DATAMATH

DATAMATH CALCULATOR MUSEUM

Datamath Calculator Museum DCM-50A Playground QIL42 Adapter

Date of introduction:	September 25, 2024	Display technology:	n.a.
New price:		Display size:	n.a.
Size:	2.2" x 1.1" x 0.45" 56 x 27/28 x 11 mm³
Weight:	0.3 ounces, 8 grams	Serial No:	0001
Batteries:	n.a.	Date of manufacture:	mth 11 year 2024\5
AC-Adapter:	n.a.	Origin of manufacture:	USA
Precision:		Integrated circuits:
Memories:
Program steps:		Courtesy of:	Joerg Woerner

When Sharp introduced in October 1969 with the QT-8D the World's first small electronic desktop calculator, it was using a Chipset of five LSI (Large Scale Integration) Integrated Circuits jointly developed with North American Rockwell’s Autonetics division. Four of the five chips were packaged in 42-pin Quad In-line Packages (QIP) with their prominent staggered footprint. Rockwell stayed this at first glance unusual package committed for most, if not all, of its later calculator chips.

On our mission to Characterize and Reverse-Engineer not only calculator chips manufactured by Texas Instruments, but branching out to offerings from their competitors in the 1970s, namely AMI, Cal-Tex, Commodore/MOS Technology, Electronic Arrays, General Instrument, Hitachi, Litronix, Matsushita, Mitsubishi, Mostek, National Semiconductor, NEC, Omron, RFT, Rockwell, Sharp, Toshiba, and Western Digital, we encountered some challenges and created with the DCM-50A (PLAYGROUND) a modular approach to tackle these challenges and designed four different printed circuit boards (PCBs) that can be stacked on top of the DCM-50A Platform:

• DCM-50A (PLAYGROUND) FRAME: Plug-In Carrier to access all voltages and signals of the DCM-50A Platform
• DCM-50A (PLAYGROUND) LED DD FRAME: Plug-In Carrier to access all voltages and signals of the DCM-50A Platform for Chips with LED Direct-Drive capability
• DCM-50A (PLAYGROUND) DIL42: Daughter Board with 42-pin ZIF Socket, Patch Field, Diode Matrices, Push Buttons, SPDT Switches and Pin-Modifiers
• DCM-50A (PLAYGROUND) BB400: Daughter Board with Solderless Breadboard (400 connections), Push Buttons and SPDT Switches

To further increase the flexibility of the DCM-50A Platform, we designed these Playground QIL42 Adapters, converting the 42-pin Quad In-line Packages (QIPs) to a footprint compatible with both the 42-pin ZIF Socket of the DCM-50A (PLAYGROUND) DIL42 and the Solderless Breadboard of the DCM-50A (PLAYGROUND) BB400. The printed circuit boards (PCBs) come in two versions, the QIL42 for 0.9" wide 42-pin QIPs and the QIL42W for 0.95" wide 42-pin QIPs.

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