Search CMOS RAM chips

  • Thread starter Pierre-François (f5bqp pf
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Pierre-François (f5bqp pf

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Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp
 
Pierre-François (f5bqp_pfm) wrote:
Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp
Click to expand...
These devices are long obsolete.

You can use the CMOS RAM 5101 in place of these all you have to do is
invert the chip select (as I recall). Pin-for-pin the same otherwise.
You may have to use a CMOS inverter and tie it to the battery supply for
the memory retention to work correctly - you will need to read the spec
sheets on both chips to figure that out...

At least there are still al lot of 5101s left.

--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
 
Le 28/02/2011 00:15, John Robertson a écrit :
Pierre-François (f5bqp_pfm) wrote:
Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp


These devices are long obsolete.

You can use the CMOS RAM 5101 in place of these all you have to do is
invert the chip select (as I recall). Pin-for-pin the same otherwise.
You may have to use a CMOS inverter and tie it to the battery supply for
the memory retention to work correctly - you will need to read the spec
sheets on both chips to figure that out...

At least there are still al lot of 5101s left.
Click to expand...
Hi John,

Thanks for the info, I'll look at it.

All the bests.

pf
 
"Pierre-François (f5bqp_pfm)" Inscribed thus:

Le 28/02/2011 00:15, John Robertson a ĂŠcrit :
Pierre-François (f5bqp_pfm) wrote:
Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp
Click to expand...
I might have some kicking about. Give me a chance to check.

--
Best Regards:
Baron.
 
Le 28/02/2011 20:15, Baron a ĂŠcrit :
"Pierre-François (f5bqp_pfm)" Inscribed thus:

Le 28/02/2011 00:15, John Robertson a ĂŠcrit :
Pierre-François (f5bqp_pfm) wrote:
Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp


I might have some kicking about. Give me a chance to check.
Click to expand...
Thanks Baron.

All the bests
pf
 
Michael Black wrote:
On Sun, 27 Feb 2011, "Pierre-François (f5bqp_pfm)" wrote:

Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

Any static RAM is going to be better than those, larger capacity and
faster speed. Unless this is to replace RAM in some existing equipment,
one might as well start with higher density cmos RAM, if you don't need
the extra space just set the unneeded address lines to a stable state.

Even if this is to replace RAM in existing equipment, it might be easier
to build some sort of adapter to plug in than try to find such old RAM.
In 1976 it was a great way to get some RAM with the RCA Cosmac Elf, but
even then it was a pretty small amount of RAM.

I don't know what's available these days, but there was a whole wave of
CMOS RAM that had the same basic pinouts as standard ROM. Or when this
sort of question came up even some years back, someone suggested cache
RAM off an older motherboard, it was something like 24pin package but
a narrow DIP.

Michael
Click to expand...
These are 22 pin midwide ICs. The difference between 5101s and these is
minor, one select line needs to be inverted. I assumed this is for
existing board and it would be too much trouble to make up a kludge
socket to replace the two 6561s...

Still one could fool around with a 2116LP or similar and accomplish the
same results.

John :-#)#

--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
 
Le 01/03/2011 03:57, Michael Black a écrit :
On Sun, 27 Feb 2011, "Pierre-François (f5bqp_pfm)" wrote:

Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

Any static RAM is going to be better than those, larger capacity and
faster speed. Unless this is to replace RAM in some existing equipment,
one might as well start with higher density cmos RAM, if you don't need
the extra space just set the unneeded address lines to a stable state.

Even if this is to replace RAM in existing equipment, it might be easier
to build some sort of adapter to plug in than try to find such old RAM.
In 1976 it was a great way to get some RAM with the RCA Cosmac Elf, but
even then it was a pretty small amount of RAM.

I don't know what's available these days, but there was a whole wave of
CMOS RAM that had the same basic pinouts as standard ROM. Or when this
sort of question came up even some years back, someone suggested cache
RAM off an older motherboard, it was something like 24pin package but
a narrow DIP.

Michael
Click to expand...
Hi Michael,

Thanks for your reply and your ideas, I've looked at that but the space
between the boards is so small that I cannot use the piggyback technique.

pf
 
Le 01/03/2011 06:58, John Robertson a écrit :
Michael Black wrote:
On Sun, 27 Feb 2011, "Pierre-François (f5bqp_pfm)" wrote:

Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

Any static RAM is going to be better than those, larger capacity and
faster speed. Unless this is to replace RAM in some existing equipment,
one might as well start with higher density cmos RAM, if you don't
need the extra space just set the unneeded address lines to a stable
state.

Even if this is to replace RAM in existing equipment, it might be
easier to build some sort of adapter to plug in than try to find such
old RAM.
In 1976 it was a great way to get some RAM with the RCA Cosmac Elf, but
even then it was a pretty small amount of RAM.

I don't know what's available these days, but there was a whole wave of
CMOS RAM that had the same basic pinouts as standard ROM. Or when this
sort of question came up even some years back, someone suggested cache
RAM off an older motherboard, it was something like 24pin package but
a narrow DIP.

Michael

These are 22 pin midwide ICs. The difference between 5101s and these is
minor, one select line needs to be inverted. I assumed this is for
existing board and it would be too much trouble to make up a kludge
socket to replace the two 6561s...

Still one could fool around with a 2116LP or similar and accomplish the
same results.

John :-#)#
Click to expand...
Hi John,

As I replied to Michael, the space between the boards is so small that
building a piggyback module is impossible.
However I guess I've found these ICs, I'm waiting for two of these.
I'll need to find one or two others as spare just in case...

pf
 
On Sun, 27 Feb 2011 21:17:02 +0100 "Pierre-François (f5bqp_pfm)"
<pfmonet@wanadoo.fr> wrote in Message id:
<4d6ab13e$0$32451$ba4acef3@reader.news.orange.fr>:

Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp
Click to expand...
How about Ebay:
http://shop.ebay.com/i.html?_nkw=256x4+SRAM&_sacat=0&_odkw=256x4&_osacat=0&_trksid=p3286.c0.m270.l1313
 
Le 01/03/2011 11:12, JW a écrit :
On Sun, 27 Feb 2011 21:17:02 +0100 "Pierre-François (f5bqp_pfm)"
pfmonet@wanadoo.fr> wrote in Message id:
4d6ab13e$0$32451$ba4acef3@reader.news.orange.fr>:

Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or better)
reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp

How about Ebay:
http://shop.ebay.com/i.html?_nkw=256x4+SRAM&_sacat=0&_odkw=256x4&_osacat=0&_trksid=p3286.c0.m270.l1313
Click to expand...
Yes thanks, I got two of these, they where not here yesterday.

pf
 
"Pierre-François (f5bqp_pfm)" Inscribed thus:

Le 28/02/2011 20:15, Baron a ĂŠcrit :
"Pierre-François (f5bqp_pfm)" Inscribed thus:

Le 28/02/2011 00:15, John Robertson a ĂŠcrit :
Pierre-François (f5bqp_pfm) wrote:
Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or
better) reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp


I might have some kicking about. Give me a chance to check.


Thanks Baron.

All the bests
pf
Click to expand...
The ones I have are HM6564 ! Sorry. :-(
If I come across any I'll let you know.

--
Best Regards:
Baron.
 
Le 02/03/2011 20:50, Baron a ĂŠcrit :
"Pierre-François (f5bqp_pfm)" Inscribed thus:

Le 28/02/2011 20:15, Baron a ĂŠcrit :
"Pierre-François (f5bqp_pfm)" Inscribed thus:

Le 28/02/2011 00:15, John Robertson a ĂŠcrit :
Pierre-François (f5bqp_pfm) wrote:
Dear Friends,

I'm trying to get 2 CMOS static RAM chips 256 x 4 (300ns or
better) reference HM6561 from Intersil or another vendor.
Could you help me to get these?

MAny thanks for your help.
All the bests.
Pierre-Francois
f5bqp


I might have some kicking about. Give me a chance to check.


Thanks Baron.

All the bests
pf

The ones I have are HM6564 ! Sorry. :-(
If I come across any I'll let you know.
Click to expand...
Thanks for your reply Baron.

All the bests
pf
 
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