128, 160, or 192 color clocks. In the widest mode, only 352 pixels (176 color clocks) are actually visible. See DMACTL. Horizontal fine scrolling moves the scrolling region up to 16 color clocks. See HSCROL. The GTIA Map modes must be horizontally scrolled in steps the size of an entire pixel (2 color clocks), instead of one color clock. See HSCROL and the discussion, Horizontal Fine Scrolling Vertical fine scrolling moves the scrolling region the number of scan lines in a single Mode line of the scrolling region, up to a maximum of 16 scan lines. See VSCROL. Although ANTIC's Display List program counter is 16-bit, only the lower 10 bits change during normal (i.e. sequential) execution of the Display List. This means the Display List requires a JMP (Jump) instruction to cross a 1K boundary. This is not a serious limitation, because the size of a single Display List usually varies from 32 to 202 bytes, and virtually never exceeds 720 bytes. Since it can be located anywhere in the memory, there is little difficulty finding a sufficiently sized place in memory that does not cross a 1K boundary. The Memory Scan Register, a register addressing the data stored in the screen memory, is 16-bit, but only the lower 12 bits change when ANTIC is sequentially scanning the video memory. This means the Display List requires a Mode line instruction including the LMS (Load Memory Scan) option where screen memory crosses a 4K boundary. ANTIC's graphic modes E and F require more than 7.5K of screen memory for a full screen display. The Display Lists for these displays require the LMS option added to a Mode instruction near the middle of the display where screen memory crosses the 4K boundary. The 4K boundary cannot be crossed within the middle of a Graphics Mode line, but only between the end of one Mode line and the beginning of the next line. In other words, the memory for the previous Mode line ends at the exact last byte of the 4K block and the next Mode line begins at the exact first byte of the next 4K block. The character set can be located anywhere in the memory (see CHBASE), but, depending on the ANTIC Text Mode, the starting address must align to a 512-byte or a 1K boundary. The Player/Missile memory map may occur anywhere in memory (see PMBASE), but,