FW: How much memory?

[Craig Pugsley]

>   My solution to your delima is to use a chip that can be configured in single
> chip mode or expanded mode (8051 family, 6811, etc).  With something as
> complicated as this project, don't fool yourself that you will only build one. 
> If you try to limit yourself to hardware that will be the development system
> and the final product, it could be so unpleasent to work with that it will
> loose it's fun.  I have a development system that is 10 times as big as
> necessary, 10 times as much memoy, 10 times as much power supply, etc.  I have
> a 6811 in expanded mode with a 32k ram chip (I debug most of my code out of
> ram, when it works, transfer it to eprom) and 32k eprom.

That's what I was planning to do (use a 'boot' program to load code from
the serial port into ram),
The main problem I have is to figure out what the final size is likely
to be so I can make an initial processor choice. While chips in this
family (8051) share code that is very similar, they vary dramatically
with IC pinouts (IE Can't just drop in the latest & greatest device
without reconfiguring the pinout)

> computer).  No passenger seat, the dash is ripped out and a big breakout box
> (of all the computer wires) is put in it's place.  With thermocouple wires and
> sensor wires all over the place, and a computer where the passenger seat was,
> it gets quite a few stairs when I bring it in to get the emmissions checked!

;-)

Also, on my QFP socket question I received two replies:
> Also, is there such a thing as a socket for a 'quad flat pack' SMD IC.
> I can find them for PLCC packages but not QFP, and QFPs are pretty
hard
> to wire wrap :-/ Any ideas?.

        SAMTEC makes QFP to PGC Adapter boards for a variety of
        QFP Packages. Chip Specific Adapters "SPEC" for a variety
        of Motorola and Intel Chips,
        As well as Chip Generic Adaptor "GEN" for various lead count
        JEDEC and EIAJ QFPs. Simply solder down, and Plug in to a PGA
        socket!
        SAMTEC phn 800 726-8329.


Depends on what size you need. 3M makes PQFP sockets in 84, 100, 132,
164,
and 196 pin counts. I believe AMP makess a line too, but I don't have
their
catalog handy. The 3M ones use a staggered pin layout, so you really
couldn't
use them on standard perf board.

Craig
pugsley at trl.oz.au