Topic : Chips 'n Chips Author : Michael Ruge Version : chips_x.hyp (01/05/2001) Subject : Dokumentation/Hardware Nodes : 1505 Index Size : 35662 HCP-Version : 3 Compiled on : Atari @charset : atarist @lang : @default : @help : @options : -i -s +zz -t4 @width : 75 View Ref-File After a RESET (power-up or reset button) the cpu (68000/68030) will start executing at the address pointed to by locations 4-7 which is ROM (MCU maps the first 8 bytes of ROM) at $FC0000-7 (by ROM-TOS 1.00 - 1.04) or $E00000-7 (by ROM-TOS 1.06 - 4.04). Location $000004 points to the start of the operating system code in ROM. The following sequence is then executed: 1. Perform a reset instruction (outputs a reset pulse) 2. Read the longword at cartridge address $FA0000. If the data read is a "magic number", execute from the cartridge (ROM cartridge instructions take over here). If not, continue 3. Check for a warm start (see if RAM locations were written), initialize the memory controller 4. Initialize the PSG-Chip (deselect disk drives), setup screen rate (50 or 60 Hz), write default values to the color palette and set the display pointer to 0x10000 5. Size both banks of memory 6. if not a warm start, zero memory 7. Clear the low 64K of memory and setup operating systemvariables 8. Set up exception vectors 9. Initialize the MFP-Chip (Initialize both MFP-Chips on TT030) 10. Set screen resolution (check the Monitor ID Pins) and enable interrupts by bringing the IPL to 3. 11. Attempt to boot floppy; attempt to boot harddisk, run program 12. if no boot disk, the 192/256/512K ROM TOS will bring up the desktop. Number of Bombs und Meaning Bombs Meaning 2 Bus Error 3 Adress Error 4 Illegal Instruction 5 Divide by Zero Error 6 CHK-Exception-CPU Interupt 7 TRAPV-Exception-CPU Interupt 8 Privilege Violation-CPU Interupt 9 TRACE-Exception-CPU TRACE Interupt 10 Line 1010 Emulator 11 Line 1011 Emulator 12-23 Unassigned, should have no occurence 24 Spurios interupt, Bus error during interupt processing 25-31 Autovector Interupt, Even numbered vectors are used, others should have no occurence 32-63 Trap Instruction, CPU read instruction which forced exception processing 64-79 MFP Interrupt 80-255 User Interrupt weiterblättern Kapitel Der Systemstart der Rechnerhardware, Seite 1