Re: DIY Ram Card for ][+

[mjmahon@aol.com (Michael J. Mahon)]

Michael Black wrote:

>Rich J. (aiiadict@gmail.com) writes:
>> "Robert C." <robc638killspam@sympatico.ca> wrote in message
>news:<CnuJc.25308$TB3.906987@news20.bellglobal.com>...
>>> Anyone know where I can get the schematics for a 16K (or larger) ram card
>>> for the ][+?
>> 
>> I'll send you one for $15.  complete, no soldering required.
>> 
>That has to be the most common card, followed by parallel cards, serial cards
>and Z80 cards, though I'm less certain of the order of the last three.

"Most common card" for the ][ and ][+, but, given the huge predominance
of //e's over earlier ]['s, the 16K RAM card is much scarcer than, say,
64K cards for //e's.

However there is one eBay seller who has been selling out a bunch of
"new, old stock" 16K cards over the last few months...

>It's the less than common cards that might require building.  But ironically,
>they may not be so buildable, given the parts.  I once bought a clone board
>for the Saturn 128K memory expansion board, and there was at least one IC
>on it that was hardly common at the time (though it was available), and
>twenty years later, it would be easier to design from scratch than find
>that IC.

I know exactly the one you mean--it generates the RAS and CAS timing
and refresh for the DRAMs on board.  When I built mine, I got the IC from
the same swap meet vendor that sold me the board, and was glad I did.

-michael

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