Mapped Devices

• Description

Haven't you never dreamed (....hummm) of 3Mbytes of more memory on your calc ?
Or maybe you prefer the memory + a real time clock ?
Or, maybe again, you have your own idea of what device to mapped... a floppy disk or a thermal sensor ?
Ah, ah, ah here you'll find all the informations needed to do that :)

• Documentation

   For the moment, not to much. Don't forget to check out: Marvin and Jean-Jacques MICHEL's page.

• Pictures and Schematics

Shematics and explanations are coming soon !!!

Download the PSpice compatible schematic of the Bus Expander. The pcb is 32mm x 40mm... Convert into inch if necessary !!

 

Check out how to expand the capabilities of your TI92 !

To use the Bus Expander, you'll need to solder (only) 2 wires on the TI92 mainboard. We have found that on our TI92 mainboard the following pins aren't used by the calc. Well, actually you have to connect those pins in yellow below to correspondant CPU pins (!):

• Upper left pins to pin 16 of the CPU, CS4 (Chip Select at $C00000)
• Upper right pins to pin 18 of the CPU (CE1 RAM in 8 bits access mode)

Be CareFULL! That's NOT an easy part. And of course, neither DBA nor Texas Instruments, could be responsibles in ANY way for what you are doing. You also need a very precise solder iron. PLEASE GIVE UP if you can't handle it...

 

 

CS4 Pin 16

CE1/ RAM

D3

D2

D1

D0

GND

A1

A3

A5

A7

A18

CE1/ RAM in 8bits access Pin18

VCC  RAM

RW/

D11

D10

D9

D8

GND

CE/  ROM

A2

A4

A6

A8

A19

TI92 Bus       Connectors are 2x13 pins (2mm spacing between pins).

VCC  RAM

?

VCC  ROM

D12

D13

D14

D15

VCC  ROM

A16

A14

A12

A10

A20

?

CE2  RAM

D4

D5

D6

D7

GND

A17

A15

A13

A11

A9

?

 

 

 

• History