I'd already spotted those FIFO's in my search; that's why I didn't bother to include them (just remarked that they were expensive).

Yes, the FIFO idea would be perfect if they didn't cost £10 each!

Just looking at the 4256 (32k x 8, not 256k x 4?), will take me a while to wrap my head round this stuff, and the various bus types. You keep my enthusiasm though, and an 8-pin DIP would be so aesthetically satisfying!

The datasheet http://www.st.com/stonline/products/literature/ds/6757/m24256-bw.pdf
Aha! I see you referring to a different 4256. The one Farnell have discontinued of course.
says READ is independent of the WRITE control, does that mean read and write can be performed simultaneously?

EDIT: I Guess not, since it only has one data I/O
*sigh* Who'd have thought it'd be so bloody difficult just to make something act like a big shift register!

 

the FIFO idea would be perfect if they didn't cost £10 each!

The FIFOs I found cost around 95 Euros, or around £81.
As far as I'm concerned, those FIFOs can sit on the shelf in their warehouse until they crumble to dust.

Ye Olde Junque' Shoppes may be your friend. See if there are any antique computer enthusiast groups in your area; perhaps amateur radio groups (I don't know if they have such things in the U.K.).

As I think I mentioned before, you might salvage good DRAM IC's from older technology defunct video cards. Maybe I didn't, but it's still a good place to look.

Here in the States, we have a number of electronic enthusiast groups; most notably the ARRL (American Radio Relay League)
Website: http://www.arrl.org/

There are occasionally "HAM fests" and "HAMventions" (one coming up in Dayton, OH) where one can pick up on rather unique items, sometimes at bargain prices. Being a savvy shopper always pays off.

 

Don't worry, I am pretty savvy when it comes to obtaining old parts (Heck, I can buy 4164s on ebay). But the whole point of my existence is to make circuits that I publish so other people can build them (people who cant necessarily program MCUs), which demands readily available parts. So I was hoping to update that old schem, not just build a one-off. I want to create, not merely copy.

 

OK then - take a look at these.

Mouser just started carrying these:
http://www.mouser.com/ProductDetail...=sGAEpiMZZMs6Aik9Fp479mHMY/xjjrmzwY/YjFWjvIY=
http://www.onsemi.com/pub_link/Collateral/N02L63W3A-D.PDF

$3.08/ea, 2MB static RAM, organized as 128k words x 16, or 32k x 16 x 16.

 

... and 4000 series CMOS are all but obsolete.

Are they really? Sorry but I see so may designs (we are hobbyists, aren't we?) that still use them and in a proper way.

My drawers, much to my regret, are still full of both, 7400 and CD 4000

 

Are they really? Sorry but I see so may designs (we are hobbyists, aren't we?) that still use them and in a proper way.

My drawers, much to my regret, are still full of both, 7400 and CD 4000

Yeah, I have quite a selection of both of them as well - some of them are 30 or more years old. Just goes to show you how old the technology is.

If a manufacturer can replace three or more IC's with a uC, FPGA or the like, they'll do it. Board space is expensive, and assembly/troubleshooting/QC costs skyrocket with increasing parts count.

Sadly, hobbyists don't drive the market. Large manufacturers do.