Re: TI-H: Upgrade Ti-92 RAM

Subject: Re: TI-H: Upgrade Ti-92 RAM
From: Joe Paul Schneider <joschnei@sendit.sendit.nodak.edu>
Date: Mon, 18 Nov 1996 08:49:57 -0600 (CST)
In-Reply-To: <199611180014.SAA12974@mail.execpc.com>

Just curious, how would you go about doin' one of those... a Rom hack I
mean...




On Sun, 17 Nov 1996, Dave Collins wrote:


> I think you might have to do a ROM Hack For This... 
> 
> ----------
> > From: Bill Stysiack <wjs12@cornell.edu>
> > To: ti-hardware@lists.ticalc.org
> > Subject: Re: TI-H: Upgrade Ti-92 RAM
> > Date: Sunday, November 17, 1996 2:29 PM
> > 
> > I just ordered 2 samples from Marshall, the TC551001BTRI-85L and the
> > TC551001BTRL-70L.  I hope they send them, they are pickey about those
> > things.  Does anybody know if the 92's rom supports the extra 128k, or if
> > you would only be able to use it with a custom assembly program written
> in
> > Fargo?  
> > 
> > Bill Stysiack
> > wjs12@cornell.edu
> > 
> > 
> > At 02:49 PM 11/16/96 -0500, you wrote:
> > >  Ram.txt, which comes with Fargo, says,"The TI-92 is capable of
> addressing
> > >256 kb of interleaved RAM."  I then remembered seeing something on the
> web
> > >about an open memory socket in the TI-92, so I did some investigation.  
> > >  I first found the page with the RAM info,
> > >http://www.wam.umd.edu/~ltduck/ti92/ti92.html
> > >  I then opened my 92 and found the ram module ( labeled U10
> > >TC551001BFTL-85L.  Went to Toshiba's page and found out the pin
> assignments
> > >in a PDF file.  It is a 32 pin 128kx8 85ns 5V SRAM.  Following the paths
> on
> > >the circuit board, I figured out that the open pads on the 92's board (
> > >labeled U10R ) have the pinout of the chips TC551001BTRL-85L or
> > >TC551001BTRI-85L.  I also found that Marshall electronics sells these
> chips
> > >for about $24.
> > >  I'll try to get a free sample of the chip, Marshall gives out samples
> I
> > >think, and see what I can do.  The solder pads are VERRY close together,
> and
> > >I have a tight budget so I'm a little reluctant about messing around
> with my
> > >$150 calc.  If anyone else has more info I'd like to know. 
> > >
> > >Bill Stysiack
> > >wjs12@cornell.edu
> > >
> > >
>

References:

Re: TI-H: Upgrade Ti-92 RAM

From: Dave Collins <Lindoran@execpc.com>