Build your own IBM PC 5150 clone - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: September 29, 2016, 11:53:34 pm
content: Order the kit from here:http://www.mtmscientific.com/pc-retro.htmlThere is a video by Computerphile about this kit

author: Tomorokoshi
author_rank: Super Contributor
timestamp: September 29, 2016, 11:56:25 pm
content: About 20 years ago where I worked there was a new, unused 8088 motherboard in an anti-static bag in the junk pile. I should have taken it.

author: dannyf
author_rank: Super Contributor
timestamp: September 30, 2016, 10:27:35 am
content: years ago, i used and sold some nec clones of the 5150.does anyone have the original ps/2?ibm's reasoning behind the use of smts there was laughable, looking back.

author: Halcyon
author_rank: Unknown
timestamp: September 30, 2016, 10:32:20 am
content: Quote from: dannyf on September 30, 2016, 10:27:35 amNot an original. I've got an IBM PS/2 Model 30 8530 on the desk next to me. 10MHz 286 with a 20MB hard disk. I loved this particular model because it was one of the ones which have ISA slots, not that bloody MCA rubbish.

author: StuUK
author_rank: Frequent Contributor
timestamp: September 30, 2016, 11:31:33 am
content: Quote from: Halcyon on September 30, 2016, 10:32:20 amMCA, technically superior apparently but subject to IBM licensing so never popular beyond IBM kit and always expensive compared to the ISA equiv.

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: September 30, 2016, 12:51:27 pm
content: the problem is with that project from mtm scientific, you need an original XT case as the ISA slot width was different to what became standard later with at/atx casing. only original XT cases fit this board.I built this,http://www.malinov.com/Home/sergeys-projects/xi-8088its an 8088 xt board, basically an 8088 sbc, fits in 8bit isa slot. very cool, easy to make.

author: dannyf
author_rank: Super Contributor
timestamp: September 30, 2016, 02:13:15 pm
content: Quotelike VHS vs. betamax: what's popular isn't necessarily superior.

author: rrinker
author_rank: Super Contributor
timestamp: September 30, 2016, 05:23:50 pm
content: My first MS-DOS computer was very much like that computer on an ISA board design, there was no motherboard, just a card slot backplane, and the main system was on one card with the memory and some other stuff on a second card. One extra switch on the back of the CPU card toggles between 8MHz and 4.77MHz operation for running timing dependent programs. I later enhanced it with an 8087 math corprocessor (really sped up PSPICE simulations) and a NEC V20 CPU.

author: alank2
author_rank: Super Contributor
timestamp: September 30, 2016, 05:48:50 pm
content: That is interesting; I didn't know there were PC compatible computers that had a backplane instead of a motherboard and the cpu was on a card.

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: September 30, 2016, 06:03:52 pm
content: Quote from: alank2 on September 30, 2016, 05:48:50 pmmy Xi8088 is basically an XT with a backplane, I also have a 486 in a backplane. These are more or less 'industrial' control stuff, even tho its no different from sitting on your desktop, but the isa backplane evolved into the PICMG stuff which is like a PCI slot tacked above an ISA slot. you can get modern day cpu on these cards for backplanes.you can see my xi8088 project log and my 80486 log on my projects page;http://kråketær.com

author: Kjelt
author_rank: Super Contributor
timestamp: September 30, 2016, 07:09:12 pm
content: About fifteen years ago there were about 50 of the original ibm xt or at computers in a container outside in the rain of a metal scrapyard. I asked and they wanted around 10 euros a piece. I thought hard and could not figure out what to do with them except for nostalgia. I went home with an empty trunk and still do not regret it. What on earth would you seriously consider using it for today?

author: raptor1956
author_rank: Frequent Contributor
timestamp: September 30, 2016, 08:13:24 pm
content: Quote from: Kjelt on September 30, 2016, 07:09:12 pmAs a memento to a time when IBM was more than a consulting firm with some legacy hardware/software. Actually, the IBM PC marks a demarcation in time -- before IBM was the leader and pioneer of the computer industry and after ... not so much. By the late 80's Bill Gates, when asked about his relationship with IBM said, "IBM is irrelevant!"Brian

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: September 30, 2016, 09:10:49 pm
content: Quote from: Kjelt on September 30, 2016, 07:09:12 pmwhy do people collect anything retro or vintage? we get some enjoyment from it.

author: Kjelt
author_rank: Super Contributor
timestamp: September 30, 2016, 10:00:10 pm
content: Yes i can understand collecting the original , collecting retro, but this topic was to build a replica a clone which has no collector value of any kind? The only reason to buy and build one is or for the hobby to solder something or for someone to actually use it for something. I was wondering what that would be?

author: Halcyon
author_rank: Unknown
timestamp: September 30, 2016, 10:11:57 pm
content: Quote from: Kjelt on September 30, 2016, 10:00:10 pmFor shits and giggles. It's not really designed to be a collectors item and not everyone can afford to buy a used IBM PC (original or otherwise) and even though you're basically just following the silk screen it's still nice to build something yourself. It'd be great for young players, it gives an appreciation of how far we've come with computing.

author: eugenenine
author_rank: Frequent Contributor
timestamp: September 30, 2016, 10:38:37 pm
content: Quote from: BloodyCactus on September 30, 2016, 12:51:27 pmThe original PC was 1" spacing between the ISA slots, the XT was the now standard 3/4".In 1994/1995 built a CNC PCB router using an XT mainboard that I paid $10 for .I might have to build one of those boards to put in the slots of my Amiga 2000

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: October 01, 2016, 12:06:02 am
content: Quote from: eugenenine on September 30, 2016, 10:38:37 pmyes, the 5150 with 5 slots is not standard isa slot spacing. that came later with the xt, 5160.you need a 'bridgeboard' for your amiga. they are an SBC that plugs into the zorro slot that also connects to the isa slot.. (incase you did not know what a bridgeboard was.... I dont think many amigans had them)

author: nctnico
author_rank: Super Contributor
timestamp: October 01, 2016, 02:16:41 am
content: Quote from: BloodyCactus on September 30, 2016, 12:51:27 pmWhy isn't there an FPGA on that board?

author: joeqsmith
author_rank: Super Contributor
timestamp: October 01, 2016, 06:08:21 pm
content: Quote from: raptor1956 on September 30, 2016, 08:13:24 pmI still have my old 5150. Dusted it off to run Trixter's 8088mph demo.http://www.vcfed.org/forum/showthread.php?47084-Trixter-s-latest-magic-Holy-how-in-the-hell!!!&s=99c622b4cd72a8e59de449fdae0a1e35&highlight=8088mph

author: joeqsmith
author_rank: Super Contributor
timestamp: October 01, 2016, 06:15:05 pm
content: Someone had posted this link to help identify the various versions of the 5150. Mine appears to be a mid version with the black supply with red label but five screw case.http://minuszerodegrees.net/5150/early/5150_early.htmAttempting to turn the thing on after many years.....

author: eugenenine
author_rank: Frequent Contributor
timestamp: October 01, 2016, 11:53:31 pm
content: I wish I hadn't gotten rid of mine, but when the city turned our neighborhood into a ghetto we had to move and I had to get rid of a lot of stuff.

author: Halcyon
author_rank: Unknown
timestamp: October 02, 2016, 03:38:07 am
content: Quote from: joeqsmith on October 01, 2016, 06:15:05 pmThanks for posting that! What a cool machine. Looks like it's in great condition.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 02, 2016, 04:30:09 am
content: I doubt it's worth anything to a collector but I have fond memories of playing with these computers when I was younger. This was a board I had designed for the IBM-AT that I then wrote some software to do some speech recognition.

author: Bicurico
author_rank: Super Contributor
timestamp: October 02, 2016, 10:30:20 am
content: When I saw the kit, my first reaction was: COOL - I WANT TO HAVE THAT!But then......I looked at the price of the kit: US$ 150 excluding shipping and customs to EU.And then, thinking further about this:- no power supply- no graphics card- no keyboard- no monitor- no disk drivesHmmm...Guess it would be MUCH cheaper to just buy an IBM XT on eBay, do I did a quick search and you can get the original 5150 from 150-900 Euro in working condition. At 150-200 Euro you get the working computer with disk drives, the one at 900 Euro was complete in mint condition with monitor.And then I wondered: why bother? Just run DOSBOX or visithttp://www.pcjs.org/...So basically, my excitement lasted about 10 minutes. But thanks to the OP for the memories!Regards,Vitor

author: eugenenine
author_rank: Frequent Contributor
timestamp: October 02, 2016, 02:01:14 pm
content: Space issue also. I don't have a place to put an XT and monitor and keyboard. Most of my computers are Raspberry Pi's running headless to save space.

author: joeqsmith
author_rank: Super Contributor
timestamp: October 02, 2016, 02:14:21 pm
content: Over a $1000 USD for a 5150??!!Looking on ebay, prices seem really high. From what I remember, I think the BIOS in mine was too old to support reading the external ROMs. Asking price of the boards is also really high.

author: boffin
author_rank: Unknown
timestamp: October 02, 2016, 03:19:44 pm
content: Quote from: eugenenine on September 30, 2016, 10:38:37 pm

author: alfondo
author_rank: Newbie
timestamp: February 09, 2017, 07:01:09 pm
content: Hello,QUESTION ABOUT HOW TO INSTALL TWO COMPONENTS on IBM 5150 KIT ( sold inhttp://www.mtmscientific.com/pc-retro.html)I have installed every component of the motherboard but two elements, which im not sure how it should be done. There no explanation or image that shows how to solder them into the motherboard. I have the image of the two components and their place on the motherboard.It would be awsome if someone can help me with that.Cheers!

author: Cubdriver
author_rank: Unknown
timestamp: February 09, 2017, 07:20:49 pm
content: Quote from: alfondo on February 09, 2017, 07:01:09 pmLooking at your photo, it appears that the trimmer cap should go in pretty much as you have it oriented - the extended terminal goes into the hole at 3:00, and the two that are close to the body (and common) go into the other two holes to the left.The crystal leads are bent 90 degrees to the body and go into the holes to the left of the rectangle on the silkscreen, and the crystal is laid on its side in that rectangle. A piece of wire is then run over it and soldered into the two holes (above and below the silkscreened rectangle) to hold the body down, sort of like a seat belt.-Pat

author: Cubdriver
author_rank: Unknown
timestamp: February 09, 2017, 07:28:30 pm
content: A similar crystal mounting scheme from a google image search - this shows a cylindrical crystal package, but the idea is the same.The leads from the crystal should go into the round and square pads above the 'VC1' label on your board.-Pat

author: james_s
author_rank: Super Contributor
timestamp: February 10, 2017, 01:32:11 am
content: I still have an original IBM PC/XT, pretty well decked out with an EGA card driving an IBM CGA monitor. Nice collectible system but I should probably sell it. It's historically significant and fun to play with but it takes up too much space and it isn't all THAT unique compared to modern PCs. I have other vintage computers in my collection that are far more interesting to me, Amiga, a few old 68k Macs, Sun workstations, and some FPGA based retro systems.

author: eugenenine
author_rank: Frequent Contributor
timestamp: February 10, 2017, 02:36:56 am
content: I had to leave my XT when we had to move years ago. I had two memory cards, a 10M hdd and an old 10b2 nic which I could actually get on the internet with a doc tcp-ip stack and lynx.Still have an Amiga 2000 I need to fix some day

author: james_s
author_rank: Super Contributor
timestamp: February 10, 2017, 07:00:48 am
content: Quote from: eugenenine on February 10, 2017, 02:36:56 amHopefully you've removed the battery by now. These have a 3.6V Varta NiCd soldered to the motherboard, it leaks and damages the motherboard. I had to replace the CPU socket and a number of other parts on a A2000 recently, it's a bit of a job.

author: eugenenine
author_rank: Frequent Contributor
timestamp: February 10, 2017, 11:52:17 am
content: I did replace it but it had already leaked when I got it. I had been regretting selling my A500 for so long I watch the local craigslist for Amiga and picked up this 2000 last summer. I just need to fnid the time to dig into it.

author: alfondo
author_rank: Newbie
timestamp: February 10, 2017, 06:27:44 pm
content: Cool! Thank you very much!!!I have done it that way. I attach photo so you can see it.

author: alank2
author_rank: Super Contributor
timestamp: February 10, 2017, 06:32:52 pm
content: I do have to wonder how long it will be until someone does a FPGA style version of something like this. It seems like I saw a page where someone put everything but the CPU in FPGA and ran it alongside an 8088 or 8086 or something.

author: Cubdriver
author_rank: Unknown
timestamp: February 10, 2017, 06:43:59 pm
content: Quote from: alfondo on February 10, 2017, 06:27:44 pmGlad to help - looks good!Let us know how you make out getting it up and running.-Pat

author: eugenenine
author_rank: Frequent Contributor
timestamp: February 10, 2017, 06:45:20 pm
content: Quote from: alfondo on February 10, 2017, 06:27:44 pmIIRC aren't you supposed to bond the wire to the crystal case to ensure its grounded (noise immunity).

author: helius
author_rank: Super Contributor
timestamp: February 10, 2017, 07:05:11 pm
content: Yes, I've seen the wire tacked to the case, but as an additional assembly step it's often skipped.

author: james_s
author_rank: Super Contributor
timestamp: February 10, 2017, 08:46:15 pm
content: Quote from: alank2 on February 10, 2017, 06:32:52 pmAlready done, sort of. Check out the Zet CPU, it's not a clone of the 5150 but it is a PC clone running MSDOS on a FPGA.

author: alank2
author_rank: Super Contributor
timestamp: February 11, 2017, 02:15:10 pm
content: Quote from: james_s on February 10, 2017, 08:46:15 pmThat is interesting. I guess what I wonder is with all the Atom's and other small cheap SBC's, is there something that would work well for a DOS machine that has some modern ports and some legacy ports [that work in DOS]. You could get by on VGA still, but HDMI would be ideal. You would want USB keyboard/mouse. A real parallel and serial port that work in DOS would be a must. Does anyone know of new products that fit this?