Perry Casein wrote:

Hi Paul,

Very interested in the EFI display as it would fit will into my plans with
my Glastar project.

I've got some hardware hanging around here left over from an old TMS320-C25
project of mine that that I would be glad to donate.

Goodies I have hanging round you might find useful

5 - 84 Pin PLCC Sockets
3 - 68 Pin PLCC Sockets
2 - 28 Zif Sockets
many dozen 27XXX eproms
25 - TC55328P-35 32x8 SRAM 35nS (not sure if this is fast enough for you)
lots of 74LAS-XXXN  (04, 32's, 74's, 541's, 573's...)
DIP sockets & switches etc.....

I'm certainly no expert but I'd reconsider the centronic's port loader.
Why not just use 1 PCB for prototyping as well as the real thing.  On the
PCB wire in a EPROM that would hold a ZIF on the prototype and be empty for
the production PCB.  In the PIC start-up code it always looks to see if the
prom is exists and executes from there if it does and if not it runs it's
internal firmware. I found the 60 seconds to burn a prom a nice time to grab
a coke and say a prayer to the firmware gods.

Perry Casson

All donations accepted Perry. Thanks. We can slow the development system to use those
SRAMS. The display system is not time critical anyway. If you update the display
faster 
than 1/2 a second, people just see a blur. Most GPS's update only once a second.

Those 64 pin PLCC zif sockets are over $100. You need a minimum of two. One on  the
programmer
and one on the proto board. It takes time to burn an EPROM. Then you have to pull it
from the programmer and insert it in the proto board. You need at least two PIC EPROM
chips.
One being erased and one being tested. It takes time to erase them so one would 
probably need three or four EPROM PIC's at around $20 each. I did it this way
for years and years on 6502 systems until I wised up to using static RAM in 
place of EPROMS. I program by trial and error. Mostly error :-)

I still have not bought a PIC 17C756 EPROM programmer. Tracy has one already 
so I will let him burn the code after I get done developing it in the Static RAM 
based development system.

I use the printer port because the PIC BASIC compiler runs in a PC. After the code
is compiled and stored on the HD in binary form I write a little QB BASIC utility to
poke it out the printer port at high speed and store it in the development system
RAM. 

Course this does not work in Windows so I run the whole thing in good old 
DOS. Windows 
does not allow direct hardware access to the ports.

I also use a couple of other computers to simulate Tracy's EFI and the GPS. The
software
for these is again written in compiled basic and  the data is sent out the serial 
ports in real time.

If an when Tracy decides to go with a complete EFIS with a large LCD display we can
use
the same hardware to develop that.

Paul Lamar
 
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