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From: toddpw@tybalt.caltech.edu (Todd P. Whitesel)
Newsgroups: comp.sys.apple
Subject: Re: The Apple IIf
Message-ID: <1990Feb27.032627.16301@spectre.ccsf.caltech.edu>
Date: 27 Feb 90 03:26:27 GMT
References: <10892.net.apple@pro-lep>
Sender: news@spectre.ccsf.caltech.edu
Organization: California Institute of Technology
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[ somebody wrote, about EEPROMS ]

>>Yes, but they also have several points against them; namely - cost and
>>availibility.  Last time I checked, there was only one place I found that
>>had 28256's (32k x 8, I think?), and it would have cost about $600 for four
>>of them (128K) to put on my AST Ramstak+.  I _think_ they're pretty slow, too
>>200 ns or so.

200ns is fast for EPROMs and EEPROMs. If you want them faster it costs big time
and as long as you are using them as a solid state disk they really don't need
to have an awesome access time anyway. Even if they were as slow as 300 ns,
you could still run them in excess of 2 mhz which is more than fast enough for
a disk drive if you are using DMA to read it. (The 65816 block move is not too
shabby either.)

The resulting disk would be as fast as your GS ramdisk, and if DMA was used
(why doesn't anyone make a DMA based standard slot RAMdisk using slow SIMMs
or something? it's not hard and it's real cheap.) then you could get around
a Megabyte per second which is fast enough to make the system loader the
bottleneck and not the smartport driver.

Who here would buy a card that could give you a 1 megabyte RAMdisk at 1
Megabyte per second into and out of the GS?

I bet I could cook up wire wrap plans for one that would cost less than
$200 total parts cost, with the prototype board and the RAMs being the
major cost.

Todd Whitesel
toddpw @ tybalt.caltech.edu