Amiga 3000/3000T Jumper Settings Amiga 3000/3000T Jumper Settings Jumper Pins -01 -02 -03 -04 Function ---------------------------------------------------------------------------- J100 4 2-3 2-3 1-2 1-2 Quadrature Clock Phasing J101 3 2-3 2-3 2-3 2-3 FPU Clock Source J102 3 2-3 2-3 2-3 2-3 System Clock Source J103 4 3-4 3-4 3-4 3-4 FPU CS/BERR J104 3 1-2 1-2 1-2 1-2 CPU Clock Source J151 3 2-3 2-3 1-2 1-2 ROM Timing J152 3 2-3 2-3 1-2 1-2 ROM Timing J180 3 2-3 2-3 2-3 2-3 A2000 ROM Compatibility Jumpers J181 3 2-3 2-3 2-3 2-3 A2000 ROM Compatibility Jumpers J200 3 1-2 2-3 1-2 2-3 NTSC/PAL Select J350 3 1-2 1-2 1-2 1-2 Tick Clock Source J351 3 2-3 2-3 2-3 2-3 Disable DF1: (1-2 to enable) J352 3 2-3 2-3 2-3 2-3 Light Pen Source J481 3 2-3 2-3 2-3 2-3 VDE Scan Double Only Jumper J482 3 1-2 1-2 1-2 1-2 VDE PLL Loop Adjust J483 3 - - - - VDE Factory Test Points J800 3 1-2 1-2 1-2 1-2 WD33C93 J851 3 1-2 1-2 2-3 2-3 RAM Controller Speed Jumper J852 5 4-5 4-5 4-5 4-5 -012A Ramsey only (See Notes) J853 3 2-3 2-3 2-3 2-3 -012A Ramsey only (See Notes) Notes: J150, J151: ROM Timing. The ROM timing circuit provides four different speed settings to match the output enable and access timing of the system ROMs. To set the jumpers, determine the output enable time and access times for the ROMs you wish to use. The ROM must have lower values than for the setting you select. System standard ROMs have T(oe) = 110ns and T(acc) = 250ns. CLK J151 J150 T(oe)(min.) T(acc)(min.) 16 MHz 2-3 2-3 157ns 250ns 16 MHz 2-3 1-2 220ns 312ns 16 MHz 1-2 2-3 282ns 375ns 16 MHz 1-2 1-2 345ns 437ns 25 MHz 2-3 2-3 90ns 160ns 25 MHz 2-3 1-2 130ns 200ns 25 MHz 1-2 2-3 170ns 240ns 25 MHz 1-2 1-2 210ns 280ns J180, J181: ROM Compatibility Jumpers J180 J181 A2000/A500 ROMS: 1-2 1-2 A3000 ROMs: 2-3 2-3 J851-J853: RAM Controller Compatibility Settings J852 J853 -012A Ramsey w/ 256K4 RAMs 4-5 2-3 Later Ramseys w/ 256K4 RAMs 2-3 1-2 Later Ramseys w/ 1M4 RAMs 1-2 1-2 BACK TO MAIN TECHNICAL PAGE TO CATALOG BACK TO NATIONAL AMIGA