DATAMATH CALCULATOR MUSEUM
Texas Instruments TI-85 ViewScreen™
|Date of introduction:||1990||Display technology:||LCD dot matrix|
|New price:||Display size:||8 * 21 characters|
|Size:|| 6.5" x 4.8" x
166 x 121 x 22 mm3
|Weight:||6.0 ounces, 170 grams||Serial No:||032198|
|Batteries:||Date of manufacture:||mth 02 year 1992|
|AC-Adapter:||Origin of manufacture:||USA (LTA)|
|Precision:||Integrated circuits:||2*Toshiba T7778A, T7900|
|Program steps:||Courtesy of:||Joerg Woerner|
The TI-85 ViewScreen panel is connected with a flat-ribbon cable permanently to a modified TI-85 graphing calculator. Placing the panel on a raised platform with an additional lens on the overhead projector enlarges the image of the handheld screen so that each student can follow along. The used platform was in the 90s commercially available from the Polaroid Corporation to project Polaroid color-graph type 691 overhead transparencies.
an early TI-81 ViewScreen manufactured end of 1990 reveals no surprises. The
reflective background surface was removed from a standard TI-81 graphic LCD
display to achieve a transmissive characteristic. The remaining circuit looks
really straightforward and consists of two Toshiba T7778A column drivers and one
T7900 row driver.
Don't miss the similiar TI-81 ViewScreen connected to the first generation TI-81 VSC. Main differences are the resolution of the LCD display and the added connector for an external AC adapter.
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© Joerg Woerner, February 23, 2009. No reprints without written permission.