Search found 60 matches

by Maziac
Wed Oct 24, 2018 3:34 pm
Forum: Software
Topic: Copper
Replies: 5
Views: 1431

Re: Copper

Many thanks for the comprehensive answer. What is the supposed way to read the current raster line? There are 2 bytes for high and low byte at register 30 and 31. I.e. it has to be read one byte at a time. If the raster line changes just in between the 2 byte accesses the result would be completely ...
by Maziac
Tue Oct 23, 2018 5:18 pm
Forum: Software
Topic: Copper
Replies: 5
Views: 1431

Copper

Hi all, I have a few questions regarding the Copper implementation. Writing the index to the "Copper control bytes": is this the index at which the program should start or is it the index for the next write to the "Copper data" register? If I write more than 2k data (1k instructions) to the "Copper ...
by Maziac
Fri Sep 14, 2018 10:26 am
Forum: Software
Topic: SETAE
Replies: 6
Views: 1119

Re: SETAE

Yes, I'm using it in a completely different context.
It is still usable. I just work the other way round now.
by Maziac
Thu Sep 13, 2018 7:53 pm
Forum: Software
Topic: SETAE
Replies: 6
Views: 1119

Re: SETAE

Thansk for the info, I hadn't expected that.
by Maziac
Thu Sep 13, 2018 4:56 pm
Forum: Software
Topic: SETAE
Replies: 6
Views: 1119

SETAE

Hello,
the specification is a little vague about this instruction:
will it just set the bit and leave the other bits alone or will it zero out A before setting the bit.

E.g. What is the result of this:
LD A,10000000b
LD E,2
SETAE

Will it be
A=00000100b
or
A=10000100b
?
by Maziac
Sun Sep 09, 2018 11:01 am
Forum: Software
Topic: Sprite mirroring, rotation
Replies: 0
Views: 1658

Sprite mirroring, rotation

Hi,

The 'Sprite Attribute Upload' has 3 bits for x, y- mirroring and rotation.
What is the order in which those are executed?
Is it mirrored first then rotated?
Or first rotated and then mirrored?
by Maziac
Fri Sep 07, 2018 4:30 pm
Forum: Software
Topic: PIXELAD/PIXELDN
Replies: 4
Views: 857

PIXELAD/PIXELDN

Hi,
a question about these 2 new instructions:
What will happen if the y-coordinate is bigger than 191?
I.e. what result is stored in HL if I use
LD E,0
LD D,192
PIXELAD

Similar question for PIXELDN:
What will be the result if HL is already in the last (y=191) line?
by Maziac
Wed Sep 05, 2018 7:37 pm
Forum: Software
Topic: Sprite palette offset
Replies: 9
Views: 8330

Re: Sprite palette offset

@Cesar: Just tested your last commit: works excellent with your fix now.
by Maziac
Wed Sep 05, 2018 7:01 pm
Forum: Software
Topic: Sprite palette offset
Replies: 9
Views: 8330

Re: Sprite palette offset

Thanks.
by Maziac
Wed Sep 05, 2018 4:05 pm
Forum: Software
Topic: Memory bank switching improvement
Replies: 1
Views: 472

Memory bank switching improvement

I was wondering if there exist ideas to improve the memory switching in the future. Currently the bank switching switches all accesses at the same time, i.e. READ, WRITE and OPCODE fetch. It would beneficial to have an independent memory bank switching for any of those accesses. I.e. it can simplify...