Thomas Harte
ce099a297a
Eliminates RAM writes in ROM area.
...
I no longer think that logic is correct.
2019-05-07 17:16:22 -04:00
Thomas Harte
949c848815
Broadens address decoding.
...
To no obvious change in output.
2019-05-06 22:57:29 -04:00
Thomas Harte
9bf9b9ea8c
Ensures unmapped peripherals return a consistent value.
2019-05-06 21:32:10 -04:00
Thomas Harte
a131d39451
I now believe only the 6522 is on the synchronous bus.
2019-05-06 14:10:13 -04:00
Thomas Harte
4f5a38b5c5
Adds support for the alternate video buffer.
2019-05-05 23:05:24 -04:00
Thomas Harte
cefc3af08b
Corrects RAM read decoding when the ROM overlay is enabled.
2019-05-05 22:48:40 -04:00
Thomas Harte
96facc103a
Adds an IWM shim and corrects graphics output.
...
... now that there is some.
2019-05-05 21:55:34 -04:00
Thomas Harte
407bbfb379
Pretending the Disk II is an IWM doesn't seem to achieve much.
2019-05-05 18:12:25 -04:00
Thomas Harte
a99ebda513
Takes a first shot at (inverted) Mac video output.
2019-05-04 22:27:58 -04:00
Thomas Harte
537b604fc9
It looks like writes should always go to RAM.
...
Now I see the screen buffer being filled with `0xffff`s, along with what is probably disk motor control data.
2019-05-04 17:29:30 -04:00
Thomas Harte
98bc570bf7
Adds further boilerplate around VIA and IWM decoding.
2019-05-04 17:12:26 -04:00
Thomas Harte
181b77c490
Adds decoding of IWM accesses and respect for the ROM overlay bit.
2019-05-04 16:38:01 -04:00
Thomas Harte
bc9eb82e6f
Adds in VIA access decoding, and a note to self on video.
...
The Mac now proceeds to try to talk to the IWM.
2019-05-04 14:23:37 -04:00
Thomas Harte
29fc024ecd
Starts negotiating the Macintosh memory map.
2019-05-04 12:33:27 -04:00
Thomas Harte
c1695d0910
Adds various notes to self.
2019-05-03 23:55:28 -04:00
Thomas Harte
6d6a4e79c9
Adds the absolute basics to include a 6522 in the Macintosh.
...
Not yet wired to anything.
2019-05-03 23:40:22 -04:00
Thomas Harte
68392ce6f5
Adds enough of a concept of Mac video to get a properly initialised display.
...
Completely empty at present, naturally. Also this is the very first time I've run my 68000 at live speed. From just one data point, it's not terrible. Phew!
2019-05-03 23:25:42 -04:00
Thomas Harte
6873f62ad8
Ensures that the Mac now retains its ROM properly.
2019-05-03 22:39:09 -04:00
Thomas Harte
5f385e15f6
Adds the bare bones necessary to be able to create a Macintosh from File -> New... .
2019-05-03 22:16:07 -04:00