Characterization of Sharp Single-chip Calculator Circuits - LI2000 Product Family

The DCM-50A Platform supports the Characterization of many Non-TI single-chip calculator circuits with up to 42-pin packages using the DCM-50A Playground DIL42 Adapter mounted on top of the DCM-50A PG Frame Carrier with the voltages V_SS and V_DD/V_GG set to the appropriate levels.

LI2002

Device-under-Test:

Keyboard: The Lloyd's Accumatic 30 makes use of a keyboard assembly with 19 spring-supported plastic keys pushing small fingers on three stamped sheet-metal plates against contacts etched on a single-sided phenolic PCB. All switches but the [C] key are arranged in a 9*2 matrix with the rows connected to the D1-D9 Outputs (Display Scan) and the columns connected to the KN and KF Inputs (Keyboard Scan) of the LI2002 single-chip calculator circuit. The [C] key is connected directly between V_GG and the /ATC Input of the LI2002.

Keyboard Matrix of the Lloyd's Accumatic 30 (Model EH-9036, Type 255):

Display: The Lloyd's Accumatic 30 makes use of an 8-digit Futaba 8-CT-01A low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 8 Digit Outputs D2 to D9 and 8 Segment Outputs SA to SG and SDP of the LI2002 and biased to approximately -32 Volts. An additional discrete red LED is used as minus sign for negative numbers and connected between a transistor activated with Digit Output D1 and Segment Output G.

Display Layout:

Display Fonts:

Error Condition: The LI2002 signals error conditions like accumulator overflow/underflow or division by zero with an "8-Digit friendly" zero with all decimal points lit '. . . . . . .0. .' instead the more common 'C' or 'E'.

Scanning: Display and keyboard scanning is performed in D1 → D9 direction at a rate of about 2,200 Hz: