Search found 3011 matches

by ijor
Thu Jan 23, 2020 4:54 pm
Forum: Floppy Disk Preservation
Topic: Floppy Disk Stream Image Repository
Replies: 82
Views: 41457

Re: Floppy Disk Stream Image Repository

Fair enough. (Just asking: how come the KF dumps are so much larger then, file size wize?) The size of the dumps doesn't have much to do with the sampling accuracy. It depends more on the file format and the encoding. Anyway, KF and SCP dumps should be about the same size. Are you dumping 5 revolut...
by ijor
Thu Jan 23, 2020 4:37 pm
Forum: MiST
Topic: It's no more a MiSTery
Replies: 279
Views: 39378

Re: It's no more a MiSTery

No, I haven't tried with other than the monitor that I currently setup with the MiST. Perhaps I should try another one . The monitor I'm using (Benq XL2411T) seems to run everything else I've thrown at it. Sync signals are usually taboo in the ST world, but some demos are messing with them (maybe b...
by ijor
Thu Jan 23, 2020 4:14 pm
Forum: Applications
Topic: Req : "Audio Sculpture" (STX,...) even not running...
Replies: 202
Views: 35701

Re: Req : "Audio Sculpture" (STX,...) even not running...

As described in my document I am also trying to differentiate “sector write splice” from “track write splice”. To be able to make the distinction between the two requires high-level analysis. The reason for detecting sector write splice is to be able to detect if a FD has been modified (tampered). ...
by ijor
Thu Jan 23, 2020 1:36 pm
Forum: Floppy Disk Preservation
Topic: Floppy Disk Stream Image Repository
Replies: 82
Views: 41457

Re: Floppy Disk Stream Image Repository

I spent a little bit of time talking to the guys on the Video Game Preservation Society, and it looks like the GW/Supercard Pro doesn't image the disks at a high enough resolution for preservation, unlike the Kryoflux. So, I may need to do this all again, with a KF. Tch :) Exactly who told you that...
by ijor
Thu Jan 23, 2020 3:04 am
Forum: Floppy Disk Preservation
Topic: Floppy Disk Stream Image Repository
Replies: 82
Views: 41457

Re: Floppy Disk Stream Image Repository

I've put together my Greaseweazle, and made a few dumps ... Is there anywhere in particular you want this? (Or, indeed, all of these?) Hi, thank you very much. Yes, if you can dump and upload all the original disks you have, that would be great. Please label each image with as much information as p...
by ijor
Thu Jan 23, 2020 2:08 am
Forum: 680x0
Topic: Data register sign extension
Replies: 5
Views: 157

Re: Data register sign extension

The 68000 never modifies just the low word of an address register. This is part of the 68K philosophy and probably well known. The MOVEM instruction is rather unique in that it doesn't distinguish between address or data register destinations. So the principle of sign extension is applied in either ...
by ijor
Thu Jan 23, 2020 1:53 am
Forum: Applications
Topic: Req : "Audio Sculpture" (STX,...) even not running...
Replies: 202
Views: 35701

Re: Req : "Audio Sculpture" (STX,...) even not running...

Hi Jean, But most of my problems are related to write splice detection ... So if Ijor is still looking at this thread I have a question for him (actually anybody is welcome to answer): Can you explain simply what is the best way to detect the write splice. I am currently using a very complex process...
by ijor
Tue Jan 21, 2020 6:33 pm
Forum: Games - General
Topic: Dungeon Master Copy Protection
Replies: 3
Views: 1687

Re: Dungeon Master Copy Protection

Sorry for the late follow up. I missed this thread ... Quite a few mistakes there... 3. Rob Northen protection wasn't based on a protected "long track" with no sectors, it was a single protected sector with non-standard data rate within that sector There is an early Copylock/Rob Northen co...
by ijor
Tue Jan 21, 2020 6:23 pm
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 305
Views: 118393

Re: FX CAST Atari ST core

... though the aspect ratio is still broken .. but I suspect thats due to not having the updated framework with the scaler and such. So unfortunate that this core is so close but a few key features dont work and it still lacks proper framebuffer support so it has that weird default video mode that ...
by ijor
Thu Jan 16, 2020 3:51 am
Forum: 680x0
Topic: Understanding the Union Demo's Opening of left and right borders
Replies: 37
Views: 3699

Re: Understanding the Union Demo's Opening of left and right borders

I've adjusted it to "a latency in being signalled to the MFP and in the MFP responding to the change in its input" to clarify that I don't think electrons are somehow having a bit of a nap halfway along a trace or anything like that. I intend this to be consistent with your comment elsewh...
by ijor
Wed Jan 15, 2020 7:51 pm
Forum: 680x0
Topic: Understanding the Union Demo's Opening of left and right borders
Replies: 37
Views: 3699

Re: Understanding the Union Demo's Opening of left and right borders

I strongly disagree. Furthermore, it's a wiki so there's a full edit history so nothing has been lost. If someone else agrees with you and wants to do something about it then it's an easy fix. So — obiter — even if I did agree, it would be invalid to argue that any damage had been done. Amongst the...
by ijor
Wed Jan 15, 2020 12:31 pm
Forum: Pasti & VAPI
Topic: New version of Pasti.DLL: 0.3a
Replies: 15
Views: 19221

Re: New version of Pasti.DLL: 0.3a

Is there any option to include support for Pasti images in FlashFloppy and/or HxE? I'm sure it would require a cooperation of developers on both "sides". HxC already supports Pasti images, although with some limitations. The GUI software can convert Pasti images to its native HFE format, ...
by ijor
Wed Jan 15, 2020 12:54 am
Forum: 680x0
Topic: Understanding the Union Demo's Opening of left and right borders
Replies: 37
Views: 3699

Re: Understanding the Union Demo's Opening of left and right borders

Sorry, yes, I understood those answers already — you were very clear and informative. So if you know the answers, then why you are that vague: They will not necessarily occur simultaneously. You know they are not simultaneous. Why using such phrasing that is not conclusive? Sorry, but to be honest,...
by ijor
Tue Jan 14, 2020 7:54 pm
Forum: Coding
Topic: What is $60 for?
Replies: 14
Views: 4223

Re: What is $60 for? spurious interrupt

As I described already, a spurious interrupt would happen if you disable an interrupt after the CPU already decided to trigger the interrupt exception. The CPU takes the decision to take an interrupt a few cycles before the end of an instruction. Suppose an MFP interrupt it is just going to be pendi...
by ijor
Tue Jan 14, 2020 5:35 pm
Forum: Website Discussions
Topic: using external floppy disc drive to tranfer
Replies: 2
Views: 449

Re: using external floppy disc drive to tranfer

Will an external drive allow me to do this. Is there a recommended unit that works, no fuss. Some USB drives work, other do not because they don't support Double Density at all (HD only). Nowadays most brand new USB drives are OEM, and then here is no reliable way to know beforehand if it works or ...
by ijor
Sat Jan 11, 2020 10:46 pm
Forum: 680x0
Topic: YACHT, MULU # and an extra program fetch
Replies: 13
Views: 4681

Re: YACHT, MULU # and an extra program fetch

Questions (I've never used a FPGA) about doing that: - What free tool is recommended for the simulation (extra points if on Windows)? Quartus? ModelSim, the simulator included with Quartus is excellent and it's free. You don't need to download or install the full Quartus, just the simulator. Yes, i...
by ijor
Fri Jan 10, 2020 1:03 pm
Forum: Coding
Topic: Blitter Execution Times
Replies: 25
Views: 1322

Re: Blitter Execution Times

I mean accessing e.g. addresses between 0x400000 and 0xDFFFFF, or in general any memory region for which no DTACK is generated but eventually a bus error is generated by Glue. Ah, yes. And this includes not only addresses that provoke a Bus Error when accessed by the CPU. Same timing would happen i...
by ijor
Fri Jan 10, 2020 1:29 am
Forum: 680x0
Topic: Understanding the Union Demo's Opening of left and right borders
Replies: 37
Views: 3699

Re: Understanding the Union Demo's Opening of left and right borders

Especially as I think you've already been extremely helpful, and evidently I haven't been the best at asking questions, I'm hoping that a more thorough search of this forum's archives is going to throw some light on things. I think I understand your questions, and I think I answered them already. B...
by ijor
Fri Jan 10, 2020 12:08 am
Forum: Coding
Topic: Blitter Execution Times
Replies: 25
Views: 1322

Re: Blitter Execution Times

Semi-on-topic: Hatari also differs significantly from real hardware with respect to the timing when blitting from or to a non-existing memory region. This is certainly a corner case, because why would someone do that... Non-existing memory region? Like accessing the 2nd MB on a machine with 1 MB RA...
by ijor
Thu Jan 09, 2020 11:59 pm
Forum: Coding
Topic: Blitter Execution Times
Replies: 25
Views: 1322

Re: Blitter Execution Times

In the post describing the tests I have performed, when I talk about setting the value of Xcount to 1, it is for SKEW=0. As soon as the SKEW is set to a value different than 0, the program automatically increments Xcount (and sets NFSR). So I have not tested the case you mention (Xcount=1 and NFSR ...
by ijor
Thu Jan 09, 2020 4:36 am
Forum: 680x0
Topic: Understanding the Union Demo's Opening of left and right borders
Replies: 37
Views: 3699

Re: Understanding the Union Demo's Opening of left and right borders

It was meant to communicate only: there'll be delays, but I'm not going to tell you what they are, or even whether they're the same for every row. I'm not sure there is any need to be that vague, at least regarding the simultaneity of multiple signals affected on the same row. Considering there is ...
by ijor
Thu Jan 09, 2020 2:17 am
Forum: Coding
Topic: Sync-tricks/fullscreen discussion
Replies: 104
Views: 41957

Re: Sync-tricks/fullscreen discussion

Hi Gunstick!

Gunstick wrote:I found that the 0 byte length was unstable, so I never used id.


This switch requires code that considers the current wakeup state and adapts the timing accordingly.
by ijor
Thu Jan 09, 2020 2:13 am
Forum: Coding
Topic: Blitter Execution Times
Replies: 25
Views: 1322

Re: Blitter Execution Times

But for cases where SKEW/NFSR are set and the right mask is forced to $FFFF, I have found some discrepancies. Hatari and Steem do no perform the same number of memory accesses ! As I said already, NFSR doesn't force a destination read, which seems what Hatari is doing wrong. That seems to be the di...
by ijor
Tue Jan 07, 2020 9:45 pm
Forum: Coding
Topic: Blitter Execution Times
Replies: 25
Views: 1322

Re: Blitter Execution Times

What really matters in the end is how many words you read /write, which can be a consequence of the logical operation, or the value xfsr/nfsr, or the value of the mask. Right. For completeness I should add SMUDGE setting as well. It is true that there is no much point in using NFSR without a mask ....
by ijor
Tue Jan 07, 2020 12:14 am
Forum: Coding
Topic: Blitter Execution Times
Replies: 25
Views: 1322

Re: Blitter Execution Times

I tell you I am surprised because for me there should not be any difference for the blitter between using: - the mode 7 (source OR destination) - the mode 3 (source) with mask different of $FFFF In both cases this corresponds to doing a OR, and the first case requires 12 cycles, whereas the second ...

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