1.stack is creating with initialisation of ss:sp only. if you wish to test memory first, you may use ram-less call trick in your code:
this trick is used in bios on the first stage when memory is not used yet. look into any bios to check how does it work. you may use also far procedure call, just put value to "restore" cs also into that local "stack"
2.your cpu has no brain to differ ram from rom. it is the task of your software. just place ram into the start of adress range, and rom into the end of it. cpu will need ffff:0000 adress in rom after reset and ram starting from 0000:0000 for interrupts vectors (if they are in use in your device, of course)
look there: you may found a code there to blink through lpt on 386 board without installed memory at all: http://www.winasm.net/forum/index.php?showtopic=770
it is generally useless, but works, so, can be used as test This post has been edited by shoorick on Dec 7 2009, 07:11 AM