wichert@quando.UUCP (Peter Wichert) (05/19/88)
Last time I tried to set up my own little small 'kernel' to see how my own vbl's and hbl's work. Therefore I have a hardware initialisation- procedure, similar to the BIOS procedure. But something unexpected happens: After the init is done, a thin bright vertical stripe at the left border of the screen appears. This stripe is much brighter than the normal white of the screen. Does anyone know about this ??? I don't. Bye, Peter
leo@philmds.UUCP (Leo de Wit) (05/26/88)
In article <428@quando.UUCP> wichert@quando.UUCP (Peter Wichert) writes: > >Last time I tried to set up my own little small 'kernel' to see >how my own vbl's and hbl's work. Therefore I have a hardware initialisation- >procedure, similar to the BIOS procedure. But something unexpected happens: >After the init is done, a thin bright vertical stripe at the left border >of the screen appears. This stripe is much brighter than the normal white >of the screen. Does anyone know about this ??? I don't. > > > Bye, Peter Humm, looks like no horizontal scans are done (I'm not quite sure how to say this in English; it seems the voltage for horizontal bending the beam is constant). Are you sure that the IPL mask in the status word is set correctly? I know that the standard HBL does something like: move.w sr,d0 and.w #$700,d0 * test the 3 IPL bits. bne.s nochange * if not zero or.w #$300,sr * could be wrong; don't know if this is valid nochange rte The ipl bits are available on pins of the MC68000; these probably are used to communicate with peripherals (interrupt control lines). It could be that your HBL is not run, or that it does not set the interrupt control lines correctly (using the status word). Maybe you could supply some more info (could be mail) ? Leo.