AMI (AMERICAN MEGATRENDS INC.) CHECK POINT CODES FOR PRE 4/9/90 BIOS The 286 and later AMI bios's have a check point trace in them to indicate where the code is at should a problem occur while booting. This checkpoint code is output to port 80 as a hex code and can be monitored with a special board costing about 50$ available in several magazine adds. The following is a list of the codes for pre 4/9/90 286 bios's. 01____NMI is disabled, and 286 registor test about to start 02____286 registor test is finished 03____ROM checksum OK (F000:0000--->F000:FFFF) 04____8259 initialization OK 05____CMOS pending interrupt disabled 06____Video disabled and system timer counting OK 07____channel 2 of 8253 test OK 08____channel 2 delta count test OK 09____channel 1 delta count test OK 0A____channel 0 delta count test OK 0B____parity status cleared 0C____refresh and system timer OK 0D____refresh link toggling OK 0E____refresh periods on/off 50% OK 0F____?????? 10____confirmed that refresh is on and about to start 64k memory 11____address line test OK 12____64k base memory test OK 13____interrupt vectors initialized 14____8042 keyboard controller test OK 15____CMOS read/write test is OK 16____CMOS checksum/battery check is OK 17____monochrome mode set OK 18____color mode set OK 19____start to look for optional video ROM 1A____optional video ROM control OK 1B____display memory read/write test OK 1C____display memory read/write test for alternate display is OK 1D____video retrace check is OK 1E____global equipment byte set for video OK 1F____mode set call for mono/color OK 20____video test is OK 21____video display OK 22____power on message display is OK 23---->2F ??????? 30____virtual mode memory test about to start 31____virtual mode memory test started 32____processor in virtual mode 33____memory address line test in progress 34____memory address line test in progress 35____memory below 1MB calculated 36____memory size computed OK 37____memory test in progress 38____memory initialization finished below 1MB 39____memory initialization finished above 1MB 3A____display the memory size 3B____about to start memory test below 1MB 3C____memory test below 1MB OK 3D____memory test over 1MB OK 3E____about to go to real mode (shutdown) 3F____shutdown was successful and entered real mode OK 40____attempt disable A20 address ling 41____gate A20 line disabled successfully 42____about to start DMA controller test 43---->4d ???? 4E____address line test OK 4F____processor in real mode after shutdown 50____DMA page registor test OK 51____DMA unit 1 base registor test about to start 52____DMA unit 1 channel OK, about to start channel 2 53____DMA channel 2 base registor test OK 54____about to test f/f latch for unit 1 55____f/f latch test both units OK 56____DMA unit 1 and 2 programmed OK 57____8259 initialization over 58____8259 mask registor check OK 59____master 8259 mask registor OK and about to start slave 5A____about to check timer and keyboard interrupt level 5B____timmer interrupt OK 5C____about to test keyboard interrupt 5D____ERROR! timer/keyboard interrupt not in proper level 5E____8259 interrupt controller error 5F____8259 interrupt controller test OK 60---->6F ???? 70____start of keyboard test 71____keyboard BAT test OK 72____keyboard test OK 73____keyboard global data initialization OK 74____floppy setup about to start 75____floppy setup OK 76____hard disk setup about to start 77____hard disk setup OK 78____ 79____about to initialize timer data area 7A____verify CMOS battery power 7B____CMOS battery verify OK 7C____ 7D____about to analyze diagnostic test results for memory 7E____CMOS memory size update OK 7F____about to check optional ROM C000:0 80____keyboard sensed to enable setup 81____optional ROM control OK 82____printer global data initialization OK 83____serial global data initialization OK 84____80237 check and test OK 85____about to display soft error message 86____about to give control to system ROM E000:0 87____system ROM E000:0 check over 00______controll given to INT_19 boot loader _______________________________________________________ hopefully this info helps somewhat