Restoring a PC Server 500 P/390

Grant Taylor cctalk at
Sat May 12 18:58:31 CDT 2018

On 05/12/2018 05:07 PM, Dave Wade via cctalk wrote:
> I was so unsure of what I was doing that I haven't blogged, twittered, 
> or even Facebooked....

And here I went and asked you to air dirty laundry.  —  I'm sorry.

But I am grateful that you did so.  :-)  I did find it an interesting 
read, and I have a few comments that I'll share inline below.

> The server just about worked when I got it, but with six 20 year old 
> disks (I think they are twenty) in a flaky RAID array the thing spent 
> more time recovering dropped disks than it did working.  The spin up 
> time is critical, and like me I think these are showing their age and 
> the array controller gets tired of waiting for them to come ready and 
> then the array needs to be checked for consistency. Yuk.

Ya, I can see how that could be a problem.

What sort of RAID are they in?  One big six disk RAID 5?  Or is it 
something more exotic?  Striping across three sets of two disk mirrors? 
Is one of them a hot spare?

How big are each of the disks?

Are they true SCSI?  Or are they some variant of SCSI that IBM liked to 
mess with in the late '90s through the early '00s?  Serial Storage 
Architecture (SSA) comes to mind.

If they are standard SCSI, I'd be tempted to hook the drives up to 
another machine, image them, and likely run SpinRite on them.  (Order 
may depend on their current state.)

I might also be tempted to try to have the drives spin up and stay 
spinning, even if the machine is otherwise off.  An external enclosure 
with separate power would be really nice.  At least that would help the 
typical physical issues that drives tend to have.

Then, hopefully the drives would be stable and happy enough that you 
could focus on the RAID card.

> I was hoping to get the RAID working and copy the data to elsewhere, and 
> may still try and do that, but for now I have been implementing "Plan B":-


Is there still original data on the RAID?  Is it just intermittently 
accessible?  Just unstable enough that you can't rely on it for playing 
/ learning?

> 1. Cleaned the floppy drive. It’s a 2.88 and still a little flaky, but 
> it gets used a lot when messing with Microchannel and OS/2. The equivalent 
> of the BIOS config is run from floppy and it needs to be re-run every time 
> you move cards around.

Yep, I remember the System Reference Disks.  —  I've been messing with a 
Compaq ProLiant that has similar programs, but they reside on a 
partition on the drive.  Making it a little easier to run them.

> The CDs are not bootable and need at least two floppies to get them 
> loading so more reliance on the FDD.


My how things have changed.

> Its not simple to change the drive as IBM "re-purposed" some of the lines 
> on the cable that are "gnd" on most drives and used them to pass info 
> about drive. Plan is to try replacing it with a GoTek hack to provide 
> fake disk size info.  Some one has done this on a p70. Not sure if this 
> will work here.

Grr!  I think I'd heard that before, but did not realize the 
implications until now.



Well, at least it's information that might be a helpful start.

Do you need the 2.88 MB disk drive?  I thought that OS/2 and the System 
Reference (configuration) disks were 1.44 MB.  I'm wondering if you 
might be able to trade it out with a 1.44 MB drive that might be a 
little bit happier.

Also, I think that ThinkPad's used similar (decedent?) floppy 
technology.  There might be something you could take from ThinkPads and 
get it to work (with adapter) in the PC Server 500.

> 2. Messed with the RAID firmware, drive links and drives. Its still 
> Foo Bared. The system came with no CD Drive or 9mm DAT fitted. When I 
> popped that back I think it broke the RAID. For now I have un-plugged 
> the RAID card.


That means that the existing RAID array is inaccessible.

> 3. Installed a BT646 Microchannel SCSI card from E-Bay. Its SCSI/2 but not 
> as fast as the RAID card which is wide and of course can do multiple i/os.

I wonder if the RAID card has a RAM cache on it, and if the RAM might be 
failing.  Lord knows what it would take to replace the RAM.  Maybe the 
cache could be disabled?

> 4. Installed a SCSI2SD instead of hard drive. I have a 32Gb card in it 
> which works out a little less than what was in the server.  Getting the 
> config right for this proved fun. At present I have it set as 2 x 4gb 
> drives. The rest is un-allocated.

I've not yet had the pleasure of working with a SCSI to SD adapter.

I'm going to be messing with a Compaq Deskpro XL 560 which uses SCSI. 
I"m hoping to use a SCSI-to-SATA adapter and then use a small SATA SSD. 

> 5. There is a SCSI CD ROM on the interface as well. This seems to have 
> fits from time to time.

I thought the SCSI CD-ROM was fairly standard.  Meaning you can probably 
trade it out with a different SCSI CD-ROM or possibly even a DVD-ROM.

Sure it's not authentic, but it might be happier hardware.  Pick which 
problem you want to fight when.  ;-)

> 6. I had a couple of goes at installing OS/2 Warp Server 4 (This is Warp 
> 3 with server components). I couldn't get the server to boot from the 
> SCSI2SD but there is a setting hidden in the Server Config that must 
> have got lost.

If memory serves, you need to specify which card to boot from.  I don't 
recall if the system config specifies what drive on what card or just 
what card and subsequently relying on the card to know what drive (or 
fixed ID) to boot from.

I wouldn't be completely surprised to learn that there was a partition 
size / location / ID requirement to be able to boot.

I've long had problems getting OS/2 Warp 4 (CD from IBM) installed when 
booting from disks made from images on the CD.

I want to say that OS/2 and / or it's boot manager had to have the boot 
manager / partition be less than ~500 MB and within the first 2 GB of 
the drive.

I don't know that it was 500 MB exactly.  It's likely some multiple of 
or power of 2 or 10 and / or a binary counter width.

Remember the drives that would have been available for use when the 
machine came out.

Also, the RAID likely did some translation and might be able to take 
larger drives than the machine could handle directly.

> 7. At this point I had the SCSI2SD set as 2 x 1GB  drives but decided I 
> needed more space, so I re-set them as 2 x 4gb. The base OS/2 installed 
> OK but server portion barfed saying not enough free space. I guess a 
> pointer over flows. So spend an hour copying the CD onto the "C" drive 
> several times. It then installed OK.

I think I've heard tell of using a small partition for OS/2's boot 
manager and then maybe a 4 GB partition for the OS.

I believe that OS/2 will use drives / partitions larger than 4 GB, but 
they may be effectively limited to data drives.

All the reading that I've done on the P/390 installations have always 
had the P/390 stuff on separate drives, typically D:.

> So at this point I had an OS/2 system that booted. I couldn't get the 
> P390 software to install as it wanted Communications Manager and I 
> didn't have it.


> For those who don't know the base OS/2 has virtually no networking 
> included. IBM chose to separate networking as a separate product, 
> Communications Manager and charge a small fortune for it.

I don't know if that was specifically chosen on purpose or a side effect 
of how things were distributed at the time.

Remember that Most OSs didn't have native networking ability.  Windows 
3.x got it as somewhat of a back port very late.  Windows 95 had minimal 
networking when it first came out.  I think most of Windows networking 
was introduced in NT and shifted to 3.x / 95.

Also, I believe that Communications Manager was a product that could be 
added to an earlier version of OS/2 (same major version) that added 

Even when I install Warp 4 in VM, I see that the Base OS gets installed 
and then the Communications Manager (read: server) components get added 

I believe this also patterns after what mainframe OSs and other unixes 
did at the time too.

Ultimately I don't think this was malicious / extortionist behavior. 
Rather differences at the time.

> I think at this point I also installed service from a WarpUp! CD. I have 
> also installed Netscape 4.6 and InfoZip from this CD but not Java.


> However, I have since found that Personal Communications which includes 
> 3270 and 5250 terminal emulators also includes a "mini" version of 
> Communications manager and should be sufficient to run the P390 code.

Eh....  I don't think that /I/ would bet on that.  Maybe that is the case.

I've run into multiple different versions of / products from IBM that 
have communications in the name.  I think that Communications Manager 
was the networking add on for (and rolled into later versions of) OS/2. 
The Personal Communications that I've run into was more a client 
application including a terminal emulator.

> I have now installed that but at first I still couldn't get the P/390 
> support code to install. However, I found I wasn't installing the very 
> latest version of the P390 support code. That has now gone on, after 
> copying one disk in another PC as the drive in the server decided it 
> couldn't read it. I can now load the microcode into the card, but I 
> can't connect the 3270 emulator as a console.


See previous comment about 1.44 MB vs 2.88 MB disks and what you truly need.

> I have now re-read the documents and think I know what I need to do, I 
> don't have the IP port in the P390 config matching the port in PCOMMS.

Hum.  I wonder how networking on the P/390 and it's emulated 3174 (?) 
Establishment controller work.

If it's anything like Hercules, you'll need one IP for the P/390 and a 
different IP from OS/2.  —  I could easily be completely wrong.

> I also think I may need to tweak the OS/2 config.sys.

Quite likely.  I think the vast majority of OS/2's config lives in the 
config.sys file (or other similar files) and requires a reboot to apply 
the new settings.

> At some point I have also zipped up a mainframe OS from Hercules, copied 
> it to a CD and un-zipped it onto the server. Hopefully tomorrow I should 
> be able to load VM/CMS.

I'll be interested to see how that turns out.

> I also am still having issues with the Video Card. Its IBM SVGA Adaptor/1 
> which I believe should do 1024 x 768 but its stuck in 800 x 600.


I've found video drivers under OS/2 to be questionable.  I've been stuck 
in VM, which has it's own problems.

> I can't get PMVNC to run. It says its started but when I try the config 
> program it says it can't find the started program.


Thank you for sharing, it was a very interesting read.

Grant. . . .
unix || die

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