Question about RAM chip history

In what year did the 8k x 8, fully static, unclocked CMOS RAM in the JEDEC 28-pin DIP first become available for purchase? A current example of this part is the Alliance Memory AS6C6264. I’ve tried searching, but perhaps I haven’t hit on the right terms.

Well I see 2003 mentioned on the last page; it looks like you can get in touch with them here:

Before 1986, at least… because in the summer of 1986 I built a 24kB RAM expansion for Vic-20, using three of these chips; Hitachi or Toshiba, I think.

In the January 1984 issue of Byte Magazine, JDR Microelectronics advertised the HM6262, 150ns, at $49.95.

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The earliest reference I could find for the HM6264 is in the first issue of Acorn User in July/August 1982:

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Odd… I’m just looking at PCW for July 1982, and I cannot see any mention of the 6264… but the 6116 was available for about £5.50.

It’s a blast looking at those old magazines… computers were much more interesting back then! (Apart from any practical concerns :slight_smile: )

Practical Electronics, March 1984, ad from Watford Electronics:

Screenshot 2023-03-21 at 13.45.55

Sorry about that - I re-checked and I made a mistake because had a later issue tagged against the wrong year. .

There is a definitely a reference in Byte magazine volume 8 issue 11 (November 1983):

I do remember using these as soon as they came out, although I’m having trouble with the exact year. I later used the 32Kx8 ones (62256 and 43256) in my 6809 second processor for the Beeb and my “Acorn User” ram/rom board for the beeb. The 32K ones were a year or two behind the 8K ones. I believe they were also used internally in the battery-backed units from Greenwich Instruments (the earlier models - tall, with yellow labels, and a big pin sticking out for the R/W’ line). So if you can find the earliest sale of those, subtract a year.

Thanks! What a great group!

It’s easy to get years and transistor counts for CPUs - Wikipedia has a page with a list. But memories are much denser than CPUs (smaller chip size for an equivalent number of transistors), and it’s tough to get similar numbers for RAMs online.

Using 6 transistor static cells, an 8k x 8 (64k bit) static RAM needs 393,216 transistors for the memory array. So call it a 400k transistor part. Given that a memory array on a die is dense, perhaps the very first 8k x 8 parts used 1500nm (1.5u) technology, which happened around 1981. The die would have been large, but maybe tolerable as a stake for market share.

400k transistors in a RAM seems definitely doable in 1-micron. Wikipedia says this didn’t happen until '84, but a lot of their information is poorly sourced (and memory parts are often used as the initial vehicle for new processes). Anyway, something like that.

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Even if the chip is out, it still took a year or two to get into the hands of the average Joe.
Also n K x 1 chips are harder to find as well. Ben.