Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!apple!well!dsmall
From: dsmall@well.sf.ca.us (David Small)
Newsgroups: comp.sys.atari.st
Subject: Re: TT questions
Message-ID: <22798@well.sf.ca.us>
Date: 22 Jan 91 00:20:01 GMT
References: <14770@milton.u.washington.edu>
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
Lines: 51


The thread asks TT questions.

The TT can have up to 4 megabytes of "ST RAM". This is RAM that has
video contention; e.g., the processor can't get to it whenever it would like
to,
because the video chips are tied up displaying the picture. It's a lot like
ST RAM and runs programs in it, and so forth.

	The TT can also have fastRAM, or "TT RAM". It's on a daughterboard
which I recently learned is an option you need to ask for; it's not standard.
Anyway, that has either 4 megs or 16 megs of RAM on it, depending on which
size SIMM you choose, 1 meg or 4 meg. All this RAM (ST/TT) is SIMM mounted and
dynamic RAM; I am not aware of any static RAM in the system.

	For completeness' sake, there is a chip with around 60 bytes of
battery-backed up RAM in there somewhere; I know almost nothing about it.

	TT RAM is burst mode (if you buy the right sorta SIMMS), 32-bit,
very quick RAM that is not slowed down by video. (My benchmarks show a 2-3X
improvement -- video takes a BIG chunk out of the TT's ST-RAM bandwidth).
Programs loaded into TTRAM, by setting the program-flag to do so, really
scream
along much faster; the flag lets you selectively load programs into the RAM
they
will work in, as some programs will break in TT-RAM. (TT-RAM cannot display
video or
do ACSI disk I/O directly to it, although buffering through ST-RAM is easy 
enough.)

	The TT is apparently shipping with 720K drives. According to another
network, Atari tested out prototypes of a new chip that was supposed to run\
at the higher density, but it was flaky, so they went to 720K. Also
according to elsewhere, there is a jumper if they ever get it working to
supply the new chip the higher clock rate. I would be very surprised if the
DreamPark board to do highest density drives wouldn't work in TT, though.

	I read that TT currently has only FCC Class A that we all know from 
Stacy, so you may have trouble getting one *at all* unless you are
a non-residential application. I am not going to suggest you tell the dealer
that you work downtown in an industrial area and are going to put your TT
next to your arc welder, all in a fully metal-shielded Faraday cage room.

	My guess would be you will have a tough time getting a "custom" TT.
The configurations I saw with dealer pricing all had hard disks, for
instance. 

	Good luck, and I hope the information helps. Feel free to ask if
I can tell you anything more that'll help.

	-- thanks, Dave Small / Gadgets