4 MB memory unibus/qbus card (was Qbus split I&D?)

Noel Chiappa jnc at mercury.lcs.mit.edu
Thu Mar 19 11:02:36 CDT 2015

    > 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


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