PS2 Type 8555 or : What kind of graphics adapter is this ?

[Alrik Fassbauer]

Hello everyone,

15 years ago or more, I had bought an old "microchannel IBM PC" on a flea market.
It was sitting around there in the attic for years since then.
Now I've finally come to dig it out and I want to make it run.
It turned out to be an "PS/2 Type 8555", according to its back panel.
But, alas ! - it doesn't seem to have a standard VGA adapter ???

Therefore I'm asking the forum : What the heck is this ???
My standard VGA cables don't fit into that, because there's a pin hole missing.

I made photos of that, and I wonder whether anyone can help me ? I fear already that i need to dig for a special cable somewhere, since I do not want to destroy the - seemingly - superflous pin on my standard VGA adapter cable.
One can barely see a few numbers there, a 15 on the lower left, 11 on the lower right, a 5 or 6 on the upper left, side, it seems to me. A 6 on the right middle row, and perhaps a 1 above that.
Where the missing hole is, there seems to be something, but I cannot read it.

Has anyone an idea ?

Alrik

P.S. : On the front side it looks almost identical to that picture I found in Wikipedia :

Personal System/2 – Wikipedia

de.wikipedia.org

The difference is that the switch has no colour, and it doesn't look as "fresh" as the one in the Wikipedia picture.

 

[Couchpotato]

Hmm I remember using PS2 keyboards and mouse before they switched.

You'll probably need an adapter for ps2 to vga.

Amazon.com : ps2 to vga

Or maybe a cable?

Amazon.com : ps2 vga cable

 

[Alrik Fassbauer]

Thanks so far, I'll do some more research.
What really bugs me is the missing pin hole. My standard VGA cable has a pin there where the hole is missing, so it doesn't fit in there.
I already have everything else, including PS/2 keyboard & mouse.

 

[Stingray]

I made photos of that, and I wonder whether anyone can help me ? I fear already that i need to dig for a special cable somewhere, since I do not want to destroy the - seemingly - superflous pin on my standard VGA adapter cable.

Weird, the "filled pin" on the VGA connector almost looked like someone filled it in, rather than being manufactured like that. I guess maybe that's because there's lettering there? (you said you couldn't read it).

On Wikipedia, the VGA pinout says that pin is used as a 5V power supply for the EDID chip on monitors. But monitors back then didn't have EDID. And it also says that pin 9 used to be a "key" pin, which would mean it was filled intentionally to prevent someone inserting a plug into it that had that pin (ie: to stop plugs being inserted backwards, although that would be difficult due to the metal ring around the VGA connector).

I think you'd be fine to just yank that pin out of a VGA cable you have and go.

 

[Stingray]

Note, I wouldn't yank that pin on a builtin cable of a monitor you care about. Make sure it's a VGA cable that's removeable on both ends. For use on modern systems you'd still want EDID to work, assuming it still does rely on that pin's 5V power.

edit: also I found a legit PS/2-era IBM VGA extension cable on eBay and it's indeed missing that pin:

IBM PS/2 VGA Monitor Extension Cable HDD15 MTO F MOLD TYPE W/TS 6ft NEW.SEALED | eBay

Find many great new & used options and get the best deals for IBM PS/2 VGA Monitor Extension Cable HDD15 MTO F MOLD TYPE W/TS 6ft NEW.SEALED at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Alrik Fassbauer]

Thanks, looks as if I need to open that computer case and take a closer look at it.

I have very vaguely a memory of some special kind of adapter having one pin less, but that memory ? is so blurry that I'm not sure whether it's real or I'm imagining something ...

 

[Stingray]

Thanks, looks as if I need to open that computer case and take a closer look at it.

I'm pretty sure all you need is to yank or break that pin (pin 9) off one end of a VGA cable, and you should be good to go. You don't need to do anything with the computer-side connector.

Or I guess you could look for a 35-40 year old cable that is already missing the pin. Assuming your monitor has a removable VGA cable (obviously anything modern does, but I don't remember about the 80's).

 

[Alrik Fassbauer]

The funny thing is, if you look at the "plugs" there

https://www.amazon.com/-/de/dp/B000067SP1/ref=sr_1_5?dib=eyJ2IjoiMSJ9.HhnyX9w12cQ7mVQc9dJtB74RqdwiADhULWCe8PcKSZSnPj_8lFb32aIO7ISFVBVBbki2es-uXKwkV8RAqtsDcrcMQtXqhVao3DsTu2TumS4hpJH3Bs3BzC6Gav3t_L_jp283HLq_3iELjidRWkKfO6Sb4UGzz45hBBpP_eQPhVh7JmpnIo4aG3uKK6UmDVqduVBqYNUe5jjRbuZJd-Lc0lqHdt2jQBtI6ZvrwWTzHmc.MQy_ADLjM9FXZDZZZjZrqYmRAUf3i2hPEOsmcqakxuk&dib_tag=se&keywords=ps2%2Bto%2Bvga&qid=1744969519&sr=8-5&th=1

it does show on one side a pin missing ...

 

[Stingray]

VGA Cables 14 vs. 15 Pin Cables [14 pin ver] | StarTech.com

Why does this VGA cable not have pin 9 while others do have it?

www.startech.com

That article almost makes it sound like VGA cables that are missing that pin are more common than cables with the pin. But I don't know, the new'ish VGA cable I have in my closet has the pin. Maybe it was written decades ago.

 

[Stingray]

But I guess it means that you should be able to find what you need by just searching for a "14 pin" VGA cable to buy.

 

[Alrik Fassbauer]

I have found another one :

ROLINE VGA Monitor-Anschlusskabel HD15 ST/BU, 10 m kaufen

Schnelle Lieferung ✓ Große Auswahl an %brandid% Produkten » Jetzt einfach bestellen: ROLINE VGA Monitor-Anschlusskabel HD15 ST/BU, 10 m

www.conrad.de

I think I need to look whether I have a cable of that sort, otherwise I'll buy that one.
Conrad Electronics is a German electronics shop where I went to sometimes years ago.

I wonder whether "HD15" is the keyword ?

 

[Stingray]

Nah, HD15 just refers to the particular 15-pin D-sub connector that is used for VGA. You still need to ensure that the one you're buying is a 14-pin cable (like the one you linked) and not a 15-pin cable.

 

[Stingray]

Also FYI, VGA monitor cables are male on each end. That one you linked is an extension cable.

 

[Alrik Fassbauer]

Oh. Thank you. Yes, I remember it now.

 

[Alrik Fassbauer]

I have found now that - seemingly - the local electronics shops also sell these 14 pin cables. I'll take a look at that tomorrow, if I can.