9 Jun
2002
9 Jun
'02
9:38 a.m.
Tony Duell wrote:
Intel also made it (or at least they made something
called a 3242 with
the same functions from what I can see).
It's basically the address path logic for 16K DRAMs (7 address lines to
the RAM). It's a 7-wide 3-input multiplexer and 7 bit counter (for the
refresh address). The 3 inputs to the mux are the high 7 address inputs,
the low 7 address inputs, and the output of the counter.
Did anybody make something for 64K DRAMS as well.
Most 6502/6800 machines used video access for refresh and the Z80
had built in refresh so only the 8080 really needed such a chip.
Back then a 4k/8k/16k static memory board was a option too rather
than DRAM board. Sigh ... Remember when 4x1K 450 ns static ram
was the best thing since sliced bread?
--
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html