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Just a quick note for all those who have gotten to know Tom. He is in the hospital again more throwing up blood. I’ll update the post when we know more.
Ed has been working on my IBM and expansion unit for the last three to four weeks now. It’s not because Ed is just taking his time, but because there are so many other things going on in his life. I am actually surprised that he’s gotten as much done as he has.
Now that the final stage of assembly is done, Ed has been trying to get the boot drive configured, so he can run a low level format. For those of you who have never had the pleasure, in order to use a drive for the first time, or in many cases, the first time with a new controller, the drive had to be low level formatted, then Fdisk had to be run followed by a standard Format. All that had to be done before the operating system could be installed. Luckily the installation of the operating system, or OS only took a few minutes.
Well that’s how it is supposed to work. However there are some combinations of drives and controllers that just don’t like to play well together. So other programs are there to help. In this case, a nifty little bit of code called Spinrite. Spinrite is a great utility to completely wipe a drive, and allow the low level format of older drives. The program is pretty system dependant though. You don’t want to run Spinrite for Windows on one of the first hard disks because the low level format is missing. Low Level Formatting was made obsolete with the advent of newer smarter hard drives.
So that’s where we are right now, or to be more specific, that’s where Ed is right now. I know there were two versions of Spinrite in the software collection I gave Ed when he took the computer, but neither of us know just yet if either version will get him through that final stage.
Ed is and always has been my best friend. So I will give him all the time he needs, and hope that it won’t be much longer. After all, you can’t just take a vintage IBM to a computer repair store in Las Vegas. The very first thing they will tell you is to buy a new computer.
So I will say to Ed: Thank you very, very much. I hope you’re feeling better, and above all, I hope Alice goes smoothly from this point forward just so you won’t have to work on her, and that will be one less thing you have to worry about.
I can’t wait to see all the pictures and the documentation. We’ll be posting Alice’s final rebuild as soon as Ed has her up and running. We’ll be including data sheets for each and every piece of hardware installed. We’ll also include a pic of each part on each data sheet too. Once we have all of the data sheets assembled, we’ll create a binder which you can purchase here through our page. The binder will include instructions for installing each piece of hardware, how to set the IRQ, if one is required, and programming considerations.
As always, please feel free to contact use here by clicking on the Contact link. Leave your comments, questions and suggestions. We would love to hear from you.
Those of us born in the late 1950’s to early 1960’s have a unique perspective on life and technology. We grew up and watched the world change around us. We watched as video games came from the arcade and into our homes. We watched as early gaming systems became more and more powerful, and we watched as the personal computer made it’s way into our living rooms. Names like Commodore, Apple, Radio Shack and finally IBM were commanding and demanding more and more attention.
By the time children of that time frame made it their teens, they saw a completely different world than the one left behind. Transistors were making way for new IC chip technology, which meant that some of the items on our homes could be made with far fewer parts, and far smaller than the same thing manufactured only 10 years previously. At the same time though, IC chips were themselves a new growing industry. There were only a handful of locations on the planet where these new chips could be manufactured. Circuits were tiny, yet chips manufactured back then don’t come close to the complexity of new chip designs.
It was the advent of the home computer that drove IC chip production and eventually made the transistor obsolete. Think about it. When was the last time you saw a ‘New” transistor radio being sold at the local drug store, electronics store or even big chain locations? The same thing happened with fuses.
Edison and Marconi were both experimenting with radio waves and equipment during the late 1800’s using equipment that would be considered crude by today’s standards. So while the first radio receivers relied on crystals; there was no effective way to amplify their volume. And while Marconi was explaining to the world how on Dec 12, at 12:00 PM, he received the first ever Trans-Atlantic radio broadcast.
It wasn’t until 1905 to 1907 that the very first fuse radio receivers were being developed. An American named Lee de Forest, a competitor to Marconi, set about to develop receiver technology that did not infringe any patents to which Marconi had access. He took out a number of patents during the two years between 1905 and 1907 covering a variety of developments that culminated in the form of the triode valve in which there was a third electrode called a grid. He called this an audion tube; the very first tube amplified tube radio. From there it took only
Transistors were developed beginning in 1947, and within only a couple of years, the size of radios went from large cabinet sized furniture pieces that sat next to a wall, or in a corner to something that could be carried in a coat pocket. Components also shrank in size and number as transistors made their way into every aspect of our lives. And while the transistor made things simpler and more reliable, the next phase in electronics development, the IC was just around the corner.
IC chips replaced not only the transistor, but diodes, capacitors, and other electronic components. That made it possible to create entire circuits on a single layer of silicon. That small piece of silicon would then become the new backbone of the electronics frontier, and again, the children of the ’60’s were there to watch it all happen.
The first IC chips in computers were very simple in comparison to today’s’ massively compressed circuitry designs. Yet their use effectively made the home computer a reality. If not for the creation of the IC chip, computers would still be quite rare, and only a handful would probably be in use, simply because of the size requirements to duplicate the circuitry of the IC chip using standardized components. Those components were not nearly as reliable either.
Think of it this way. Your home computer has enough transistors; over 3 million in fact, that in order to create a circuit board to contain just them, not including diodes, capacitors, etc. the circuit board would be well on the way to becoming the size of the wall on the side of your home. And that is just one chip.
So yes, we children of the 60’s have seen a lot of changes. In fact there were more changes in the 1960’s alone than in the previous hundreds of years. It’s a wonder we were all able to keep up.
Well, well, well… Here we are again.
The final pieces of the puzzle have arrived and are ready to be installed. Unfortunately, I was hospitalized over this last weekend due to some unfortunate health issues, so nothing was done on the computer.
As everyone who has been reading my posts knows, my IBM 5150 Personal Computer is completely restored to it’s full capacity. No, I’m not going to repeat the specs; sorry. You can see my IBM 5150’s specs in previous posts. What I will fill you in on though is the IBM 5161 Expansion Unit for the IBM 5150 Personal Computer.
Calling the expansion unit rare is really an understatement. These expansion units weren’t all that popular at their initial release mainly due to cost. And when users found out that they could retrofit an IBM 5160 mother board, and other components into the 5161’s case to effectively make an IBM 5160 XT, many of the internals for the expansion unit were put aside, and eventually lost, or recycled, never to be seen again. Which brings me to the current state of my own expansion unit.
I had planned on building my own expansion unit by using an IBM 5160 XT case as a starting point, and a few “off the shelf” parts. Previously, a friend in the Vintage Computer Forums had given me a complete set of cards for an IBM 5161 expansion unit. These included both the extender and receiver cards required to connect the expansion unit to the host PC. For privacy concerns, I won’t give any names unless I have their complete approval. The point here is that the extender and receiver cards are so rare, they have become virtually priceless;especially the extender card.
By using these cards as a starting point, my plan was to install an XT power supply, a standard 8 slot 8 bit ISA passive backplane and the other components as needed. The backplane would be the starting point for the rest of the expansion unit’s build. However, things didn’t quite work out that way, as I had mentioned in another post. Another expansion unit became available for only $40.00 plus $22.50 in shipping! Let’s just say, it was a deal I couldn’t refuse. That price did not however include any hard disc drives, but it did come with the original MFM hard disc controller. Replacing the missing drives and upgrading the controller to a Winchester model cost an additional $65.00. So for less than $130.00 I had a complete working, and most importantly, an authentic IBM 5161 expansion unit. The drives I purchased were an original 10 MB full height MiniScribe, and a 30 MB Control Data drive which was removed from a Compaq computer of about the same time. The MiniScribe drive eventually decided that it didn’t like it’s friction bearing any longer and decided to quit, so I purchased another 30 MB full height Control Data hard disc, along with a 40 MB drive which I used in refurbishing an IBM 5160 XT. But that is another story for another time.
The expansion unit, using the extender and receiver cards, works great. The IBM PC is now completely dependant upon having the expansion unit available and booted prior to powering on the main PC. The expansion currently has twin 30 Meg Full Height MFM Control Data hard disk drives, coupled with a dual 9 pin serial port, an Intel 8/16 LAN adapter, and a 3Comm 9600 baud modem. Finally the receiver card is installed in the very last available slot in the expansion unit. This is as the installation was intended. Today, I opened the last box of parts needed to round out the compete setup: a brand new, still shrink wrapped Western Digital 8 bit MFM controller. The hard disk controller came pre-configured for the Miniscribe disk drive as drive “C”, and the Control Data as Drive “D”, so the installation was pretty straight forward. There is one area that needed special attention. Standard MFM cables are too short to install 2 hard disk drives in this configuration, so another friend in the Vintage Computer Forums assembled a completely new custom set of cables to accommodate the added length required for connecting both drives to the controller.
I worked with Ed Hall; our site admin, and computer expert, to finalize the completion of my system over a few days. Of course, a complete set of photos of the system build was posted to All Things DOS, and on our sister site on Facebook under allthingsdos. (That is correct, no spaces)
The last thing I wanted to mention here today is the cost. I got lucky, extremely lucky! The entire cost of my IBM system, including the IBM 5161 expansion unit, printer monitor, and all of the peripherals and upgrades came to only about $475.00. A lot of that was to cover the cost of shipping the various parts, and components.
One thing to remember: Don’t think you can just go to Google and get a vintage computer locally, (although you might get lucky), however, keep your eyes open. The very same system as mine recently sold for over 10,000 to a collector. Yes, that is correct; Ten Thousand Dollars. My system is not for sale though. However, if you have any questions regarding your own 5150 project, or if you happen to have or find a genuine IBM 5161 expansion unit, you can make some money.
Please contact me if you have any questions about what you read here. I’ll be more than happy to help you. If I can’t, I’ll forward your request to our computer expert for a resolution.
Thanks for reading everyone. Have a great day.
The numbers are growing. Vintage computer users are beginning to pop up everywhere; some in organized groups, but mostly just individuals on their own. Most people who go into vintage computing do so with a particular reason on their minds. I have already discussed some of those, but today I will be focusing on an ever increasing number of vintage computer users whose main reason for going back, is simply because they’re tired of keeping up with the rat race.
Ever since Windows 3.1 was released, computer manufacturers were in a race. Software vendors were writing new programs that would constantly push the boundaries of what current computer system and their software could accomplish, and nowhere was this more true than in the area of games. Games became more and more resource hungry, needing more memory, and more storage space and even more processing and video power than ever before. This has continued to this day. And Windows itself is also to blame for sluggish response.
Back in 1995, a “decent” home computer was still an expensive proposition. Windows 95 was being installed on more computers, but in the manufacturers didn’t always install enough memory or include processors that were truly fast enough to run the applications they chose to include. Some systems, like the Packard Bell Legend had a 74 MHz processor coupled with only 4 Megs of RAM and installed on a 540 Meg hard drive. That all sounds good until you realize that Windows 95 really didn’t run well unless a minimum of 16 Megs of RAM were installed, 24 was even better. That particular system as sold was more suited for running Windows 3.1. The included “Packard Bell Navigator” would barely run at all. Only after spending more money to upgrade the system memory did the computer run as it was intended.
Which brings me to the subject of this article. If you’re one of those who have brought an old system back to life because of the continual costs of upgrading the PC to meet the minimum standards for the operating system, how far back did you go? Think about it. You can go all the way back to Windows 2000, Windows 98, 95 or even Windows 3.1. You could even go back to the days of DOS! Why not? Programs are all out there for the taking. You can download them onto your newest computer that is connected to the Internet, and with a little skill and know-how, you can save all these programs to be used on your older computer. Then gain, many of these old computers that folks are pulling from their garrage or storage room still work with the programming that was on them when they were put away up to and including 33 years ago.
Word processors for writing letters, or school reports; spreadsheet applications for bank records; and even database programs for storing recipes and other items. These programs can be just as useful as today’s’ counterpart.
Everyone who reads my blog knows I have been restoring and refurbishing an all original IBM PC system from 1984, complete with an IBM expansion unit. While most of you will never need an expansion unit, or for that matter, any computer as old as mine, I do have all of the programs I could ever want. Word Perfect, VisiCalc, Lotus123, and many, many more are in my software library. Most can be found by looking on the Internet, but you must be careful of the usual items when you’re looking for software. Viruses are more prevalent than ever before, and copy write protection is still in force on the majority of the software titles you find. It is usually best to purchase software from a known good vendor. But even those are getting harder and harder to find for very old software.
Another option is to look on abandon ware sites. These sites will have programs for which the copy write was never filed, or has run out, or for some reason makes the software available for free.
My point today is that vintage computing is a growing market. Prices have fallen as low as they are ever going to get, which I talked about in another article as well. Look for a computer you know will work for you, even if that computer is in your own garage. Break it out, set it up and start using it again. Who knows, you might even find an old game you forgot about.
Just like anything in the World, when it comes to collecting vintage computers, too much of a good thing can be a serious issue. If you’re just starting a vintage computer collection, whether it’s just one computer or several, you must be mindful of your goals. Now, these goals can change as time goes on, but stop every once in a while to really think about your investment. Why are you collecting? Are you simply trying to relive your old school days? Do you want to collect particular systems, or are you going to go broadscale and get everything you can from a particular time frame?
In my case, it started out simple enough. I wanted to get the same computer I used in college. Once I had it, and got a few upgrades to match as closely as possible to the system in my old college computer lab, I found that I wanted more. One very bad thing happened during my search for the perfect IBM PC. I saw mention of a piece of hardware that looked so simple, yet it turned out to be quite rare. The item in question was an original IBM 5161 expansion unit made specifically for the IBM PC. It was quite unfortunate that I saw that article. Because rather than being happy with owning the best possible specimen of an an IBM 5150 PC with dual floppy drives and 640 K RAM etc, I had to find an expansion unit too.
That began a year long search. Eventually, one became available, but at a cost. The unit I found had all of the major parts that made it a true IBM 5161. It had the passive 8 slot ISA back plane. It had the correct power supply, and cables. It even had the correct IBM badges. What the expansion unit lacked were the hard disk drives and controller. But the price was right at only $40.00. After shipping, the total came to $68.50. It took another two months to locate the proper controller and hard disk drives for the unit, and in the end, it all came together. Now the expansion is outfitted with an Intel 8/16 LAN adapter, modem, and a dual 9 pin serial port adapter. Normally those cards would have been installed into the main PC, but because of other expansion cards installed in the PC, these had to be added to the expansion unit. But also since the PC was never designed to have a hard disk drive installed, these also had to be installed into the expansion unit. There are other limitations to the 5150 PC, like the fact that it only has a maximum of 5 expansion slots, versus 8 in all of the next generation PCs like the 5160 XT. So adding the expansion unit for me was a great idea.
However, it didn’t need to be. The 5150 may not have been designed with adding a hard disk drive in mind, but by swapping out the power supply for a more powerful unit, a herd disk drive can be added to replace on of the floppy drives normally installed. Plus, by installing the right adapters, all 5 of the PCs internal expansion slots could have been used to provide all of the functionality gained by using the configuration I ended up with. There is one thing in my favor though. And that is value. All together, I have about $500.00 invested into this system. But this system is certainly worth more than the sum of it’s parts. I have been offered far more than $500.00 for the entire system as it is configured; enough so that if I had been inclined, I could have easily started over with another PC. The problem is that of rarity. There is a reason I am not selling this system. That is because the expansion unit by itself is worth a lot more than the PC simply because they are so rare. See, I got lucky and kept my eyes open for opportunity. These don’t come up for sale every day, and when they do, some of the most important parts are missing. None of the parts that make the entire system are missing. In fact, I was given a complete set of extender and receiver cards for connecting the PC and expansion unit together about 12 weeks prior to my locating the actual unit. The person I bought the unit from was missing the extender card. So, I made an offer. To my surprise, he accepted. It is the extender card more than any other piece that is missing from most of the expansion units found. And currently, there are no manufacturers making any to replace them. So that makes a working system complete with IBM PC and 5161 expansion unit worth all that much more.
The main point I wanted to make here is this. I could have, and should have been happy with the perfect IBM PC system. But because I knew of the expansion unit, I had to have one. The system certainly didn’t need it. But now that I have one, and everything works, I can’t just give it up so easily. Think of that as you begin restoring or purchasing your vintage computers or systems.
That’s all for today. As always, I hope you found this useful.
How would you describe your Dream Computer? Here is the tale of how Thomas got his.
At the time you got your first new computer home, did you call it fantastic, awesome, blah, stupid or even a pain in the butt? Well, here is a configuration Thomas would bet you would find pretty funny; especially in today’s age where computer systems have multiple Terabytes of storage capacity, dual and quad core processors running Gig’s of RAM. But you see, his dream computer isn’t a new computer, by any means. It did however make IBM the standard to which all other computer manufacturers must meet, or make better. “The Term IBM compatible” was there for a reason. Thomas’ dream computer was always an IBM 5150 Personal Computer with as many IBM branded peripherals as possible, and all the while, keeping the computer period correct as well. So you won’t see an old computer with a CD Rom where a hard drive would go.
What Thomas was talking about building was the absolute best IBM PC which could possibly purchased in 1984.
Below are the specifications for Toms IBM 5150 Personal Computer. This particular computer was originally manufactured, and sold in 1984. Everything you see below is how the computer was initially ordered. At the end, you’ll see some prices. Don’t cheat by looking ahead. We think you’ll be very surprised! Thankfully, Thomas didn’t have to pay for the computer, as it was one he used in college. In fact, it was the very first PC Tom had ever used.
Sure, there were others before the IBM Personal Computer, but none were nearly as important to computing history. The IBM 5150 Personal Computer set the standard for all others to follow. It was this computer alone, and IBM in particular who are responsible for the IBM Compatible movement, because after it’s introduction, other computer manufacturers had a crucial decision to make. Do they continue making their own brand, and their own idea of what a home computer should be? Or did they follow the pack and go with a proven strategy and build another IBM compatible? The answer was obvious. By manufacturing an IBM compatible, these computer builders had made the correct decision, not only for themselves, but for their customers who would eventually purchase one of two eventual competitors designs, and even then, Apple systems looked and felt much like the IBM systems they were trying to compete against.
So here are the specs for Thomas’ IBM Personal Computer. (At the end of this BLOG post, We’ll include another chart outlining the completed system.)
1. 8088 processor. In this case an Intel running a whopping 4.77 MHz
2. 384Kb Memory Expansion which brings the total system memory to 640Kb.
3. * 256Kb of memory installed on the motherboard using a series of 16Kb and 64 Kb chips.
4. ***No hard disk drive.
5. ** 2 – 5 ¼” floppy disk drives capable of writing Dual Side Double Density (DSDD) 360 Kb on a single disk, along with its floppy drive controller card.
6. No Mouse.
7. A keyboard that weighs over 10 pounds.
8. *** Cassette Recorder to load and save programs the computer user may have written in BASIC.
9. Color display adapter card that was capable of delivering CGA or 16Kb of video card memory. Maximum resolution was 640×200, supporting only 16 colors.
10. Graphics Printer that was really manufactured by Epson as their model Epson MX80. IBM contracted this printer and sold them under the IBM brand name for approximately $50.00 more than if the customer just bought the Epson branded printer. This was/is a dot matrix printer. It can print carbon copies, and multi part forms where multiple pages are printed at once, one on top of the other.
Memory initially supplied with the computer started at only 16Kb. This was upgradeable to 64Kb, but later models, from 1982 forward, came with 64Kb to 256Kb of memory as standard. Upgrades were available to maximize the memory to 640Kb through the use of expansion cards. IBM chose to offer their Personal Computer with no floppy drive for home users. In this configuration, customers would need to purchase a cassette recorder, or supply one on their own in order to save and load programs written in BASIC, which was included in the 5150’s ROM. However, the 5150 Personal Computer could also be purchased with either one or two internal floppy drives. However, that also required the additional purchase of an internal floppy drive controller.
A cassette recorder had to be purchased separately. The customer had to furnish their own because IBM never offered one. Customers had to buy one separately either from Sears, Computer Land, or other stores like Radio Shack. Prices for the recorder routinely ran about $39.95.
When Thomas purchased this computer in April of 2011, he had been looking for a computer. Not just any computer though. He wanted the very same computer I used in college. Thomas wanted the IBM 5150 Personal Computer, with all original keyboard, monitor and as many IBM labeled upgrades as possible!
When this computer was first built, sold and configured, it cost the original owner $5548.16. That was in 1983. By using the inflation calculator located at: www.dollartimes.com/calculators/inflation.htm; this particular IBM computer would sell for $12,459.43, in today’s dollars as of December, 2011! Luckily, Thomas didn’t have to pay over $12,000. he scoured E-Bay, Craigslist, and any number of pages on the Internet. Tom had just signed up and joined the Vintage Computer Forums, about a month before Tom planned on buying this particular model. He even made a few friends in the forums along the way. One such friend, who goes by the handle “Hargle” happened to see this computer for sale in a thread located in the Vintage Computer Forums, so Tom contacted the owner. They struck up a conversation and before long; made an offer of $200.00! The owner immediately accepted it and made arrangements for the computer’s purchase.
The only bad part of the entire deal is that the computers owner, and for that matter, the computer too; lived in Southern California. Tom lived in Las Vegas, NV. So, they put the deal on hold for a couple of days while Tom contacted his brother-in-law; who just happens to live about 20 or so miles away from the seller. While they waited to get hold of him, the seller had gotten several other offers, and a couple of them were actually higher than what Tom was willing and able to pay, but true to his word, they had a deal and both parties held up their end. So when Tom finally called and told the owner that his brother-in-law was willing to purchase the computer on Toms behalf, well, they had a done deal. Tom immediately forwarded the money to make it all happen. Tom’s wife was planning a trip to Southern Cal with her mother an just over two months, in June of 2011, so Toms brother-in-law held onto the computer at his home until they’re scheduled visit.
What did Tom buy? Well you know most of it. He got the computer, keyboard and monitor, all configured as explained at the beginning of this article, original boxes, and even original buyers invoice, and a small problem or two, but nothing serious. (We’ll discuss the problems later) For being almost 30 years old, this computer was, and still is, in fantastic condition. There are no signs of heavy use or any kind of abuse at all. Aside from some kind of ink and some dirt on the keyboard’s spacebar, the entire system was almost flawless. There are no nicks, scratches, dings, dents, and neither are there any signs of yellowing in the plastics. The computer looked like it had been boxed it’s entire life.
Electronically, and physically this is a fantastic example of an all original IBM 5150 Personal Computer. The only issue Tom ran into was in the form of money. While unpacking the computer, Tom and his Wife Kris, heard something rattling inside. They were both immediately worried that parts of the computer had come lose and were just floating around the bottom of the computers’ case. So they removed the cover, which had to be straightened because someone had tried to pry the cover off from the sides, not knowing what they were doing. Well, that was an easy fix, Tom just tweaked the case cover to bend it back into proper shape. Then with the top removed, they tilted the PC side-to-side and watched. To their amazement, they found some change. There was about 38 cents floating around the bottom of the case. So Tom and Kris got all that out and buttoned the computer back up.
After that, the computer ran fine when booting straight into BASIC. However, it was very intermittent when reading or booting from any floppy disks. The left or “A” drive would work most of the time, but the right floppy wouldn’t work at all. So, Tom contacted one of the friends he made on the Vintage Computer Forums named Chuck. They made arrangements for Chuck to completely clean and align both floppy drives. So the drives were sent to Oregon, and in less than 10 days, they arrived back home. Tom reinstalled them and gave them a good testing. Both drives worked great!
Tom’s friend, Edward Hall is the one person Tom trusts enough to take care of his “Baby”. In fact, when there is anything that needs to be added to the system, Tom calls Edward. Not just because Ed is Tom’s best friend, but also because Ed is one of very few computer technicians who know what they’re doing around these old machines. So when Tom wanted to upgrade the 5150 by adding in a game controller and a combination parallel/serial port card, there was only one place to go. Later Tom had one more upgrade he wanted, so he worked out a deal with another member in the Vintage Computer Forums to obtain an AST Six-Pack Plus card. He called Edward, who again came over to take care of the hardware change. Tom is a good technician in his own right, however, due to educational differences, Tom never saw the inside of a computer till 1995 when he purchased his first “Real Computer”; a Packard Bell Legend home computer bundle that came with a new upgraded monitor capable of 640 X 480 graphics at true 32 bit color, a 75 MHz processor and 4 Megs of RAM running Windows 95 installed on a 540 Meg hard drive. Those differences kept Tom from learning how to perform most of the processes for upgrading and repairing PCs until after 1995 when the operating system did most of the work of installing new hardware. So when it came time for things to be added to Toms IBM, of course he had no idea what steps to take.
Back on track, Tom credits his friends for getting his IBM 5150 PC running the way he wants it to be. In particular, Ed Hall for being there to handle the areas where Tom’s expertise is lacking.
Tom’s PC looks great and works perfect. This is the one computer Tom had envisioned and wanted ever since he first saw that first one in the college.
Pictured here is Tom’s IBM 5150 computer, complete with cassette recorder and 16 color CGA monitor.
Tom’s next project was a huge add on and a very rare piece of computer history; an IBM 5161 Expansion unit clone.
During the restoration process of Toms IBM 5150 PC, he ran into an article explaining the virtues of an IBM 5161 expansion unit. This piqued Tom’s interest to the point that he had to get more information. What he learned got him motivated into either trying to find one for sale, or building one on his own. Since original 5161 expansion units were so rare to begin with, Tom decided that he would build one from parts available to him through his resources.
The parts list for Toms version of the expansion unit was fairly long, having to include things like an 8 slot 8 bit Passive ISA Back Plane, 170 watt ATX power supply, expansion cards, hard drives and controllers. The price list including the case would also include very minor things such as expansion slot covers, full length expansion card guides, and a few other minor odds and ends. Tom expected to be working on the build for approximately 6 months. However, things change, especially well laid out plans.
In late January, a friend named Ole Juul, in the VCF had given Tom a complete set of extender and receiver cards for an IBM 5161 expansion unit. Ole gave Tom the cards with the understanding that they may work, but there was an equal chance that they wouldn’t. So Tom took them and paid Ole for the postage. The sole intention at the time of taking the extender and receiver cards was so Tom could begin building an IBM 5161 expansion unit “clone” using a discarded IBM 5160 case as a starting point. At least that was the plan. However, something happened in late March of 2012.
Tom fell into a great deal for an original IBM5161 Personal Computer Expansion Unit. A user in the Vintage Computer Forums web site had posted in the Wanted section that he was looking for an expansion unit extender card. So, since Tom had the complete set of transmitter and receiver cards, he offered to purchase his expansion unit. he wasn’t expecting anything to come of it, but you never know if you don’t ask. To his surprise the owner replied that yes, he would be willing to sell the unit. He did not know however how much to ask, so Tom initially offered him $150.00 in it’s current condition. When he got his reply a couple of days later, Tom was at first heartbroken. The owner of the expansion unit informed was refusing the offer, but he had a counter. Instead of $150.00, he would sell the expansion unit to Tom for only $40.00! With shipping, the total cost to would be only $68.50! Of course, Tom had to take it. Tom sent payment for the expansion unit that evening.
Tom thought I had made a fantastic deal. The seller told Tom that the unit currently had 2 SCSI drives installed, but he needed to keep those drives. The seller assured Tom that he would install an MFM controller and 2 MFM drives. He was also including “a selection of various expansion cards” to “sweeten the deal”
What Tom received about a week later was huge let down to say the least! When the package had finally arrived, Tom was elated. As he opened the box, the expansion unit was exactly described on the outside. There were no scratches, dings, dents or other damage, but there was also a large hole in the front of the case where a hard disk drive was supposed to be. Upon opening the unit, Tom and Kris discovered that the seller did indeed remove all of the SCSI equipment, but instead of installing 2 MFM drives, he only included one, with a broken Western Digital controller card. To top it off, the drive that was included was meant for an IBM AT computer, since it had no front faceplate. Later it was also discovered that the drive was also not in any kind of working order.
So, back to the VCF where Tom was able to post a new thread looking for a hard disk drive and controller card. Of course his friends on VCF came through, yet again. Chuck, (yes the same chuck who repaired the floppy drives earlier) replied that he had a controller and pointed Tom to an auction on E-Bay for a full height 10 Meg Miniscribe MFM drive that was due to close in less than a day. There were a few bids on the drive, but Tom decided to go for it. Toms bidding strategy worked wonders, and in less than a week he had the drive in his hands. He also had the controller that Chuck(G) put together and so, off to work.
Assembly of the expansion unit went very smoothly. That is until Tom got to the hard drives. The Miniscribe drive and Xebec controller worked out great. It was the IBM drive that was included with the expansion that gave the most trouble. (Tom didn’t know the drive was bad yet, and since putting it on E-Bay, had gotten no bids either.) First, the MFM cables weren’t long enough to accommodate connecting the 2nd drive comfortably. The ribbon cables had to be run underneath the drive bays in order to just barely reach the controller’s connections. And the IBM drive didn’t have a faceplate. So back to VCF. Tom contacted a couple more friends in the forums and bought an old MFM drive cage that still had it’s faceplate attached. Well, that wouldn’t work as is, so with a little modification, the faceplate was removed from the old cage and installed onto the front of the IBM drive. As seen below; it was a perfect fit!
When Tom powered on the system, everything spun up very nicely, so it was working; at least so far. But when the expansion unit was connected to the PC, there were immediate issues with the IBM drive. Plus, Tom had forgotten that he had listed the IBM drive for sale on E-Bay, and it just sold; for a good amount too. So the IBM drive was removed, the faceplate put back on the old drive cage, and the entire cage reinstalled into the empty drive bay to cover the opening on the front of the expansion. This time everything was a perfect fit. Without the second drive, the ribbon cables could ‘relax’ as they were meant to. The system even booted directly to DOS on the Miniscribe drive. Tom had a working expansion unit. But most importantly, the extender and receiver cards that Tom was given and which were so far were in questionable condition, were working just fine.
Tom went back into the forums when the money cleared his PayPal account so he could see if anyone had another drive for sale. True to form, Tom found another drive, and this time with a Western Digital controller. The member who sold the drive and controller pre-configured the controller so the installation is as ‘drop in and run’ as possible.
So, here’s where everything sits right now. The IBM PC has been upgraded with a new AST Six-Pack Plus expansion card and has been upgraded as far as Tom wants it to be. The expansion unit is going to be completed once the second hard disk and Western Digital controller card arrive. There were also some small advances in peripherals over the last weekend too.
Tom has a friend in Las Vegas who is also into vintage computing. His name is Ivan. Ivan is more into the Tandy Color Computer, or Coco, but still works with original IBM systems as well. Ivan brought Tom a small gift on his last visit. It is a dual 9 pin serial port card. Along with that card, Tom has an Intel 8/16 LAN adapter and an 8 bit modem that will be installed and configured at the same time as the drive and controller. Tom has planned it so that the system is opened as rarely as possible.
Tom is very proud of his all original IBM 5150 PC with IBM 5161 expansion Unit. The two pieces are now completely dependant on each other too, so that the PC cannot be booted if the expansion unit is not powered on itself. All of the time and effort that Tom has put into this machine has also prompted him to name her “Alice” after a derelict spacecraft found in a junkyard in a Star Trek Voyager episode. Below are the IBM’s completed specs and a couple of pics to show the set up Tom chose for his favorite computer.
1. IBM 5150 PC with 8088 Processor with original PC/XT Keyboard
2. dual 5.25″ floppy disk drives
3. IBM Floppy disk controller
4. IBM 5153 CGA Video Monitor
5. IBM CGA Color Video Adapter Card/Parallel port – LPT1
6. AST Six Pack Plus expansion card with the following
A. 384 Kb Memory expansion (which increases total system memory 640 Kb.)
B. Asynchronous Serial port
C. Parallel Port – LPT 2
D. Game Controller Port
7. IBM 5152 Graphics Printer – (on LPT1)
8. Radio Shack Optimus CTR-109 Cassette Tape Recorder
9. iOmega Z100P2 100 Meg Parallel interface Zip Drive – (on LPT2)
10. Expansion Unit Extender Card (For connecting the expansion unit to the PC)
11. IBM 5161 PC Expansion Unit
12. 1 – Miniscribe 2012 – Full Height MFM Hard disk Drive – 11 Meg Capacity.
13. 1 – Control Data Full Height MFM drive.
14. 1 – Western Digital MFM Controller Card
15. Expansion unit Receiver card (For connecting the expansion unit to the PC)
16. Intel LAN Adapter
17. 3Comm 28.8 or 33.6 Data/Fax/Voice modem.
18. Serial Mouse
19. Dual 9 pin Serial Port Card
20. Manual – IBM PC/XT Guide to Operations
21. Manual – IBM PC BASIC
22. Manual – IBM Disc Operating System 3.3
IBM 5161 Expansion Unit with extender and receiver cards, which by using a special cable designed just for this purpose,
connects the two machines together. This in effect makes them “One Piece”.
What began as an ongoing project is almost complete. There are still a few things that require work, but Toms has friends. Tom thanks them every day he looks at the system.