40th anniversary of the IBM PC 5150

[andy]

You have a modern system with a floppy?

This particular one is an AMD Athlon 64 X2, so not exactly modern, but modern enough to still run the latest Windows version. There are more modern systems with floppy controllers, and other ways to emulate a floppy, but I didn't want to spend all day on this.

The point is that I think it's interesting that you can boot the very first DOS version for the IBM PC on the same system that also will run the very latest version of Windows even though the two operating systems were made 40 years apart.

 

[Eudimorphodon]

Now I'm curious if any USB floppy drives can read an 8-sector disk. I don't at the moment have the necessary hardware to generate such a disk to test wired up...

 

[krebizfan]

Now I'm curious if any USB floppy drives can read an 8-sector disk. I don't at the moment have the necessary hardware to generate such a disk to test wired up...

The YE-DATA USB floppy manual I have claims that it can read the PC98 640KB disk format which is an 8-sector format. Doing that requires the use of the Win98 specialized driver. I don't have the drive so I haven't been able to verify it.

 

[voidstar78]

The point is that I think it's interesting that you can boot the very first DOS version for the IBM PC on the same system that also will run the very latest version of Windows even though the two operating systems were made 40 years apart.

Agree on that, but I suppose some would argue we've sacrificed a lot (of innovation) by catering so much to backwards compatibility. Sure, certain things may have progressed a little slower (multi-tasking OS), but to me I do think it's been admirable progression - like Windows eventually handling long filenames vs DOS 8.3.

But yes, pretty cool that an original binary still runs natively on modern equipment decades later. It's like an old-windmill that's still operational centuries later

 

[framer]

The following are images of #117425 believed to be from the 1st batch shipped. There are differences after that release. It's still is turned on weekly and works perfect. This is a Model A w/16-64K systemboard. When I got this 10+years ago it still had the original 5700051BIOS installed. Bios has updated and the original is put away. I have the IBM v1.10 DOS and CPM software for it


This system had unbranded single side floppy drives.



Notice the extra port above the serial number.



A brownish power supply not black with fan nut raised off the surface, single sided floppies.



A metal speaker bracket.



Wide rear brackets, black in color.



Playing MS Flight Sim 1.00

Thanks for reminding me how old it is.

framer

 

[Maverick1978]

So the way I've decided to celebrate the 40th anniversary is to begin my "dream" project: building up a 5150 clone kit and all accompanying ISA cards from scratch, and stuffing it all into an empty 5150 case I've had for a few years.

I bought a kit from MTM Scientific, I have an XT-IDE v2 PCB purchased here some time ago to cover HD and Serial, I have Sergey Malinov's Floppy controller and Adlib clone PCBs, and I've 1mb and 2mb EMS PCBs from TexElec. I've also got a NOS 360kb floppy drive from CR, and I'll modify a STL file for a hard drive plate cover if need be to hold a Gotek and CF mount.

I've still got to get a Snark Barker PCB, and I'm still hoping to find a non-VGA display card PCB somewhere (I know of the graphics gremlin from Tube Time, and it's amazing, but I believe that it's soldering is a bit beyond my skill set, let alone the price of an FPGA-driven card). As I've Mono/CGA/EGA monitors here, I'm hoping to find one of those. If worse comes to worse, I've a NOS Paradise EGA card that could be used in the meantime.

I've still got to find an appropriate red-switch power supply for it as well.

But... details That's part of the fine.

All in all, this will end up being probably the most expensive retro PC that I own.... but it'll be all custom-built by me. How cool is that!?

 

[voidstar78]

framer Thanks for sharing those shots of the "model A". Nice metal bracket for the speaker! I wonder if they borrowed that from some other equipment, before spec'ing out the plastic one.

And that Circus Maximus shaped port above the keyboard/cassette connections - that'd be pretty useful. In setting up HXC drive emulators, you need to power them. I'd be handy to use that port to route some Molex or similar type cables. Does the plate comes out easily or is it semi-welded and you have to flex it out?


And wonder why they bothered painting the expansion plates black. That was a short lived precedence Maybe they just found a huge stash of painted plates and just used those till they ran out.


Do you happen to have a power cable from the 63W power supply that goes to a monitor? I've been curious - if you weren't powering an MDA monitor, would it be fairly safe to then power a physical/mechanical hard drive instead?

 

[jafir]

The power for the monitor isn’t calculated in the 63 watts, considering it is rated to draw 95 watts all by itself. It’s just passes through a/c power. There is a limit, but it’s not 63 watts.

 

[Eudimorphodon]

As long as you don’t go plugging a welder or something into it you’re probably fine.

 

[framer]

framer

And that Circus Maximus shaped port above the keyboard/cassette connections - that'd be pretty useful. In setting up HXC drive emulators, you need to power them. I'd be handy to use that port to route some Molex or similar type cables. Does the plate comes out easily or is it semi-welded and you have to flex it out?

Do you happen to have a power cable from the 63W power supply that goes to a monitor? I've been curious - if you weren't powering an MDA monitor, would it be fairly safe to then power a physical/mechanical hard drive instead?

The Circus Maximus shaped port is plastic and can easily be removed.




I have several adapters the allow you to attach two standard cords to external devices from the monitor port.

framer

 

[framer]

Another thing I just thought of, the front white bezel attached to the top cover was different than later models. When I went to clean it I started to remove paint they used way to easy. and changed my cleaning methods to not do more harm to it. The plastic exposed is very shiny and the paint did not adhere well to it. Later models were much more durable.

 

[voidstar78]

For reference, I came across this note at the IBM site...
https://www.ibm.com/common/ssi/rep_c...068/index.html

Basically it points out the substantial changes to the 5150 available around March/April of 1983. I've been calling it the "Model B" - but IBM used these terms: "The new Models 114, 164, and 174 replace the IBM Personal Computer Models 14, 64, and 74, which are withdrawn from marketing, and the Model 104 replaces the Model 1, which was withdrawn from marketing earlier." Yet there is no actual marking inside or outside to indicate these models? (so it's more of a "build configuration"?)


Lots of interesting things at the end of the article, for prices (yeah, those disk drives weren't cheap!). While the top of the article talks about the new 256KB model 5150, it's not clear from the prices at the end (all the 5150 models are listed with 64KB) -- but there is that 350$ 256KB RAM package (is that meaning filling up the banks on the mainboard? it's not talking about some RAM expansion card, right?)


Which BTW, did they keep making/selling 5150s by '83 as a lower price point option? (they're basically an XT without a HDD? or was the XT clocked higher, I can't remember?) Or did they just have lots of extra inventory to sell?


(anyone recall the machine that was used in the movie Electric Dreams? It wasn't an IBM PC - but still, it shows that idea of ordering a PC and then it became self aware, yeah 8-bit A.I., just add alcohol - haha)

 

[Eudimorphodon]

Which BTW, did they keep making/selling 5150s by '83 as a lower price point option? (they're basically an XT without a HDD? or was the XT clocked higher, I can't remember?) Or did they just have lots of extra inventory to sell?

So far as I'm aware IBM kept making 5150's as late as 1987, when they were officially withdrawn from marketing the same day as all models of the 5160 XT. (April 2nd 1987.) Some IBM documentation actually suggests you could still buy one under the table as late as 1989. A month later than a 5160, no less.

Why IBM bothered to continue making them that late, well, your guess is as good as anyone's. Initially when the XT was released in 1983 it was only sold with a hard disk, making its entry price much higher than the 5150's, but IBM started selling floppy-only versions in 1985. You'd think that would render the 5150 moot, but apparently IBM thought otherwise. My theory is that because of the arcane way corporate and government customers write purchase orders and specifications the 5150 continued to stick around well after its best-by date for strictly bureaucratic reasons.

 

[Exceter]

Interesting that the capacitors are blue instead of the usual yellow. Generally, I assume things with blue capacitors are a clone.

 

[krebizfan]

Upgrading the memory on the 5150B was done by buying the 64K Memory Module Kit priced at $165. The $350 product was the 64/256K expansion card product seen http://www.minuszerodegrees.net/5150_5160/cards/5150_5160_cards.htm#64_256_adapter In IBM speak, an option or adapter is a card while a kit modifies motherboard or card.

Looking at Oct 1983 PC Magazine, the price for a Quadram memory expansion card was $325 with 64K and $550 with 256K. IBM's prices for RAM chips were a bit high but I believe included installation and testing.

The 5150 had more room between slots so some who wanted cards with daughter boards might prefer it.

 

[T-R-A]

Interesting that the capacitors are blue instead of the usual yellow. Generally, I assume things with blue capacitors are a clone.

Most things happen that way due to price/availability. You wouldn't believe the number of times I've mistaken a SMD black with silver capacitor for a SMD diode. It's just what the manufacturer can get and how inexpensive they can get it.

 

[Eudimorphodon]

Looking at Oct 1983 PC Magazine, the price for a Quadram memory expansion card was $325 with 64K and $550 with 256K. IBM's prices for RAM chips were a bit high but I believe included installation and testing.

Is that list price for the Quadram? There's an ad on page 93 of that magazine that lists a 256k "Quadboard", which in addition to the memory includes parallel and serial ports and a clock, for $429, which appears to be about going rate for a third-party 256K multi-function board. (The next ad in the magazine actually lists a 256k+serial only card from Seattle Computer for as low as $325. And going the other way you could get a 384k or 512k board for under $600.) Not only is that a pretty significant chunk off IBM's prices (256k for little over the price of IBM's 64k) going with one of the parallel/serial/clock cards leaves you with two open slots in your CGA 5150 instead of the *zero*IBM's option cards would leave you.

(Also buying IBM's serial and parallel cards separately would be $120 and $150 respectively on top of the separate memory card, which really makes the IBM prices look bad.)

Edit: Wait, though, are we comparing the prices in the April 28th IBM announcement to October's PC Magazine? Maybe June... (edit again! ) No, wait, April is there in Google's archive too, that would be a fairer comparison... and, eh, doesn't make that much difference. Add about $50-100 to the third party prices. Also maybe of note, IBM was charging over $529 for a double-sided disk drive in that April price list, the third-party going rate was closer to $250. There's a reason that whole gray market thing was a thing.

 

[krebizfan]

I used the pricing from Quadram's back section business card style ad. I didn't want to deal with comparing discounted prices with IBM list prices when I know IBM could be discounted as well.

I am surprised by how much just having a bare card with bus interface cost; I didn't remember it being that expensive. Adding a serial port to a memory card cost basically what the serial port controller and port connector did. Most other companies would have designed a cost reduced PC and expansion cards to take advantage of the newer cheaper components on the market in 1983 or 1984. IBM's design was a bit cautious in 1980 but bordered on obsolete in 1986.

 

[framer]

I remember those prices, kept me grounded a couple of times just to buy memory chips.

 

[Timo W.]

Need to get a better dust-cover, however.

Fixed. Had some insane luck lately finding this perfectly-fitting dust cover and some other great retro stuff. :D