UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Computers

Notices

Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

Closed Thread
 
Thread Tools
Old 18th Jul 2007, 11:54 pm   #1
Michael Maurice
Moderator
 
Michael Maurice's Avatar
 
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
Default Vintage computer IBM System 2 850 3002

Hi, A customer of mine has asked me to look at a vintage IBM monitor that has gone wrong. It is an IBM System 2 850 3002.

The monitor is black and white, I cant remove the back because the two top 'screws' are non standard, or are they sockets?

The other thing is that the D connector of a modern monitor wont fit because the original D plug has a number of pins missing, and the socket wont accomodate a standard plug unless some of the pins are removed.

If I bought a suitable monitor cable and cut those pins, would a modern colour monitor work?

If I bridged all RGB pins and remove two of the 75 ohm resistors would a colour monitor work as a black and white monitor?
Michael Maurice is offline  
Old 19th Jul 2007, 9:18 am   #2
Nickthedentist
Dekatron
 
Nickthedentist's Avatar
 
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
Default Re: Vintage computer

Is this a green screen affair, with two rotary controls on the right hand side of the front panel?

If so, these are very easy to mend, on the whole, resembling a mono portable TV inside, although I've had one with a mains transformer that kept tripping my RCD.

Can't remember about the security screws... Could you post a pic?

Nick.
Nickthedentist is offline  
Old 19th Jul 2007, 10:23 am   #3
Michael Maurice
Moderator
 
Michael Maurice's Avatar
 
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
Default Re: Vintage computer

No Nick, Its Monocrome ie Black & White

I think the security screws may be nuts rather than screws.
Michael Maurice is offline  
Old 19th Jul 2007, 11:24 am   #4
arjoll
Dekatron
 
arjoll's Avatar
 
Join Date: May 2006
Location: Invercargill, New Zealand
Posts: 3,440
Default Re: Vintage computer

Is this an IBM PS/2? They usually had a 2 digit model number, e.g. PS/2 Model 35 etc. There were heaps of PS/2's - the model numbers escape me - at Otago when I was there, and even though Ernst & Young was a Compaq shop we plus we had one at the local office running the MS Mail link.

This 'model' number or the IBM product code (4 or 4-3) would be handy.

Re the monitor plug - if its a PS/2 then it will be VGA or possibly MCGA. I didn't think they did any mono-only ones, but could be wrong! What pins are knocked out? Pinout info is here.

EDIT: I've just re-read the original message. Is the problem with a computer or just the monitor?
arjoll is offline  
Old 19th Jul 2007, 2:16 pm   #5
Michael Maurice
Moderator
 
Michael Maurice's Avatar
 
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
Default Re: Vintage computer

Quote:
Originally Posted by arjoll View Post
Is this an IBM PS/2? They usually had a 2 digit model number, e.g. PS/2 Model 35 etc. There were heaps of PS/2's This 'model' number or the IBM product code (4 or 4-3) would be handy.

EDIT: I've just re-read the original message. Is the problem with a computer or just the monitor?

The number on the computer is 850 3002

Looking at the pins on the PLUG the following pins are there look at enclosed scan.
Attached Thumbnails
Click image for larger version

Name:	scan0001.jpg
Views:	168
Size:	64.3 KB
ID:	10982  
Michael Maurice is offline  
Old 19th Jul 2007, 5:08 pm   #6
yestertech
Nonode
 
yestertech's Avatar
 
Join Date: Dec 2002
Location: Coulsdon, Surrey, UK.
Posts: 2,109
Default Re: Vintage computer IBM System 2 850 3002

Its probably m/c type 8503. model 002.
I could be thinking of another monitor, but is this the one which has some sort of slots on the top - if so, there was a special tool to depress the latches inside and release the cover ? ( long time ago now ! ) Andy
yestertech is offline  
Old 19th Jul 2007, 5:26 pm   #7
Michael Maurice
Moderator
 
Michael Maurice's Avatar
 
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
Default Re: Vintage computer IBM System 2 850 3002

I've found a Dell monitor on for £5, picking it up tommorrow, I'll also get an monitor extention lead, cut the pins off the plug and see what happens. All that can happen is I'll lose a few quid.
Michael Maurice is offline  
Old 19th Jul 2007, 7:25 pm   #8
jay_oldstuff
Octode
 
jay_oldstuff's Avatar
 
Join Date: Jan 2005
Location: Hyde, Greater Manchester, UK.
Posts: 1,074
Default Re: Vintage computer IBM System 2 850 3002

Took a couple of these to the dump last week, they where mono vga, used to mess about with alot of this type of stuff. i also seem to remember you had to use a special took to depress two clips in the top to remove the back cover, you could do it with a long flat blade screwdriver but it was a bit fiddly. chopping the extra pins out of a standard lead should work fine.

Jay
__________________
The light at the end of the tunnel is probably the headlight of an oncoming train
jay_oldstuff is offline  
Old 19th Jul 2007, 10:15 pm   #9
arjoll
Dekatron
 
arjoll's Avatar
 
Join Date: May 2006
Location: Invercargill, New Zealand
Posts: 3,440
Default Re: Vintage computer IBM System 2 850 3002

There is product information on the 8503-002 monitor here, its a paper white VGA monitor from 1987.

Are there more pins in the socket on the computer? I would have thought that it was compatible with colour monitors as well.
arjoll is offline  
Old 19th Jul 2007, 11:25 pm   #10
Michael Maurice
Moderator
 
Michael Maurice's Avatar
 
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
Default Re: Vintage computer IBM System 2 850 3002

Quote:
Originally Posted by arjoll View Post
Are there more pins in the socket on the computer? I would have thought that it was compatible with colour monitors as well.
That is the problem, there isn't 15 holes in the socket so a standard monitor cant be plugged in.
Michael Maurice is offline  
Old 20th Jul 2007, 12:38 am   #11
liamoliver
Retired Dormant Member
 
Join Date: Mar 2007
Location: Nr. Harrow, NW London, UK.
Posts: 104
Default Re: Vintage computer IBM System 2 850 3002

Would I be right in assuming you are talking about a 9-pin D-SUB connector? I recenty aquired one of those monitors, and the owner told me that if a replacement monitor was needed, one could simply cut the pins off - as you suggest. But there are adaptors out there; one of the monitors he owned had one fitted.

I have a Compaq 386 that for some reason had only fourteen holes - I simply used a drill to make another one. Perhaps you could try that?
liamoliver is offline  
Old 20th Jul 2007, 11:24 pm   #12
Michael Maurice
Moderator
 
Michael Maurice's Avatar
 
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
Default Re: Vintage computer IBM System 2 850 3002

Quote:
Originally Posted by liamoliver View Post
Would I be right in assuming you are talking about a 9-pin D-SUB connector? I recenty aquired one of those monitors, and the owner told me that if a replacement monitor was needed, one could simply cut the pins off - as you suggest. But there are adaptors out there; one of the monitors he owned had one fitted.

I have a Compaq 386 that for some reason had only fourteen holes - I simply used a drill to make another one. Perhaps you could try that?
Thats actually not a bad idea Liam, as I have some 0.8mm drills for PCB's, I might just try that!
Michael Maurice is offline  
Old 22nd Jul 2007, 8:11 pm   #13
Michael Maurice
Moderator
 
Michael Maurice's Avatar
 
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
Default Re: Vintage computer IBM System 2 850 3002

Success! Got monitor, drilled hole in D socket, plugged monitor in and Bingo. Another happy customer.

Does anyone want a dead monochome monitor.
Michael Maurice is offline  
Old 23rd Jul 2007, 7:48 am   #14
Nickthedentist
Dekatron
 
Nickthedentist's Avatar
 
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
Default Re: Vintage computer IBM System 2 850 3002

Well done Michael... and Liam
Nickthedentist is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 6:19 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.