Search found 2578 matches

by ijor
Sun Sep 16, 2018 3:26 pm
Forum: Hardware
Topic: The SECRET VIDEO MODE in an ST: 400 lines in COLOR (and with 72 Hz)!
Replies: 81
Views: 9627

Re: The SECRET VIDEO MODE in an ST: 400 lines in COLOR (and with 72 Hz)!

Yeah, sorry, exactly :) I calculated how far into the screen that black area would be and it was substantial. I would need to check the GLUE/MMU combo schematics to see what happens if you use a resolution with value = 3. On GLUE ST it wouldn't help, it considers this the same as 2 (mono). Btw, and...
by ijor
Sun Sep 16, 2018 2:55 pm
Forum: Hardware
Topic: The SECRET VIDEO MODE in an ST: 400 lines in COLOR (and with 72 Hz)!
Replies: 81
Views: 9627

Re: The SECRET VIDEO MODE in an ST: 400 lines in COLOR (and with 72 Hz)!

No time yet, but I think you're right in that a switch to avoid mono hsync will be needed. You probably mean to avoid a COLOR (not mono) hsync. Not sure how good it would work. You probably might be able to avoid the COLOR hsync, but you will have a couple of problems. You would still run a few cyc...
by ijor
Sun Sep 16, 2018 1:59 pm
Forum: Hardware
Topic: The SECRET VIDEO MODE in an ST: 400 lines in COLOR (and with 72 Hz)!
Replies: 81
Views: 9627

Re: The SECRET VIDEO MODE in an ST: 400 lines in COLOR (and with 72 Hz)!

Re: avoid BLANK being asserted on the STE

troed wrote:Well running GLUE in color during active display should work, right? Still only two changes per scanline.


Did you have a chance to test it? Is it messing with SYNC?
by ijor
Sat Sep 15, 2018 9:20 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

(joska tested Closure v1.1 and it was the same. That said, my code could still be crappy ;) ... I believe Leonard also has his own floppy DMA code. He has, but why you assume his floppy code is as crappy as yours? LOL, just kidding. Seems the problem is something else anyway. And I have a feeling i...
by ijor
Sat Sep 15, 2018 7:25 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

Edit: We Were @ - another recent trackloader - does not load with an HC installed either. It does run from harddrive (IDE), but it apparently does some crazy stuff because my LCD TV does not like it at all :D For reference: I (only) tested the harddrive version of "We were @" on the HC CP...
by ijor
Sat Sep 15, 2018 1:56 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

I must admit I never saw multicolor bombs. That must be troed and his magic demos! :)
by ijor
Sat Sep 15, 2018 1:08 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

Yes, it was the CPU socket, and yes, it has been fixed :) If you can run more tests and may show a video or some pics, it could be interesting. But so far, and after czietz test, it doesn't seem like an incompatibility of the CMOS CPU. It is possible that the disk and/or the drive is not 100%. It m...
by ijor
Sat Sep 15, 2018 1:01 pm
Forum: Applications
Topic: The Link & The Link 2 (ICD) - v6.5.5.
Replies: 3
Views: 154

Re: The Link & The Link 2 (ICD) - v6.5.5.

Thanks for the pics.

I have a Link 2, but the case is not transparent. Strange because ICD ads mention the transparent case as one of the differences in comparison to the older Link I. Anybody else have seen one like that?
by ijor
Thu Sep 13, 2018 12:57 am
Forum: Hardware
Topic: 520STE weird floppy disk drive problem
Replies: 25
Views: 4388

Re: 520STE weird floppy disk drive problem

Finally the DMA chip arrived and I had time to perform the replacement. I removed the old DMA chip, soldered a 40 pin socket and placed the new DMA chip, which is a C025913-38 PH23-030 like the previous one. Actions performed: - Re-tested the floppy cable pin by pin. All continuity measurements are...
by ijor
Tue Sep 04, 2018 8:29 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

joska wrote:https://atari.joska.no/MOV_0323.mp4
I had to powercycle to get it to display it correctly.


That sounds like a SHIFTER wakeup issue.
by ijor
Tue Sep 04, 2018 8:26 pm
Forum: 680x0
Topic: movea.b movea.w why these exist?
Replies: 23
Views: 964

Re: movea.b movea.w why these exist?

You'd be surprised how many respected experts are not aware of this. The author of vasm (yes, the assembler!) is another fine example. He had to run it on real Amiga to believe me. ;-) He didn't believe the original official Motorola manual? It is not an undocumented feature. Btw, it is not exact t...
by ijor
Tue Sep 04, 2018 4:29 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

@ijor Closure is syncing to HBL interrupt. What do you think - E-clock differences? I do analyze the E-clock jitter dynamically instead of relying on the fact that's it always the same on ST/STE [with the non-HC CPU] Don't know. But doesn't seems likely, I wouldn't expect the E clock to be any diff...
by ijor
Tue Sep 04, 2018 12:42 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

joska wrote:This demo fails on my STE with a HC CPU, but works fine with the original CPU.


How exactly it fails? It doesn't load? Corrupted screen?

Yeah, interesting.
by ijor
Tue Sep 04, 2018 12:35 pm
Forum: 680x0
Topic: movea.b movea.w why these exist?
Replies: 23
Views: 964

Re: movea.b movea.w why these exist?

So this MOVE / MOVEA dance was only to help the poor programmer to realise that OK, now I'm changing CCR and now I'm not? Yes, I think so. It's a matter of point of view. For the coder it is a different instruction with different behaviour. The coder doesn't care too much how it is exactly encoded....
by ijor
Mon Sep 03, 2018 9:53 pm
Forum: 680x0
Topic: movea.b movea.w why these exist?
Replies: 23
Views: 964

Re: movea.b movea.w why these exist?

You always use movea if you have an address register as destination as there is no move xxx, Ax instruction. Most assemblers silently convert move xx,Ax to movea xx, Ax. The same is true for add -> adda, ... From the point of view of the assembler, it is actually the other way around. Assemblers co...
by ijor
Wed Aug 29, 2018 3:13 pm
Forum: Hardware
Topic: Insert disk....
Replies: 5
Views: 277

Re: Insert disk....

It actually might be the drive that TOS is failing to detect media change. If nothing at all happens when you change the disk (the drive's led doesn't even turn on), then it can't be the disk, at least not the second one.
by ijor
Sat Aug 25, 2018 3:34 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

Also for the record: my STE has the supposedly "bad" DMA IC and an NMOS CPU as well and still works fine with ACSI devices such as the Gigafile. This shows that even that combination is not guaranteed to fail as ijor already mentioned. (I really had hoped it would, because then I could ha...
by ijor
Mon Aug 20, 2018 6:42 pm
Forum: Hardware
Topic: Reverse engineering of some ICD Link adapter
Replies: 175
Views: 18130

Re: Reverse engineering of some ICD Link adapter

Sorry to interject into this thread, but I've always wanted to hook up my scsi cd-rom drive in parallel with my ultrasatan using the Link. Is it possible or is the consensus that it would be unreliable even with a splitter? I'm not 100% sure and I am answering because nobody else did ... Chaining m...
by ijor
Wed Aug 15, 2018 1:26 am
Forum: Coding
Topic: SHIFTER reimplementation on FPGA
Replies: 78
Views: 7491

Re: SHIFTER reimplementation on FPGA

... the 16MHz clock is buffered at the socket with an MC74VHC1GT125. I wonder if this is really needed. Did you happen to test without it? I'm not suggesting to not use a level shifter and it certainly improves the noise margin, but just curious because TTL compatible output levels probably work.
by ijor
Tue Aug 14, 2018 7:34 pm
Forum: Coding
Topic: SHIFTER reimplementation on FPGA
Replies: 78
Views: 7491

Re: SHIFTER reimplementation on FPGA

So to make a stand-alone shifter with the Altera parts I can access in this old version of Quartus, I guess it would basically need all the same hardware as the HDMI board: 16 pins of bidirectional level shifters, 9 pins of downward level shifters and 10 upward level shifter for the clock and RGB (...
by ijor
Tue Aug 14, 2018 7:30 pm
Forum: Coding
Topic: Different SHIFTER versions
Replies: 65
Views: 4491

Re: Different SHIFTER versions

tin wrote:Here's the previous IMP set in 8ns and with dl3, dl6 and two different lowrez "shiftedleft" cases added.


Thanks once more again. But seems to me again that some of the traces might have the wrong resolution.

This looks like low rez, and not med rez: C070713-002IMP_med_50hz_dl3.vcd
by ijor
Mon Aug 13, 2018 1:09 pm
Forum: Coding
Topic: Different SHIFTER versions
Replies: 65
Views: 4491

Re: Different SHIFTER versions

tin wrote:Regarding „banded“ and „shifted“ ...


I suspected something like that. But the trace bandwidth (50 MHz) is a bit too low and then it's difficult to analyze unless you know beforehand what you are looking for.
by ijor
Mon Aug 13, 2018 4:13 am
Forum: Coding
Topic: Different SHIFTER versions
Replies: 65
Views: 4491

Re: Different SHIFTER versions

Hi,

The 3 "normal" low rez traces are now ok. So it sounds indeed that there was some kind of mix up with the previous one on low rez.

I didn't check the other two, banded and shifted. Not sure what you mean by this effect?

Thanks once more again :)
by ijor
Fri Aug 10, 2018 1:46 pm
Forum: HxC Floppy Emulator
Topic: HxC External floppy cable, works as A and B
Replies: 40
Views: 17307

Re: HxC External floppy cable, works as A and B

But I think that is likely to be easier/safer than either desoldering the whole AY8912 or trying snip some pins and connect wires to each end you snipped? :wink: Of course. Something like that is needed when the straps are not present at all. It is also needed on pre STE computers when you want an ...
by ijor
Fri Aug 10, 2018 1:05 pm
Forum: Hardware
Topic: STe - Bad DMA Chip
Replies: 160
Views: 26433

Re: STe - Bad DMA Chip

I don't want to rock the boat, but what happens when you combine a 'Good' DMA IC with a 'Good' CMOS CPU? Anyone tried that? Probably somebody tried, possibly without knowing, an probably is not a problem. It is almost obvious to me that the the DMA problem is caused by a combination of factors. You...

Go to advanced search