A92: New design-Please Read


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A92: New design-Please Read



Due to Motorola discontinuing the microproccessor that I was originally going
to use and someones suggestion to use a PIC microcontroller.  I looked around
on Microchips web page and found a reasonable good match that runs a lot
faster(33 MHz).
Because of this I, once again, redesigned the entire project.  What I am
going to have is everything designed in a slightly complex modular system.
 This will allow for future expansion.  I am going to have a seperate
interface unit that deciphers the TI-protocal, figuring out which type of
file is being sent, what kind of calculator is sending, and will also have an
added variabletype that would allow for direct control of the interface by
allowing seperate control of the datalines.
I am almost done designing a printer adapter that will automatically print a
text file when sent to the interface when it is connected, I am also planning
on allowing for more than one device to be attached at one time because only
certain ones would respond to certain file type.
Another possibility is for the interface to detect what devices are attached,
unfortunatly this would mean that I would have to change the port from a DB25
to a DB50.  
Planned pinout of DB25F connector on interface:
1 /strobe
2 D0
3 D1
4 D2
5 D3
6 D4
7 D5
8 D6
9 D7
10 send/request (for a memory expander)
11 text
12 program
13 function
14 string
15 data
16 expressin
17 figure
18 matrix
19 picture
20 list
21 macro
22 fargo control
23 system ready/reset
24 +5V
25  ground


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