Name: N 80 Z Type: 80 column card (videx compatible) Short description: For Apple ][+ only. Goes usually into slot 3. Switching to graphics (or 40 column text) is done via softswitch. Installation: The N 80 Z fits into any slot (except 0 and 7). Slot 3 is recommended for Pascal and CP/M. It has a 14 pin IC-socket, which needs to be plugged between IC F 14 (74LS259) on the main board and its socket: Remove IC F 14, located left near the color trim poti, plug N 80 Z socket into the motherboard socket and then put IC F 14 back on the top into the N 80 Z socket. The male BNC connector goes into the Apple's video out connector and the female BNC connector goes to the monitor. Jumper settings: No jumpers. Phew... Usage: Simply type PR#3. The screen should switch automatically to 80 column display. Key sequences: Ctrl-Z 0 Clear screen Ctrl-Z 1 Return to 40 column mode Ctrl-Z 3 Alternate charset Ctrl-Z followed by Ctrl-@ to G Lores graphic characters Ctrl-Z followed by Ctrl-P to Ctrl-Shift-O Line graphic characters Ctrl-Z followed by Ctrl-H to Ctrl-O Abbrev. for control character Ctrl-A Toggle caps lock Ctrl-G Bell Ctrl-H Backspace Ctrl-J Line feed Ctrl-K Clear to end of page Ctrl-L Clear screen Ctrl-M Carriage return Ctrl-S Stop/Start Ctrl-U Cursor forward Ctrl-Y Home (without clear) ESC followed by A to F Like on the Apple screen Ctrl-Shft-M Clear to end of line Ctrl-Shft-N followed by two characters X and Y Set cursor to X Y; the characters are calculated as X+31 and Y+31 Register settings of CRT-controller: register r/w normal value Name 00: w 7B Horiz. total 01: w 50 Horiz. displayed 02: w 62 Horiz. sync pos 03: w 29 Horiz. sync width 04: w 1B Vert. total 05: w 08 Vert. adjust 06: w 18 Vert. displayed 07: w 19 Vert. sync pos 08: w 00 Interlaced 09: w 08 Max. scan line 10: w C0 Cursor upper 11: w 08 Cursor lower 12: w 00 Startpos Hi 13: w 00 Startpos Lo 14: r/w 00 Cursor Hi 15: r/w 00 Cursor Lo 16: r 00 Lightpen Hi 17: r 00 Lightpen Lo Register is read (Slot 3 assumed): LDA #$ STA $C0B0 LDA $C0B1 Register is written: LDA #$ STA $C0B0 LDA #$ STA $C0B1 The card has 2kB rom, 4kB character rom and 2kB video ram. The rom is mapped into $CN00-$CNXFF (N is slotno) and $C800-$CBFF, the video ram is mapped (in four banks) at $CC00-$CDFF. Bank switching is done via accessing the addresses (slot 3 assumed) $C0B0, $C0B4, $C0B8 and $C0BC. Memory locations used: $06F8: Screen start address (divided by 16) $07F8: Status: Bit 0: normal/alternate charset Bit 4: 18 or 24 lines Bit 6: caps lock flag Bit 7: GET/GETLN flag $C058: Switch off card $C059: Switch on card