Search found 94 matches

by Jo Even
Wed Sep 18, 2019 12:53 pm
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

hlide wrote:
Wed Sep 18, 2019 12:12 pm
Did you try with EmuZ-800?
I have not been able to get these emulators working on my Windows 10 PC. 700-emulator shows blue and black bars on the "screen", 800-emulator just a black screen.
by Jo Even
Wed Sep 18, 2019 12:31 pm
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

I'm tempted to ask my friend to probe PC7 with a logic analyzer to see what's actually happening.
by Jo Even
Wed Sep 18, 2019 12:29 pm
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

Is that so? did you test it yourself and put the rear switch in the exact position for MZ700 mode? I don't have a real 800 so no, I did not test it myself. But I'm quite sure that it was tested in 700-mode - keyboard polling (done in the program itself by reading the matrix directly via the 8255, n...
by Jo Even
Wed Sep 18, 2019 9:12 am
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

Yes, there is no VBL interrupt on the 700. I expected the 800 to work in the same way in 700 mode, but apparently not. Tested on both emulator and a real 800. Keyboard is working in both cases, which it wouldn't unless running in 700 mode with correct memory map.
by Jo Even
Mon Sep 16, 2019 1:29 pm
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

Code: Select all

while (*(unsigned char *)0xe002 & 0x80);
This is working on the 700 but always returns immediately on the 800 emulator in 700 mode.
by Jo Even
Mon Sep 16, 2019 5:49 am
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

It doesn't work on a real 800 either. Strange that keyboard is working but VBL not, when both is handled by the 8255. Oh well, I'll worry about this later :)
by Jo Even
Sat Sep 14, 2019 8:00 pm
Forum: Assembly
Topic: online Z80 assembler
Replies: 10
Views: 2736

Re: online Z80 assembler

Speaking of z88dk - do you know how to specify the stack size? I'm running out of stack.
by Jo Even
Sat Sep 14, 2019 7:57 pm
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

Well, in that case the code should wait "forever" when I wait for bit 7 to become 1? But it returns immediately regardless of which state I wait for.
by Jo Even
Sat Sep 14, 2019 9:30 am
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

Just tested this, and the problem is not the polarity. The code always returns immediately both when I wait for 0 and 1... Very strange. I'll ask Geir to test it on his real 800.
by Jo Even
Fri Sep 13, 2019 12:34 pm
Forum: Other
Topic: Detecting VBL on 800 in 700-mode
Replies: 21
Views: 95

Re: Detecting VBL on 800 in 700-mode

I guess it could be an emulator issue, but I find it strange if such an obvious bug has slipped through... I'm using this emulator: https://sourceforge.net/projects/mz800emu/ Edit: Had a (very) quick look at the emulator source, and it's possible that the polarity of the vbl signal has been reversed...