ST506 and SCSI can be built on "MFM" techology, which refers to the electronics and mechanisms within the drive.

Use the Seagate ST-225 as an example. The common version of this drive is the ST506 interface. The SCSI version is the ST-225N. Both are MFM drives - the only difference is the controller they use. And both are going to be equally unreliable at this point.

Your only benefit to going with SCSI is that newer SCSI drives will generally work on older controllers. So you can cheat death a few years by running a 1GB drive on an old 8 bit controller. That is a good reason to use SCSI, at least for a few more years. But 8 bit SCSI controllers don't grow on trees ...
 
You are exactly correct. I was, and probably will still be confusing the technologies. Hopefully, after doing some additional reading, I'll get it straightened out, but in all actuality Mike, you have already done most of that for me already.

As always... Thanks again. This little bit of education will go a long way.


mbbrutman said:
"MFM drives have a reputation of not being that stable, so, in that regard, SCSI is the way to go."​

Once again, you are confusing MFM and SCSI. When you say MFM you probably mean ST506 interface which is what the old Xebec controllers used in the XT class machines use. SCSI is an alternative controller. Drives using both ST506 and SCSI can be built on "MFM" techology, which refers to the electronics and mechanisms within the drive.

Use the Seagate ST-225 as an example. The common version of this drive is the ST506 interface. The SCSI version is the ST-225N. Both are MFM drives - the only difference is the controller they use. And both are going to be equally unreliable at this point.

Your only benefit to going with SCSI is that newer SCSI drives will generally work on older controllers. So you can cheat death a few years by running a 1GB drive on an old 8 bit controller. That is a good reason to use SCSI, at least for a few more years. But 8 bit SCSI controllers don't grow on trees ...
Click to expand...
 
bettablue said:
The only thing I would want to do in addition to swapping out the hard disc drives is to see about finding a rear expansion plate that has either the CF, or USB adapter... Can someone point me to a couple of adapters that would do the job?
Click to expand...

Surely, this?
 
I really like the XT-CFv2 board that I have--nice slot for a CF card in the bracket. The only fly in the ointment is that it does require SMT assembly skills, but I didn't find that daunting--just a good iron and some soldering braid--and a good magnifier. Performance is excellent.
 
Excellent Chuck! Unfortunately, my soldering skills are up to the task, but my vision isn't due to complications of diabetes. (Yeah, just one more nail) Still, I think getting one already assembled isn't unheard of, and they are much less expensive than the CFFA3000 board made for the Apple II line. For now though, I'll go with the option that will cost me the least, and that means, buying 2 Control Data full height drives and configure my MFM controller for those in both my 5150, and 5160. Then I can begin saving for 2 XT-IDE boards. At least my computers will be functional until I get the XT-IDE upgrades.



Chuck(G) said:
No connection to the XTIDE--this is a complete controller using a CF card instead of an IDE drive.
Click to expand...
 
I'm a big fan of James' XT-IDE CF Lite cards...though so far I've only managed to get one of the two cards I have assembled. An easy build, small form factor, and it just worked! If you want the external option for the CF cards, you can run a cable to a IDE to CF slot adapter...search ebay for item # 221250436153 as an example. I've got an original XT-IDE card in my old Tandy with two of those adapters in it. Works great...I'm hoping to get a few more of James' cards when he gets more to sell...then I can have them all the old machines I want to tinker with.

I'm assuming the answer is no, but does anyone know if the original XT-IDE and XT-IDE rev2 boards still available for purchase anywhere?

Wesley
 
That sounds great! Now you've brought up another question though. You mention using two of the adapters in your Tandy computer. Could you clarify that for me please?

Do you mean you have two XT-IDE boards installed, or are you talking about running just one XT-IDE with two CF/USB adapters with external elots on the rear of the PC, allowing the insertion of separate CF/USB slots?



wesleyfurr said:
I'm a big fan of James' XT-IDE CF Lite cards...though so far I've only managed to get one of the two cards I have assembled. An easy build, small form factor, and it just worked! If you want the external option for the CF cards, you can run a cable to a IDE to CF slot adapter...search ebay for item # 221250436153 as an example. I've got an original XT-IDE card in my old Tandy with two of those adapters in it. Works great...I'm hoping to get a few more of James' cards when he gets more to sell...then I can have them all the old machines I want to tinker with.

I'm assuming the answer is no, but does anyone know if the original XT-IDE and XT-IDE rev2 boards still available for purchase anywhere?

Wesley
Click to expand...
 
bettablue said:
That sounds great! Now you've brought up another question though. You mention using two of the adapters in your Tandy computer. Could you clarify that for me please?

Do you mean you have two XT-IDE boards installed, or are you talking about running just one XT-IDE with two CF/USB adapters with external elots on the rear of the PC, allowing the insertion of separate CF/USB slots?
Click to expand...

Sorry for the late response...I can't seem to keep up with posts here.

One XT-IDE board, two IDE to Compactflash slot adapters connected to it.

Wesley
 
I've made a deal to buy the two Control Data Systems hard discs. :p They are a matching set of full height 30 MB each, using an MFM controller by Western Digital. Since the drives are basically twins, I plan to install both into my 5161 expansion unit for a more "finished" look when the cover is removed. I've found that little things like that not only look tidy, but since they're both the exact same drives, it will be much easier to setup the drives when I install them and configure the controller.

Then too, the price is right. The seller is giving me both drives for only $50.00 total! That's $25.00 each. :p I can't buy an XTIDE for that. Eventually (meaning later this year) I plan to buy at least one XTIDE and install it in my XT machine to see how it works. If it does what I want, then I'll consider putting the XTIDE into my expansion unit. But that brings up a couple of other questions. :dunce:

1. Since the XTIDE has the capability to use both a USB thumb drive, and a CF card, can I have each one assigned it's own drive letter?

2. Can I have a USB adapter, and a CF card adapter installed to the rear of the computer for easy access? I know of a couple of adapters I've seen on E-Bay, but I'm not sure if I can get one rear expansion bay adapter that has both a USB and CF card adapters. Am I barking up the wrong tree with that kind of adapter?

Finally, I may even just wait till the hard disc eventually fails all together, then replace the hard discs with an XTIDE board. Who knows, there may be another revision by then. :frankenstein:

As always, I would sincerely appreciate your opinions and responses.

Thanks in advance.
 
An XTIDE with CF is a brilliant device to have.
But I would never remove perfectly working vintage hard drives. Just my opinion, I just think they're part of the whole IBM 516x experience.
 
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