Not exactly; this overstates the complexity of the chessboard display. The order isn't exactly what you wrote, it's bits 4567 / 76543210 / 01234567 for the thr

Not exactly; this overstates the complexity of the chessboard display. The order isn't exactly what you wrote, it's bits 4567 / 76543210 / 01234567 for the three playfield registers for the left half of the screen. This can be either repeated or mirrored for the right half. A common trick as 2600 Video Chess did was to simply not use the leftmost (mirrored to rightmost) register, which still gets you 16x2 bits of mirrored playfield in the middle, trading computational cost for a slightly smaller play area. Now an 8x8 checkered board is not symmetrical for mirroring. 2600 Video Chess actually draws only 7 of the files with the mirrored playfield registers, with the center one of the 7 (the 'e' file) straddling the mirror line. The additional (leftmost) file is actually a sprite object (the "ball"). Pretty clever. The real trick in 2600 Video Chess is drawing 8 sprites per row on a system whose hardware only has 6. It does this with the "venetian blinds" trick, where each sprite is striped onto alternating scanlines. That way there's only ever 4 actual sprites at a time, which are moved back and forth by a square's-width on alternating lines.