On Mon, Apr 30, 2018 at 10:07 AM, Geoffrey Oltmans <oltma...@gmail.com> wrote: > On Sat, Apr 28, 2018 at 6:34 PM, Ethan Dicks via cctalk > <cctalk@classiccmp.org> wrote: >> >> Hi, All, >> >> I've been doing component-level diagnosis of a bad Amiga 1000 WCS >> board and since I was unable to find this information anywhere, I >> thought I'd post it to the list so that it's in the hands of more than >> one person. > > > I wonder if one might be able to use the excellent Diagrom in place of the > A1000 ROMs to do some testing.
When I started debugging these dead A1000s, I took a look at Diagrom... https://github.com/ChuckyGang/DiagROM/blob/master/DiagROM.s There's code in there to handle the A1000 as a separate case, but it seems only to remove features to make it fit in smaller EPROMs, and that is a recent update. The original DiagROM was written for all later machines, without a WCS board. > At least then you might be able to put some known patterns into the WCS to > read back and see if they make sense. One could use the DiagROM as a starting point and _add_ those tests in. I haven't gone over the specifics, but there is some code in the real A1000 ROMs to write enable the WCS board before reading in the Kickstart disk. The exact value to write to which address is documented somewhere but I haven't done any digging to find it. I've just been using the Fluke and running the processor for a few seconds (UUT button) to let the ROMs do their thing, _then_ using the Fluke for RAM tests at $FC0000-$FFFFFF. If I hadn't had the Fluke handy, I'd probably have taken the route of writing some new ROM code to test WCS RAM. Fortunately I also have an old Grammar Engine PromICE so I could plug that into the ROM sockets and do some quick turnover on the code development before burning real EPROMs. -ethan