Smith-Corona Marchant 10095-F  
Written by Accutron on 2017-03-17  

The Smith-Corona Marchant 10095-F is a memory PCA from an as-yet unidentified model of large desktop calculator. The 10095-F features a TDK EM-2985 432-bit magnetic core memory plane, capable of storing the equivalent of 108 BCD digits. While this is a small fraction of the core memory typically used in computers from the era, it's a substantial amount for an early electronic calculator. For comparison, the impressive NCR 18 desktop calculator has only 256 bits of core memory. The remainder of the card is occupied by sense amplifier hardware, primarily built from uncharacterized CDC10107C and CDC10157F transistors.

Special thanks to Victor Rizzardi for donating this rare memory device.

SCM 10095-F magnetic core memory PCA.

10095-F, enlargement of TDK EM-2985 core plane.

EM-2985 core plane under magnification.

This article is part of the [Logic & Memory Circuits] exhibit.

©2000-2019 The Vintage Technology Association. All rights reserved.