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TI-92 Expansion Port
The
TI-92 introduced early in 1996 featured a small
Expansion Port on the backside of its housing. With the complete address- and
data-bus of the M68000 compatible CPU available, upgrades of both the Operating
System and user memory capacity were made easy.
Texas Instruments used at the very beginning of the TI-92 market introduction OTP ROM (One-time Programmable Read-Only Memory) for the Operating System of the calculator instead the later Mask ROM soldered on the main printed circuit board (PCB). The printed circuit board (PCB) of the module contains two integrated circuits:
• OTP-ROM: 2*MX27C4000, 512kx8 bits, each |
Texas Instruments used at the very beginning of the TI-92 market introduction OTP ROM (One-time Programmable Read-Only Memory) for the Operating System of the calculator instead the later Mask ROM soldered on the main printed circuit board (PCB). The printed circuit board (PCB) of the module contains two integrated circuits:
• OTP-ROM: 2*AT27C040, 512kx8 bits, each |
The TI-92 E module was introduced early in 1996 and added the choice of 5 user languages (English, French, German, Italian and Spanish) and an additional 128k Bytes User memory. The printed circuit board (PCB) of the module contains two integrated circuits:
• ROM: IEC9895S-960819E, 1Mx8 bits • RAM: TC551001B, 128kx8 bits |
The TI-92 II module was introduced early in 1996 and added the choice of 5 user languages (English, French, German, Italian and Spanish) and an additional 128k User memory. The printed circuit board (PCB) of the module contains two main integrated circuits:
• Flash ROM: Sharp LH28F016S, 2Mx8 bits • RAM: TC551001B, 128kx8 bits |
The TI-92 Plus module was announced November 7, 1997 and arrived mid-1998 in the shelves for about $75. It boosted the TI-92 with the enhanced Flash-technology into an user-upgradable calculator. Compared with the pre-programmed Operating Systems of both the TI-92 and TI-92 II the Flash-memory of the TI-92 Plus module could be re-programmed by the user with a simple download cable connected to a personal computer. The printed circuit board (PCB) of the module contains two main integrated circuits:
• Flash ROM: Sharp LH28F016S, 2Mx8 bits • RAM: TC551001B, 128k*8 |
It took another year before the "real" TI-92
Plus calculator was introduced.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, June 8, 2003. No reprints without written permission.