Datamath Calculator Museum TMC0501/TMC0501E Emulator

Date of introduction:  January 15, 2024 Display technology:  
New price:  $1,049.95 (2022 = $169.95 in 1974) Display size:  
Size:  3.2" x 1.8" x 1.1"
 82 x 46 x 28 mm3
Weight:  1.6 ounces, 45 grams Serial No:  0001
Batteries:   Date of manufacture:  mth 01 year 2024
AC-Adapter:  DC 5V (USB) Origin of manufacture:  USA
Precision:   Integrated circuits:  Arduino Nano Every
Memories:  6k Bytes SRAM, 48k Bytes Flash ROM Displays:  
Program steps:   Courtesy of:  Joerg Woerner

The TMC0501/TMC0501E Emulator is part of the modular DCM-0500 (Platform) to allow Recording of ROM Images of the Integrated Circuits (ICs) used with calculators based on the TMS0500 Building Blocks for Scientific and Programmable Calculators and connects to the West-Port of the TMS0500 ROM Platform.

The TMC0501/TMC0501E Emulator uses a software approach to stimulate the signals necessary with the various ROMs of the TMS0500 Building Blocks using an Arduino Nano Every running different programs selected with a rotary switch, level-shifters from the 5 Volt Outputs of the Arduino microcontroller to the PMOS levels used with the ROMs and a DC/DC converter to provide the voltages used with the TMS0500 Building Blocks, namely VSS (0 V), VDD (-10 V) and VGG (-15.8 V).

The user interface of the TMC0501/TMC0501E Emulator is pretty simple, the rotary switch selects one of 3 programs and a blue [PLAY] button starts the program and enables the level-shifters for the various output signals. The "Playlist" in the Arduino Nano Every software includes:

0-7: Access First ROM Bank 0 to 7 of the TMS0500 Building Blocks (1,024 13-bit Instruction Words, each)
8: Access Second ROM of the TMS0500 Building Blocks (5,000 2-digit BCD Keycodes)
9: Access Constant ROM of the TMS0500 Building Blocks (8*16 16-digit Constants)

Three green LEDs on the TMC0501/TMC0501E Emulator signal the status of its internal and external voltages and a blue LED labeled [LIVE] signals the status of the level-shifters to avoid hot-swapping of ROMs on the TMS0500 ROM Platform.

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If you have additions to the above article please email:

Joerg Woerner, January 7, 2024. No reprints without written permission.