Sysop: | Amessyroom |
---|---|
Location: | Fayetteville, NC |
Users: | 26 |
Nodes: | 6 (0 / 6) |
Uptime: | 61:51:40 |
Calls: | 633 |
Calls today: | 1 |
Files: | 1,188 |
D/L today: |
32 files (20,076K bytes) |
Messages: | 181,453 |
I gather that the B&W output of the ZX81 cut a lot of corners with the timing of the signal and this meant that some TVs couldn't display ZX81 output. I think it was because there wasn't a half-line vertical spacing between the odd and even fields. This reference
<http://www.fruitcake.plus.com/Sinclair/ZX81/Chroma/ChromaInterface_PictureImprovement.htm>
doesn't mention that but does mention the lack of a back porch for
clamping of the black level - a naive omission ;-)