DATAMATH

DATAMATH CALCULATOR MUSEUM

Datamath Calculator Museum DCM-50A Playground Digilent I/O Extender

Date of introduction:	April 21, 2025	Display technology:	n.a.
New price:		Display size:	n.a.
Size:	1.3" x 2.6" x 0.45" 34 x 65 x 12 mm³
Weight:	0.6 ounces, 17 grams	Serial No:	0001
Batteries:	n.a.	Date of manufacture:	mth 04 year 2025
AC-Adapter:	n.a.	Origin of manufacture:	USA
Precision:		Integrated circuits:	SN74AHC8541
Memories:
Program steps:		Courtesy of:	Joerg Woerner

The Datamath Calculator Museum DCM-50A Platform support Levels-shifters (3.3V – 5.0V compatible) for all signals of the Device-under-Test and various support signals:

• Inputs: Clock, Test (Init), KN/KP/KO/KQ (K8/K4/K2/K1)
• Outputs: Clock, D1-D11 (R0-R10), SA-SH, SDP (O0-O7), PHI-1 to PHI-4

All signals are made available on two connectors matching the pinout of the Digilent Digital Discovery™, a combined logic analyzer, protocol analyzer, and pattern generator instrument but can be used with any external instrument compatible with 3.3V or 5V signals. Here at the Datamath Calculator Museum we use these two connectors for both Characterization and Reverse-engineering of single-chip calculator circuits.

When using the DCM-50A (PLAYGROUND) configuration, the DCM-50A Playground Frame Carrier allow access to most of these signals:

• Digits Outputs D1 (rightmost) to Digit Outputs D11 (leftmost)
• Segments Outputs SA to SH and SDP
• Keyboard Inputs KN, KO, KP and KQ
• Digital Discovery DIN0, DIN21 and DIN22 Signals
• Digital Discovery DIO24 and DIO25

To allow probing of even more signals of the Device-under-Test, we developed this DCM-50A (PLAYGROUND) Digilent I/O Expander offering another set of six Input Signals for the Digilent Discovery:

• Digital Discovery DIN26, DIN27, DIN28, DIN29, DIN30 and DIN21 Signals

Please notice that the DCM-50A Playground Digilent I/O Expander needs to be plugged into the 12-pin connector J6 of the DCM-50A Platform.

If you have additions to the above article please email: joerg@datamath.org.