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That's very odd. Why did they invent a new CRT format and spend the cost of the hardware to implement it instead of using an off the shelf TV?
by IIAOPSW 7y ago
That's very odd. Why did they invent a new CRT format and spend the cost of the hardware to implement it instead of using an off the shelf TV?
- tyingq 7y agoBecause TVs didn't have high quality video inputs. Old Apples, C64s, etc, came with a "tiny tv broadcaster" (RF modulator) that broadcast the signal on channel 3. In shit NTSC or PAL quality, which is lower resolution than what the CRT can display.
- IIAOPSW 7y agoI understood that. I'm old enough to remember VCR's / game consoles required you to turn to channel 3 or 4. But what were the older, non-personal terminals using? Was there some sort of RF modulated raster pattern optimized for displaying text? Were they drawing everything as vectors? Did they use off the shelf CRT's?
- tyingq 7y agoDirect manipulation of the beam with analog voltage to a CRT driver for the x and y axis. Same as what the TV does inside.
- PixyMisa 7y agoThey just took a regular B/W CRT and wired it up directly - leaving out all the PAL/NTSC decode circuitry. That allowed for a much sharper picture.