25 Jan
2008
25 Jan
'08
3:11 p.m.
I need a programmable device, with the standard 24 pin layout, with 100nS acces time.
2716's are 350ns to 450ns, 2816's are 150nS match.
What other options do I have ?
( Target : replace some bipolar microcode proms So I can experiment a bit)
Jos
25 Jan
25 Jan
3:37 p.m.
On Fri, Jan 25, 2008 at 09:11:26PM +0100, Jos Dreesen / Marian Capel wrote:
I need a programmable device, with the standard 24 pin
layout, with 100nS
acces time.
2716's are 350ns to 450ns, 2816's are 150nS match.
What other options do I have ?
( Target : replace some bipolar microcode proms So I can experiment a bit)
You could make a socket adapter from 28 or 32 pins to 24, then use a more
modern, 100ns part, and only program the first 2K.
-ethan
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Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html
3:46 p.m.
Jos Dreesen / Marian Capel wrote:
I need a programmable device, with the standard 24 pin
layout, with
100nS acces time.
2716's are 350ns to 450ns, 2816's are 150nS match.
What other options do I have ?
( Target : replace some bipolar microcode proms So I can experiment a bit)
You just can't replace bipolar proms. :(
Jos
6:46 p.m.
woodelf wrote:
Jos Dreesen / Marian Capel wrote:
Look around for Cypress CY7C264 parts in the wide 24p package (they
come in both 600mil wide and 300mil skinny DIPs). They offer access
times down to 45-55ns and are 8Kx8 devices. Pins 18-21 are a little
different versus the 2716 (since it requires more address lines) but
all the other pins are identical. Most likely in can just drop in your
circuit as is (you just need to program multiple instances of your
2716 code into the device to alias the unused upper address lines).
These are UV eraseable devices so they can be easily reprogrammed.
Don
AK6DN
I need a programmable device, with the standard
24 pin layout, with
100nS acces time.
2716's are 350ns to 450ns, 2816's are 150nS match.
What other options do I have ?
( Target : replace some bipolar microcode proms So I can experiment a
bit)
You just can't replace bipolar proms. :(
Jos
3:53 p.m.
Date: Fri, 25 Jan 2008 21:11:26 +0100
From: jos.mar at bluewin.ch
To:
Subject: 2716 with 100 nS access time ?
I need a programmable device, with the standard 24 pin layout, with 100nS acces time.
2716's are 350ns to 450ns, 2816's are 150nS match.
What other options do I have ?
( Target : replace some bipolar microcode proms So I can experiment a bit)
Jos
Can't you replace the EPROM with a fast access RAM with a small battery?
I seem to remember that 2kbyte RAM chips, pin compatible were available
in the 100 ns range. Not sure 6116's were that fast, but perhaps the larger
types 8 kbytes were that fast. I know, they have 4 more pins, but that
can be solved with a small kludged socket.
With 2 pull-up resistors and 2 DIPswitches you can put 4 experiments in
one 8 kbyte chip :-) BTW, weren't 27256's and 27512's in the 100 ns range?
- Henk.
4:10 p.m.
Jos Dreesen / Marian Capel wrote:
I need a programmable device, with the standard 24 pin
layout, with 100nS acce
s time.
2716's are 350ns to 450ns, 2816's are 150nS match.
What other options do I have ?
sram.
i'd make a daughter board with sram and a pic, like the prom-ice...
( Target : replace some bipolar microcode proms So I
can experiment a bit)
heck, if you pick a big enough part you could just use a fpga with ram
inside like a spartan 3. (depending on how much memory and how wide)
-brad
6000
days inactive
6000
days old
5 comments
6 participants
participants (6)
-
ak6dn＠mindspring.com -
bfranchuk＠jetnet.ab.ca -
brad＠heeltoe.com -
ethan.dicks＠usap.gov -
henk.gooijen＠hotmail.com -
jos.mar＠bluewin.ch