ZX81 and TS1000 Variations
ZX81 Variations https://www.sinclairzxworld.com/viewtopic.php?f=7&t=1387&p=14693#p14693
| PCB Ver | Bottom Solder Mask Color |
| ISSUE 1 | GREEN |
| ISSUE 3 | RED ( SOME GREEN EXIST) |
| When | TYPE | DATE | Back Porch | ||
| Earlier | 2C158E type number is on the bottom |
four digit date code on the top (eg 8111 |
normally soldered directly to the board |
missing | |
| Later | 2C184E | often socketed | missing | ||
| Last | 2C210E | has |
Missing back porch causes many color TV's to show a very dark images with white parts shown as dark grey.