Build your own IBM PC 5150 clone

[joeqsmith]

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. 

[boffin]

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-8088

its an 8088 xt board, basically an 8088 sbc, fits in 8bit isa slot. very cool, easy to make.

Isn't the XT 0.8"  ?

The 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

[alfondo]

Hello,
QUESTION ABOUT HOW TO INSTALL TWO COMPONENTS on IBM 5150 KIT ( sold in http://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!

[Cubdriver]

Hello,
QUESTION ABOUT HOW TO INSTALL TWO COMPONENTS on IBM 5150 KIT ( sold in http://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!

Looking 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

[Cubdriver]

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

[james_s]

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.

[eugenenine]

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

[james_s]

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

Hopefully 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.

[eugenenine]

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.

[alfondo]

Cool! Thank you very much!!!
I have done it that way. I attach photo so you can see it. 

[alank2]

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.

[Cubdriver]

Cool! Thank you very much!!!
I have done it that way. I attach photo so you can see it. 

Glad to help - looks good!    Let us know how you make out getting it up and running.

-Pat

[eugenenine]

Cool! Thank you very much!!!
I have done it that way. I attach photo so you can see it. 

IIRC aren't you supposed to bond the wire to the crystal case to ensure its grounded (noise immunity).

[helius]

Yes, I've seen the wire tacked to the case, but as an additional assembly step it's often skipped.

[james_s]

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.

Already 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.

[alank2]

Already 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.

That 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?