Home made memory expansion.

Feek · 03-02-2011, 22:47

I went to my mums today and picked up an old computer of mine.

In it is a home built memory expansion card. It's a thing of beauty.

The front is just four chips in sockets, the back is where it all happens.

Take a look at this.

I built that. From scratch. I had a circuit diagram for it and just built from the circuit, if I remember correctly the three memory bugs are effectively paralleled up with some switching lines going up via a controller to the BUS connector.

Total capacity - 24Kb RAM.

Here it is fitted in the computer.

Even back then I was overclocking. There's a switch hanging out of the back which doubles the clock speed from 1MHz to 2MHz!

Those were the days, huh? Can you imagine building a memory expansion card for a computer nowadays.

Will · 03-02-2011, 23:11

*like*

Mondo · 04-02-2011, 01:39

Whoa, i never knew you can do that kind of things DIY!

Feek · 04-02-2011, 09:47

Quote:

Originally Posted by Mondo

Whoa, i never knew you can do that kind of things DIY!

I doubt you can now - That was back in the very early 1980s.

Mark · 04-02-2011, 11:36

No way you could do this now (most computer PCBs are multi-layer due to the sheer number of tracks required), but I do remember when things were much simpler and you could do this sort of thing.

Never built one myself but I know of others who did. It's now that far from the time you could get an entire computer in kit form. Imagine doing that now!

Sadly my knowledge doesn't extend to recognising the computer involved, but credit for doing it nonetheless.

kaiowas · 04-02-2011, 13:15

Back in the day when "Building your own computer" meant something!

I like the "Side two" printing on the board too, really dates it back to the age of vinyl.

Jonny69 · 08-02-2011, 13:36

Quote:

Originally Posted by kaiowas

Back in the day when "Building your own computer" meant something!

I like the "Side two" printing on the board too, really dates it back to the age of vinyl.

Amen to that. Only the other day I was talking to some friends about how the days of being able to start certain businesses are over. One example was creating an empire based on a computer built out of bits from Tandy

Feek · 08-02-2011, 13:53

http://cgi.ebay.co.uk/Acorn-Atom-ful...#ht_6911wt_922

No bids yet but plenty of watchers.

I'm going to try and slap a PSU up it this evening and see if I can show it working.

Feek · 05-02-2011, 00:37

It's actually an Acorn Atom from around 1980 and it's going on eBay on Sunday.

Nutcase · 05-02-2011, 10:01

Do I get points for recognising an Acorn product?

When we were using the Beebs all the time we bought all sorts of kits you assemble to upgrade them. Don't think we ever made anything from scratch though!

03-02-2011, 22:47	#1
Feek ex SAS Join Date: Jun 2006 Location: JO01ou Posts: 10,062	Home made memory expansion. I went to my mums today and picked up an old computer of mine. In it is a home built memory expansion card. It's a thing of beauty. The front is just four chips in sockets, the back is where it all happens. Take a look at this. I built that. From scratch. I had a circuit diagram for it and just built from the circuit, if I remember correctly the three memory bugs are effectively paralleled up with some switching lines going up via a controller to the BUS connector. Total capacity - 24Kb RAM. Here it is fitted in the computer. Even back then I was overclocking. There's a switch hanging out of the back which doubles the clock speed from 1MHz to 2MHz! Those were the days, huh? Can you imagine building a memory expansion card for a computer nowadays. __________________ Last edited by Feek; 03-02-2011 at 22:54.

03-02-2011, 23:11	#2
Will BBx woz 'ere :P Join Date: Jan 1970 Posts: 2,147,487,208	like __________________ *No No!*

04-02-2011, 01:39	#3
Mondo Absinthe Join Date: Jul 2006 Posts: 2,174	Whoa, i never knew you can do that kind of things DIY! __________________ My Website / MSN / Email / Flickr / Blog

04-02-2011, 13:15	#6
kaiowas The Stig Join Date: Jul 2006 Location: Fightertown USA Posts: 1,458	Back in the day when "Building your own computer" meant something! I like the "Side two" printing on the board too, really dates it back to the age of vinyl. __________________ Anal Fish Porn

08-02-2011, 13:53	#8
Feek ex SAS Join Date: Jun 2006 Location: JO01ou Posts: 10,062	http://cgi.ebay.co.uk/Acorn-Atom-ful...#ht_6911wt_922 No bids yet but plenty of watchers. I'm going to try and slap a PSU up it this evening and see if I can show it working. __________________

04-02-2011, 11:36	#5
Mark Screaming Orgasm Join Date: Jul 2006 Location: Newbury Posts: 15,194	No way you could do this now (most computer PCBs are multi-layer due to the sheer number of tracks required), but I do remember when things were much simpler and you could do this sort of thing. Never built one myself but I know of others who did. It's now that far from the time you could get an entire computer in kit form. Imagine doing that now! Sadly my knowledge doesn't extend to recognising the computer involved, but credit for doing it nonetheless.

05-02-2011, 00:37	#9
Feek ex SAS Join Date: Jun 2006 Location: JO01ou Posts: 10,062	It's actually an Acorn Atom from around 1980 and it's going on eBay on Sunday. __________________

05-02-2011, 10:01	#10
Nutcase Moonshine Join Date: Dec 2006 Location: Chelmsford, innit! Posts: 3,979	Do I get points for recognising an Acorn product? When we were using the Beebs all the time we bought all sorts of kits you assemble to upgrade them. Don't think we ever made anything from scratch though!