19 Mar
2015
19 Mar
'15
12:02 p.m.
From: Mark Kahrs
there are very nice SRAMs available: for example, the
Cypress CY62167
is a 2Mx8 1Mx16 RAM in 48 pin TSOP. So you'd need two ...
(n.b. there is a 4Mx8 but it's only in BGA, so fuggitaboutit).
Actually, one 4Mx8 (assuming it's really only 8 bits wide) wouldn't be as
easy to work with as two 2Mx8; since most QBUS cycles are 16-bit word, not
byte, you'd have to do two memory cycles for each QBUS cycle -> more
complexity.
Noel
19 Mar
19 Mar
12:13 p.m.
On 2015-03-19 17:02, Noel Chiappa wrote:
And for the 11/70, we're talking about 32-bit wide memory...
Johnny
From: Mark
Kahrs
there are very nice SRAMs available: for example,
the Cypress CY62167
is a 2Mx8 1Mx16 RAM in 48 pin TSOP. So you'd need two ...
(n.b. there is a 4Mx8 but it's only in BGA, so fuggitaboutit).
Actually, one 4Mx8 (assuming it's really only 8 bits wide) wouldn't be as
easy to work with as two 2Mx8; since most QBUS cycles are 16-bit word, not
byte, you'd have to do two memory cycles for each QBUS cycle -> more
complexity. 
20 Mar
20 Mar
2:21 a.m.
On 2015-03-19 17:13, Johnny Billquist wrote:
On 2015-03-19 17:02, Noel Chiappa wrote:
And for the 11/70, we're talking about 32-bit wide memory...
Just because nobody mentioned it so far, what about the cy7c1460?
1mx36, so you even get the parity if you like one.
Used them quite a lot, are nice chips, and speedy too.
From:
Mark Kahrs
there are very nice SRAMs available: for example,
the Cypress
CY62167
is a 2Mx8 1Mx16 RAM in 48 pin TSOP. So you'd
need two ...
(n.b. there is a 4Mx8 but it's only in BGA, so fuggitaboutit).
Actually, one 4Mx8 (assuming it's really only 8 bits wide) wouldn't be as
easy to work with as two 2Mx8; since most QBUS cycles are 16-bit word,
not
byte, you'd have to do two memory cycles for each QBUS cycle -> more
complexity.
7:32 a.m.
On 2015-03-20 07:21, emanuel stiebler wrote:
On 2015-03-19 17:13, Johnny Billquist wrote:
Sounds like a perfect fit for the 11/70. One chip, and you're done. :-)
Johnny
On 2015-03-19 17:02, Noel Chiappa wrote:
And for the 11/70, we're talking about 32-bit wide memory...
Just because nobody mentioned it so far, what about the cy7c1460?
1mx36, so you even get the parity if you like one.
Used them quite a lot, are nice chips, and speedy too. From:
Mark Kahrs
there are very nice SRAMs available: for example,
the Cypress
CY62167
is a 2Mx8 1Mx16 RAM in 48 pin TSOP. So you'd
need two ...
(n.b. there is a 4Mx8 but it's only in BGA, so fuggitaboutit).
Actually, one 4Mx8 (assuming it's really only 8 bits wide) wouldn't
be as
easy to work with as two 2Mx8; since most QBUS cycles are 16-bit word,
not
byte, you'd have to do two memory cycles for each QBUS cycle -> more
complexity.
7:40 a.m.
On 2015-03-20 12:32, Johnny Billquist wrote:
guess,
why we used it for the ks10 ;-)
On 2015-03-20 07:21, emanuel stiebler wrote:
Just because
nobody mentioned it so far, what about the cy7c1460?
1mx36, so you even get the parity if you like one.
Used them quite a lot, are nice chips, and speedy too.
Sounds like a perfect fit for the 11/70. One chip, and you're done. :-) 
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