DATAMATH CALCULATOR MUSEUM
Radio Shack 65-504
|Date of introduction:||October 2000||Display technology:||LCD|
|New price:||$19.99 (SRP October 2000)||Display size:||8|
|Size:|| 3.0" x 6.2" x
75 x 157 x 8 mm3
|Weight:||3.2 ounces, 91 grams||Serial No:|
|Batteries:||2*LR43||Date of manufacture:||mth 10 year 2000|
|AC-Adapter:||Origin of manufacture:||China|
|Program steps:||Courtesy of:||Ken H. Meine|
|Download manual:||(US: 3.5 MByte)|
Radio Shack, acquired by Tandy Corporation in 1963, entered the market of Checkbook Calculators in November with this EC-306. It features Account Manager functionality with three permanent (till you remove the batteries) Memories and started a very successful product line. We discovered as of now seven (w/o counting Tandy versions) different family members:
|• 1982: Radio Shack
EC-306 / 65-696, 3 Memories
• 1982: Tandy EC-306 / 65-696, 3 Memories
• 1987: Radio Shack EC-308 / 65-996, 3 Memories
• 1987: Radio Shack EC-430 / 65-570, 3 Memories, Taiwan
• 1988: Radio Shack EC-430 / 65-570A, 3 Memories, Thailand
• 1996: Radio Shack EC-455 / 65-569, 1 Memory, TAX
• 2000: Radio Shack 65-504, 3 Memories, TAX, violet CC keys
• 2002: Radio Shack 65-504A, 3 Memories, TAX, blue CC keys
Dismantling the featured
Radio Shack 65-504 Checkbook Calculator manufactured in October 2000 in China reveals a
clean design centered around around an unknown single-chip calculator circuit
mounted in Chip-On-Board (COB) technology directly on the printed circuit board
and hiding under a small epoxy blob. The electronics is powered by two small
LR43 batteries. Learn how to decipher the
date code on the pictured
Inspecting the PCB of this 65-504 manufactured in 2000 brought our attention to a small mark reading DB-413 REV:4, a reference to Datexx DB-413, and Revision 4 of the design (schematics and layout).
Learn more about single-chip calculator circuits used in Account Manager Calculators.
Don't miss the Corvus CheckMaster introduced by Mostek already in 1975. This rare product retains the balance of your memory even when shut off but uses power-hungry electronics.
If you have additions to the above article please email: firstname.lastname@example.org.
© Joerg Woerner, February 26, 2020. No reprints without written permission.