Quote:
Originally Posted by SpeedGeek
Been There Done That! You don't need faster PAL's or GAL's. Everyone has overlooked the clock speed limitations of your A3000 or A4000 motherboard. The solution is to run your motherboard with a synchronized 20 Mhz clock but you will need a few cut an jumper modifications and a 74F74 to divide the clock on a A4000. The following results are from my A3640 @40Mhz + 68030 state machine modifications + ramsey 4 clock cycle @20Mhz. AIBBLogFile *********************************************************************************** System Static Data ----------------------------------------------------------------------------- System CPU: 68040 System FPU: 68040 System MMU: 68040 CPU Clock Rate: 40.0 MHz FPU Clock Rate: 40.0 MHz Operating System Version: 40.68 ( 3.x ) ======================= System Memory Information ============================ NODE #1 Node Name: expansion memory Node Size: 16.00 MBytes Bus Port Size: 32 Bit Address Range: $07000000--$08000000 Node Priority: 30 ----------------------------------------------------------------------------- NODE #2 Node Name: chip memory Node Size: 2.00 MBytes Bus Port Size: 32 Bit Address Range: $00001000--$00200000 Node Priority: -10 ----------------------------------------------------------------------------- ***************************************************************************** ========================== Test Information Section ========================== Test Name: InstTest Parameters: Not applicable to this test. Multitasking: DISABLED Test Code Location: Memory Node #1 Test Data Location: Memory Node #1 Test Result: 7810894.89 Instructions/Second (Higher = Better Performance) ============================ Comparison Ratings ============================= This Machine : 16.94 A600-NF : 1.00 (68000 | SC Math) Base System A1200-NF : 1.75 (68020 | SC Math) A3000-25 : 5.47 (68020 | CP Math) A4000-40 : 10.05 (68020 | 40 Math) --------------- System Dynamic Information for this test ------------------- Instruction Cache: ENABLED Data Cache: ENABLED Inst Cache Burst Mode: -------- Data Cache Burst Mode: -------- Data Cache Write Allocate: -------- 68040 Copyback Mode: ENABLED ----------------------------------------------------------------------------- System Supervisor Stack Address: $07000AC0 AIBB Process Stack Address: $07218C0C Operating System Memory Location: $07FFBD00 Current OS Dispatch Quantum: 4 ***************************************************************************** END OF LOG FILE
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I have tried standard mod yesterday and able to achieve 33MHz for a minute and then yellow screen
. Can you show us the way please ? A small diagram ?
Where from is this synchronised 20MHz ?