[Oberon] What boot LEDs mean, point me to some docs

Michael Schierl schierlm at gmx.de
Sat Oct 24 22:55:50 CEST 2020

Hello Jörg,

D7+D2 is 84H, not 82H.
(D0=1H, D1=2H, D2=4H, D3=8H, D4=10H, D5=20H, D6=40H, D7=80H)

If reading from RAM or writing to RAM were totally broken, it would not
get that far.

One possible reason (just a guess) would be if RAM reading as data
works, but reading as code would not. Since at that point a RAM
instruction is executed for the first time (before it was all in ROM).

But as for most memory problems, it could be many other things as well.



Am 24.10.2020 um 16:49 schrieb Jörg:
> As it’s stuck on 82H it could be that the boot loader could not not load the oberon core from CF to memory.
> If the boot loader finished loading the oberon core, but the core hangs, leds would stick on 80H.
> If something is wrong with the memory, the behaviour is difficult to predict. When I added SDRAM and did something wrong in the beginning, the inner core created „strange“ C2H sometimes C4H traps.
> Br, Jörg
>> Am 24.10.2020 um 16:22 schrieb Michael Schierl <schierlm at gmx.de>:
>> Hello,
>>> Am 24.10.2020 um 15:50 schrieb D EMARD:
>>> HI
>>> A collegue is rying to make cleaner rework of SDRAM and cache for
>>> oberon at ulx3s board
>>> https://gitlab.com/pnru/ulx3s-misc/-/blob/master/oberonstation/ob_video.tgz
>>> Old code which works has this boot LED sequence (or bits):
>>> D7+D1, D7+D2, D5 ... then video, mouse and kbd work
>>> New code under development boots
>>> D7+D1, D7+2 and stays there

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