22 May
2009
22 May
'09
5:56 a.m.
Chuck Guzis wrote:
On 22 May 2009 at 0:23, Dave McGuire wrote:
Got a bunch of the Inmos chips, if you're interested.
I'm sure you know that you can get modern DRAM in x72, x36 and x18
configurations quite readily.
I suspect if I dig hard I can find 9 bit wide static ram of some kind,
but with the low cost of 32KBx8 ram I can waste 7 out of 8 bits.
I dont' need a tiny PCB so I have room to use for that. My front panel
needs a bit of work so it is not too wide, so hopefully both PCB's can
be about 11"x8".
On May 22, 2009, at 12:17 AM, bfranchuk at
jetnet.ab.ca wrote:
Grumbles
at the lack of 9 bit wide ram chips ... No matter how
you look at it any kind of 18 bit computer has power compared to a
16 bit or less cpu. PS. Now you know what kind of computer I am
designing, but this is off topic since only 1 off does not count as
a classic computer unless it tubes or flip/chips[1] used.
What sort of density
are you looking for? I've seen some really
nice 16Kx1 SRAM chips made by Inmos. Or you could implement a DRAM
controller in your FPGA and do it that way, with 1-bit-wide DRAM
chips. Heh, I remember needing a very fast SRAM for a
bankswitching memory
controller back in the 70's. I used a Fairchild 64x9 bipolar SRAM,
grumbling that what I really needed was a x8. The bugger drank about
a watt. I think they were available in 256x9 also. At that time,
the speeds were considered to be very fast (60 nsec), but would be
laughable now.
While memory from the 70's time frame is not missed unless you need
spares, what surprized me is all the odd custom chips that came out
about that time for bit slice and fancy control logic. Custom mask programed
roms too, but most of what I noticed from that era is surplus calculator stuff.
Ben.
--Chuck