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 28th Apr 2021, 10:05 am   #1
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,823
Default Cosmac CDP1802

Another of my old treasures has surfaced.

This is a pretty unusual processor as its CMOS, most processors of the era were NMOS.
https://en.wikipedia.org/wiki/RCA_1802

None of the micros built up have yet re-surfaced (if indeed I kept them)

The reason CMOS was important at the time was radiation, CMOS can take lots of it NMOS not so much so pretty handy for say a battlefield tactical communications system where nukes might be employed.
It was also used in space probes due to its low power consumption and again I would guess its radiation resistance.

Not intending to do anything with this at present time just a curiosity for now

Some pics of some of the other items with it (there were at least 30 various processors + support chips and proms in the plastic drawer)
There's an 8080, Fairchild F8, 1702 Eprom, 5203 Eprom

Cheers

Mike T
Attached Thumbnails
Click image for larger version

Name:	WhatsApp Image 2021-04-28 at 09.52.14.jpg
Views:	101
Size:	33.1 KB
ID:	232826   Click image for larger version

Name:	WhatsApp Image 2021-04-28 at 09.52.56.jpg
Views:	94
Size:	35.2 KB
ID:	232827   Click image for larger version

Name:	WhatsApp Image 2021-04-28 at 09.53.18.jpg
Views:	90
Size:	37.3 KB
ID:	232828  
__________________
Invisible airwaves crackle with life or at least they used to
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is online now  
Old 28th Apr 2021, 10:23 am   #2
Keith956
Heptode
 
Keith956's Avatar
 
Join Date: Jun 2019
Location: Oxfordshire
Posts: 719
Default Re: Cosmac CDP1802

The really rad hard ones were made in Silicon-on-Sapphire (SOS) as that didn't latch up like ordinary CMOS. And they cost a small fortune.
Keith956 is offline  
Old 28th Apr 2021, 10:27 am   #3
SiriusHardware
Dekatron
 
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
Default Re: Cosmac CDP1802

Believe it or not, there are people who collect old chips like those EPROMs - not to use, but just for their aesthetic appeal / appearance, much like collecting stamps or beermats.
SiriusHardware is offline  
Old 28th Apr 2021, 10:28 am   #4
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,823
Default Re: Cosmac CDP1802

Nothing was too good for our boys their radios would still work while they fried

I first met this beastie in late 1976 the processor replaced a discrete CMOS processor using ALU's and half a dozen support IC's.

Cheers

Mike T
__________________
Invisible airwaves crackle with life or at least they used to
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is online now  
Old 28th Apr 2021, 10:30 am   #5
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,823
Default Re: Cosmac CDP1802

Quote:
Originally Posted by SiriusHardware View Post
Believe it or not, there are people who collect old chips like those EPROMs - not to use, but just for their aesthetic appeal / appearance, much like collecting stamps or beermats.
Yes us collectors are a funny old lot

As they come from my first full time job after college they are more than just collectables to me.

Cheers

Mike T
__________________
Invisible airwaves crackle with life or at least they used to
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is online now  
Old 28th Apr 2021, 12:35 pm   #6
TonyDuell
Dekatron
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
Default Re: Cosmac CDP1802

The early-ish Microwriters (text entry/storage units with a chording keyboard) used the 1802 I think. Certainly the MW4 did, I've just looked at the circuit diagram. I guess the low power consumption of the CMOS device was useful here.
TonyDuell is offline  
Old 28th Apr 2021, 3:19 pm   #7
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Cosmac CDP1802

I used the 1802 in the first piece of 'professional' microprocessor-based equipment I ever designed [for data-collection on highly bio-secure pig-breeding farms]. Its big attraction was its low power-consumption when compared to other microprocessors of the same era, meaning the whole thing could be built into a hermetically-sealed [IP67] immersion/UV-light-sterilisation/jet-wash-with-disinfectant-proof box and the [Mercury!] batteries would last for a year of typical use.
G6Tanuki is offline  
Old 28th Apr 2021, 4:09 pm   #8
NivagSwerdna
Triode
 
Join Date: Feb 2021
Location: Kingston upon Thames, Greater London, UK.
Posts: 11
Default Re: Cosmac CDP1802

That's the first microprocessor I ever programmed, via switches on a homebrew COSMAC elf built by my physics teacher!

I see your location...

I was a regular visitor to the Exeter and District Amateur Computer Club at the time... used to meet in the University Chemistry department... wow that was a long time ago!
NivagSwerdna is offline  
Old 28th Apr 2021, 5:28 pm   #9
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,823
Default Re: Cosmac CDP1802

Hi Andrew

It was a small crowd so we would have certainly met.

I had moved on to Z80's and 6502's by then

It was pretty active as I recall!

I usually attended with one or more of the Xtal Research Guys

Work commitments meant I didn't attend as often as I wanted to.

Cheers

Mike T
__________________
Invisible airwaves crackle with life or at least they used to
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is online now  
Old 28th Apr 2021, 8:48 pm   #10
ortek_service
Octode
 
ortek_service's Avatar
 
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,394
Default Re: Cosmac CDP1802

Apparently the 1802 was the only processor that was simple enough to have its circuitry 100% formally-verified for correct operation. So presumably didn't have any undocumented instructions that didn't work, and meant it was approved for space etc. applications.
However, they were very nice to program by all accounts - But maybe not much worse compared to some other oddities at the time like the F8 or even early PIC's.

IIRC, Philips also used one in an old Pager-Programmer interface, I've got.


Yes, White ceramic 'pre-production' / Industrial-spec CPU's are quite desirable. So when a friend found a 6502 in something, he swapped it for a standard plastic one and got £100 for the ceramic IC.

Not sure if, just like the old computers, the 'stock market bubble' will eventually burst in the future, and it's best to cash in before then and but them back again later. Or whether these have all been through the large first and only crash in prices already.
ortek_service is offline  
Old 28th Apr 2021, 8:49 pm   #11
circuitryboy
Pentode
 
circuitryboy's Avatar
 
Join Date: Jun 2012
Location: Bristol, UK.
Posts: 115
Default Re: Cosmac CDP1802

As well as voyaging to Jupiter in the Galileo spacecraft, the 1802 was processor of choice for early 'micromouse' builders because of the low power requirements. These 'mice' are miniature maze-solving robots competing to navigate a new labyrinth in the fastest time.
Competitions continue to this day.
circuitryboy is offline  
Old 28th Apr 2021, 9:32 pm   #12
jimmc101
Heptode
 
jimmc101's Avatar
 
Join Date: Mar 2009
Location: Portsmouth, Hampshire, UK.
Posts: 674
Default Re: Cosmac CDP1802

Another radio from Plessey Westleigh that used the 1802.

Jim
Attached Thumbnails
Click image for larger version

Name:	1.jpg
Views:	59
Size:	48.6 KB
ID:	232875  
jimmc101 is offline  
Old 28th Apr 2021, 9:52 pm   #13
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,823
Default Re: Cosmac CDP1802

Quote:
Originally Posted by jimmc101 View Post
Another radio from Plessey Westleigh that used the 1802.

Jim
Nice one Jim

Yes I am not surprised Plessey like to use Government money to develop other products

I think this one was after my time I certainly never saw any development models but it probably shares a great deal of Ptarmigans design and probably came from the same teams
I left West Leigh in 1978

Looks as if the CDP1802 had a lot of uses.

Cheers

Mike T
__________________
Invisible airwaves crackle with life or at least they used to
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is online now  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 11:48 pm.


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.