DATAMATH PICTURES

Picture 1: The TI Programmable 58 "Donor" calculator connected with 8 wires to the
TMC0541 CROM removed from its Master Library Solid State Software Module.

Picture 2: Observing the TMC0541 CROM with a Hewlett-Packard HP-54645D Mixed Signal Oscilloscope (MSO)
showing the two Clock Signals CLK1 and CLK2, Sync Signal IDLE and the two serial data signals IRG and EXT.

Picture 3: Two "Instruction Cycles" with 16 State Times, each of the TMC0501E Enhanced Arithmetic Chip.

Picture 4: Separating apart the bidirectional, half-duplex communication signal EXT between the TI-58
and the TMC0541 CROM with two diodes and using analog comparators to detect the direction of signal flow .

Picture 5: Converting the PMOS Level Signals of the TI-58 to CMOS Levels for an Arduino Nano Every
Microcomputer and adding two 16-bit Shift Registers to listen into the serial IRG and EXT Signals.

Picture 6: Adding a State Counter to synchronize Data Capture of the Shift Registers with the internal timing of
the TI-58 and adding software to decode the four TMC0501E commands to access its "Second ROM".

Picture 7: Replacing the Nano Every with a beefier Arduino DUE and adding some push buttons to
momentarily power cycle the TI-58 and debugging its power-up sequence with the MSO.

Picture 8: And here it is - the recorded sequence of the IRG Signal (left) and EXT Signal (right) while the
TI Programmable 58 is accessing Program 24 of the Master Library showing the Keycodes.

Picture 9: Understanding the necessary sequences of IRG and EXT Signals to read Keycodes of the TMC0540
Second ROM allows "emulating" them with an Arduino Nano Every and some level shifters from CMOS to PMOS .

Picture 10: Proof-of-Concept - the ROM Content of the TMC0541 Electronically Recorded
and compared with its listing in a Texas Instruments' patent application.

Picture 11: Adding a Solid State Software Module Adapter with pogo pins to Electronically Record
Second ROM Images without removing the TMC0540 CROM Chips from their packages.

Picture 12: Four weekends into the project - the first Second ROM Image requested by our TI-59 Enthusiast.

Picture 13: Do we really want to breadboard four additional 16-bit Shift Registers to look into the
Constant ROMs of the TMC0520/TMC0530 SCOM and TMC0580 DSCOM Chips? Nope!

Picture 14: Too many breadboards spoil reliability and testability. What next? Three-dimensional designs?

Picture 15: Enter DCM-0500 Platform with TMC0501 Emulator (left), TMS0500 ROM Platform (middle) with
TMC0540 SSSM Adapter and TMS0500 8-Channel Serial Data Recorder (right) mounted on top of a 128-Bit Module.

Picture 16: Python Crash Course: Disassembler for TI-58/58C/59 Key Codes and first Key Code program Listing.
More to come...