White Screen / Green screen

[Computer Collector]

My TRS-80 model 4 has white letters on a black background. I know that other TRS-80s had green letters. Which one is more rare? Why did Tandy release 2 different screen types? Are the model numbers different?

-just curious

[Terry Yager]

The green screen is supposed to be easier on the eyes, but they cost more. IIRC, Trash-80s all came with white phosphors, but after-market green (& amber) CRTs were available.

--T

[vic user]

i got this from Ira's trs80 site:

Non-Gate Array Model IV
(Catalog 26-1069)
Black and White picture tube, non-clustered arrow keys, non-integrated RS232 and disk controllers. The RS-232 port faces the bottom of the unit.

Gate Array Model IV
Catalog 26-1069A
Green picture tube, clustered arrow keys, integrated RS-232 and disk controllers. The RS-232 port faces the back of the unit.


chris

[Computer Collector]

hmmm....

I wonder what "gate array" means.

[Terry Yager]

A whole buncha gates, usually on a single "field programmable" chip.

It means they used a single chip to replace a number of discrete components that were used in the earlier models.

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2005-03,GGLD:en&q=define%3Afpga

--T

[Rick Ethridge]

I have a rare non-gate array green screen Model 4 equipped with double-sided 5.25 inch external drives.

[billdeg]

European TRS 80's were less likely to be green/black.