Great machine! 😁
I wish you the very best for the restoration!

Brostenen,

Do you happen to have the original software for your PW2-300/10, and might I be able to persuade you to create disk images of them? pretty please?

Since I believe, my motherboard is a different revision than yours, I'm also curious what version of ROM BIOS yours has (and if they're cross compatible).

QBiN wrote:

Brostenen,

Do you happen to have the original software for your PW2-300/10, and might I be able to persuade you to create disk images of them? pretty please?

Since I believe, my motherboard is a different revision than yours, I'm also curious what version of ROM BIOS yours has (and if they're cross compatible).

I have no clue on to what revision my board has, and what BIOS it is running.
For the sys disk, I have attached a ZIP file.
It is created with Win-Image and is in IMA extension. 1.44mb Floppy.
I have the 5.25 inch install disk, yet I have no drive nor means to create a 1.2mb
image file out of that disk. Sorry...

If you wish more informartion, I might scan the entire system manual, or at least
take pictures of it. It is a big one, so I need the time to do it.
PM me for the manual, and I will remember to do it in the next week or two. 😀

The harddrive number should be number 9. It is written on the harddrive it self.
On the image file I posted, there is a "park" utillity, that you need to use when transporting or moving the machine.
It is used to park the heads. This is important to know. Park before powering off every time.

The spec's of you'r Unisys is 99% identical, to that of my Unisys. Paradise EGA, 640kb, 20mb. (Mine came with 1.44mb)
I have upgraded my machine a bit: CL-5424, 40mb-SCSI, Adaptech SCSI Controller and YMF-719 (YMF-718?)
It is running Dynablaster, Monkey1 and others alike, without problem. Lotus Ultimate Challenge are too much tough.

It can run with SCSI as I mentioned, and it can run with IDE as well. Just need the right controller.
When I had it set up with IDE, I installed a standard non-enhanced 16-Bit Controller.
Then I installed a 640mb drive, set it up as 47 in the BIOS, and ran a Dynamic Drive Overlay (EZ-Overlay).
After that, I just installed Dos the usual way. Though edit can not copy and paste, and I suspect it is because
it has no more than 640kb memory at hand. The same issue with SCSI as well.
I have not tried running MS-Dos 5 on this machine yet. Only 3.3 and 6.22.

Hope all this can be at any help for you.

Some 5 to 6 hours later....

I have scanned all 270 pages of the manual, and it is one big chunk of data.
The complete size is 6.74 gigabyte uncompressed, so I actually need to know
were I can dump all the data.

The manual holds information about the EGC2 gfx adaptor (Paradise card)
and stuff like a complete chapter for 1.44mb floppy and so on.
Really extensive and in dept knowledge. It is after all the original 1988
service/system-manual, and they did a great job back then.

EDIT: (The original bad-boy)

EDIT 2:
Finished compressing the files. 3.46 Gigabyte in size.
Now... Were to dump it?

Wow, Brostenen. Thank you for going the extra mile.

I need to think of a way to be able to receive the scans. My dropbox doesn't have that much space. I'm open to ideas.

I was able to get the STARTUP disk booted and set the BIOS, but unfortunately it appears the 20MB MFM drive is dead. The HDD LED lights up a few times, but it never spins up. Eventually the BIOS POST reports an HDD failure, but I can continue to boot to floppy. I'd like to find a working MFM drive for it. My original PW2-300/10, I believe, came with a Seagate instead of the Miniscribe HDD this one came with.

Here in a day or two, I'll remove the BIOS chips and take an image of them in a ROM reader/burner. I'm intrigued by the extra DIP sockets next to the ROM. It makes me wonder if the motherboard will accept an arbitrary boot ROM.

Yeah....
I have seen them empty sockets as well, one of them is were you plug in a 287 co-processor.
Even think it is labeled on the PCB.

A shame that the HDD is dead. It really sounds special, when it is running.
The downside of that miniscribe is that it is really loud.
If you are having trouble with the BIOS battery, it is not that expensive to replace.
I bought a battery from china, and soldered the wire from the original to it.
I just made shure it was a lithium and was rated at 3.6v

Regarding the manual. Does someone here know if Vogons drivers will accept such a large file?

Did a convertion of the scan's. Now they are JPG and a lot smaller in size.
I have uploaded it to Vogons Drivers as well as the system installation disk.
Hope you can use it. 😀

Any progress on you'r Unisys restauration?

brostenen wrote:

Any progress on you'r Unisys restauration?

Yes, in fact. I've been working on it quite a bit today. I'm currently trying to figure out the memory expansion... more on that later.

Earlier, I acquired a Seagate ST-125 20MB MFM drive via eBay recently. I swapped it into the 286 since the Miniscribe was dead and not spinning up. Thanks to the STARTUP disk image you provided, I was able to add it to the BIOS, low-level format, fdisk+format, and install MS-DOS 6.22. That all went really well. I also added a Western Digital Paradise 90C30 VGA card in place of the EGA card. That was a huge plus, because now I don't have to borrow the EGA monitor from my IBM XT just to boot the 286.

I also swapped out the 5.25" floppy drive with a dual 1.44/1.2MB floppy drive. Here's a picture from the front while the 286 was running scandisk against the MFM drive.

I took stock of the on-board DRAM chips and counted them up:

I'm trying to discern, based on the current chips, what chips I need to plug into the open DRAM sockets to get to 1024KB. So far, I can't get the math to add up to exactly 1024. I believe the machine can accommodate 640K Base + 1024K Extended max. I'm a bit confused that the onboard ram adds up to 720K. I'm also stumped at the moment with what to put in the open 8x DIP-20 and 4x DIP-16 sockets. Eight 256x4bit DIP-20's will instantly get me to 1024KB, but then what about the remaining 4x DIP-16 sockets? I need to think about it some more. I don't want to have to start tracing the traces to figure it out.

My To-Do list still has the following:

• Obtain a replacement CMOS battery pack
• Test a spare IDE drive with a Promise EIDE controller (w/BIOS) that I have
• Build a shorter 34pin floppy cable
• Test an 8bit NIC with MS DOS Client (for windows SMB share access)
• Practice and get ready to retrobrite the front case bezel

That's it for now. Some progress... little by little. I have a feeling this thing will cost me a few hundred dollars to restore completely. But this is turning into a labor of love for a machine that's the same as my very first PC. I suppose some things you can't put a price on.

Cool. Nice to see that you have come this far. The memory question is a bit tricky I know, and the manual have no real clue on to what exact modules you need to use. I did check it some time ago, when I investigated it. As for the battery.... Well..

I have used a battery like this one, and soldered on the original wire (cut it off the original battery and soldered to the new)
http://www.ebay.com/itm/Tekcell-3-6V-1-2AA-SB … DIAAOSw-vlVnj5C

And ended with this result:

As for the replacement harddrive, I have a feeling that you need to use the "PARK" utility that are on the installation disk.
These old MFM drives have no autopark function, and crashing heads are a disaster on drives this old.
I think this is why my miniscribe is still working without any bad sectors. The util was used before 20 years of storage
in my parents basement. Or it was because they have a warm and dry basement. (or both perhaps)
Yeah... It was sitting all these years without any powering on at all.

EDIT:
I allmost forgot to ask you what you'r take, is on this machine?
I don't know if it's because of nostalgic reasons, but my take on the Pw/2-300 is as follows.

This is an amazing machine, in superior build quality. You can throw games at it, up to around games as Lotus Ultimate Challenge.
Lotus is the limit. It runs horrible on this machine. So games up to, not uncluding this.
Games such as Monkey1, Lemmings, Stuntcar Racer, Street Rod 1 and 2, Civilization and such.
Runs without any trouble. Actually pretty well. Not too fast nor too slow, and there is a giant catalogue of games before that.
Wich this machine will run all of, without issues. Plus this machine is a pure workhorse. Super, super stable.

QBiN wrote:

I almost forgot to ask you what you'r take, is on this machine?

Well, like you, this is the first home computer my family ever owned. So my opinions are heavily subjective. I haven't had time to enjoy it yet, because it's not restored to the point that I can do that. However, I agree with you. I remember it being extremely stable and physically built like a tank.

While the first computers I ever used were the IBM PCjr's in my elementary school's computer lab, all my first games and attempts at programming were on this 286. I first got online with the Prodigy service on this machine, and later, found a whole new online world in BBS's on this 286. It never let me down. Some of my favorite games on it were Wing Commander, 688 Attack Sub, Monkey Island, and Lemmings.

My only complaint is/was the lack of expansion slots. I only ever had a single spare ISA slot to play with. Depending on what I was doing, I had to choose whether a serial port card (for modem/Prodigy/BBS use), sound blaster, or Quantum Hard Card (because 20MB was tiny) would occupy the third slot depending on what I wanted to do. That meant I pulled the case cover off A LOT -- which was a pain. If I needed space AND sound blaster, I was out of luck.

I'm already trying to plan my "upgrades" to it, and I'm having to think creatively around the lack of slots. I'd like to have a NIC in it as well as a MPU-401, but I'm not sure how I can accomplish that yet. We'll see. I'd LOVE to find one of those ATI VGA Stereo F/X or MediaVision Thunder & Lightning cards for this thing.

A quick update... I got a hold of a 3Com 3c503-TP "Etherlink II/TP" NIC and installed it in the Unisys 286 in the lowest slot on the riser.

What's interesting is that slot is an 8bit only slot, but the 3c503 is one of those handful of cards that, even though it's a 16bit card, will also operate in an 8bit ISA slot.

I then installed Microsoft Client for DOS (which includes drivers for the 3c503) so I could start transferring files over my network instead of dealing with floppies or even a Gotek. Transferring files straight from a network share is always preferable if I can make it happen. I also replaced the backup battery.

I'm still stuck on figuring out the memory expansion, but I haven't given it much thought lately.

Hello, I'm sorry to resurrect this thread, but it's for a good cause! 😀 A friend and I figured out a compatible memory chip selection to expand the memory with an extra 1MB, emulating the "mythical" memory expansion kit as stated in the manual.

My board seems to use mostly HY53C256LS-80 for the conventional memory (I didn't disassemble everything, so I'm not sure on all chips). So that was the starting point: there's 4 free DIP-16 sockets, which would mean, if using the existing chips, 4*32KB = 128KB. Makes sense for the parity bits of the promised 1MB (1024/8=128). The other 8 sockets are DIP-20, and must total 1MB, so each chip should have 128KB, and probably 80ns to match the rest of the memory. Our guess was the M5M44256BP-8. And it turned out to work perfectly!

So to recap, my suggested unofficial memory expansion kit:
- 8x M5M44256BP-8
- 4x HY53C256LS-80

Don't forget to set the jumper next to the DIP-16s. On first boot the BIOS already sees 1024KB of extended memory but complains the configuration has changed. Simply set 1024 in the startup utility. I tested it with CheckIt, and running Windows 3.0 in standard mode with multiple applications, and even SCO Xenix. Everything seems to work just fine. Please note I don't have experience with machines this old and I may be doing something completely wrong. Nonetheless, I hope it helps someone. Finally, enjoy some photos (please excuse the dirt).

I'm very grateful to Brostenen, who in this thread scanned and uploaded the full manual. I couldn't have reconfigured the Paradise video card without it, nor figure out the RAM expansion.

Trivia: I'm using an IBM 5151 that was recently rescued from a literal pile of trash, and my Unisys PW2 was the only machine I had with TTL video, after reconfiguring the Paradise for Hercules compatibility. But this machine had been in storage for decades in rough condition. Thus began a trip down memory lane, since this was my first PC, albeit with EGA monitor that unfortunately is long lost, and that drove me to repair this machine to working condition... and beyond.

Welcome to VOGONS mirag. You obviously did something right 😉. Well done.