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by ijor
Fri Mar 27, 2020 6:30 pm
Forum: News & Announcements
Topic: New document at Atari Museum
Replies: 5
Views: 464

Re: New document at Atari Museum

Hi Christian,

czietz wrote:Interesting. You might remember that I deduced/guessed that the first ASICs for the ST (the -20 models) were from Universal Semiconductor.


I do, and I did remember first time I read the document :)
by ijor
Fri Mar 27, 2020 6:29 pm
Forum: 680x0
Topic: pea versus move.l to the stack
Replies: 12
Views: 454

Re: pea versus move.l to the stack

lp wrote:In my cause I'm using move.l a0,-(sp) to push a pointer.


MOVE.l A0,-(SP) & PEA (A0) are essentially the same and take the same number of cycles.
The main difference, again, is that MOVE affects the flags but PEA does not.
by ijor
Fri Mar 27, 2020 3:42 pm
Forum: 680x0
Topic: pea versus move.l to the stack
Replies: 12
Views: 454

Re: pea versus move.l to the stack

MOVE.L #XXX,-(SP) and PEA ABS.L take exactly the same number of cycles.
MOVE.L Dn,-(SP), if suitable, is obviously faster.
Depending on the case you might be able to use shorter (and faster) PEA addressing modes, such as PEA (XXX).W

PEA doesn't affect the flags, MOVE.L does.
by ijor
Fri Mar 27, 2020 12:54 pm
Forum: News & Announcements
Topic: New document at Atari Museum
Replies: 5
Views: 464

New document at Atari Museum

Curt Vendel released a a couple of new internal memo Atari 1984 documents. They mostly cover the 8-bit family but there are a couple of interesting notes about the ST. This is the web page: http://www.atarimuseum.com/computers/8BITS/XE/xesystems.html This is the relevant document: http://www.atarimu...
by ijor
Mon Mar 23, 2020 5:29 am
Forum: MiSTer
Topic: FX CAST Atari ST core
Replies: 336
Views: 141364

Re: FX CAST Atari ST core

telengard wrote:The core defaults to PAL on my 15Khz and I can't change it. :lol:


15 KHz is currently not supported. VGA output is always scan doubled. It will be supported shortly, but not yet. Sorry.
by ijor
Sun Mar 22, 2020 2:51 pm
Forum: Floppy Disk Preservation
Topic: Floppy Disk Stream Image Repository
Replies: 146
Views: 57278

Re: Floppy Disk Stream Image Repository

Strange that you don't have to disable drive B when the .scp is used though. The environment is different. Steem using its own FDC emulation for SCP files, but it uses Pasti for STX images. It's a buglet in Steem's FDC emulation that doesn't behave exactly like real hardware. Which Steem version ar...
by ijor
Sun Mar 22, 2020 12:27 pm
Forum: Floppy Disk Preservation
Topic: Floppy Disk Stream Image Repository
Replies: 146
Views: 57278

Re: Floppy Disk Stream Image Repository

I also randomly checked one of the other (not mine) dumps, and the Captain Dynamo(5r).zip has a heap of bad (well, they're all in black! and dark red in HxC) sectors on it. I checked it because neither Aufit nor HxC will make a working .stx file from the .SCP. Though, the .scp I dumped works perfec...
by ijor
Sat Mar 21, 2020 7:50 pm
Forum: Coding
Topic: Sync-tricks/fullscreen discussion
Replies: 117
Views: 49780

Re: Sync-tricks/fullscreen discussion

Cyprian wrote:If I understand correctly, there is no way to invoke a reset of the video counter in the middle of the screen, in order to split the screen.


I don't see how you could do that. Again, not without somehow creating an additional VSYNC pulse, which might be doable if you don't mind and you insist.
by ijor
Sat Mar 21, 2020 12:22 pm
Forum: Coding
Topic: Sync-tricks/fullscreen discussion
Replies: 117
Views: 49780

Re: Sync-tricks/fullscreen discussion

What about Video counter? Was it reset as it is done in VBL? I thought about what you're asking some times years when working on Hatari and measuring at which exact video cycle video counters are reloaded and unfortunately it won't work : my idea was to toggle to 60 Hz around line 263 at the place ...
by ijor
Sat Mar 21, 2020 12:21 pm
Forum: Coding
Topic: Sync-tricks/fullscreen discussion
Replies: 117
Views: 49780

Re: Sync-tricks/fullscreen discussion

I did some test with the 4bit hard scroll technique. Here the results (50Hz fullscreen 4 plane side scrolling on ST with about 50% processing time left): https://github.com/frankheisig71/st_side_scrl/ It wasn't as simple as it looks like. Obviously different machines behaves different, when applyin...
by ijor
Fri Mar 20, 2020 1:30 am
Forum: Floppy Disk Preservation
Topic: Floppy Disk Stream Image Repository
Replies: 146
Views: 57278

Re: Floppy Disk Stream Image Repository

Fun School 2 for the over 8's - The Hit Squad. Disk looks like it's got some water damage, but, won't really clean off. It dumped successfully, but looks very jittery, and neither Aufit nor HxC show it as having any errors, but neither hAtari or SteemSSE will load this. Can someone check if it runs...
by ijor
Mon Mar 16, 2020 8:41 pm
Forum: Hardware
Topic: GOEX for ST in the making
Replies: 28
Views: 1762

Re: GOEX for ST in the making

I was going to reply once again, but I think we made our point enough. After all, a high quality yet affordable, Gotek compatible, including speaker and OLED, I'm definitely a buyer.
by ijor
Mon Mar 16, 2020 7:10 pm
Forum: Hardware
Topic: GOEX for ST in the making
Replies: 28
Views: 1762

Re: GOEX for ST in the making

I think Hxc will be a non-issue. If the hardware is as similar to the Gotek, HxC will probably run without any changes and Jeff will do it. I prefer to have choices on the software market. Sorry Simon, but I think you are missing the point. Yes, I think we all agree that is good to have more choice...
by ijor
Mon Mar 16, 2020 12:42 pm
Forum: MiSTer
Topic: Minimig (Amiga) core discussion
Replies: 1312
Views: 285666

Re: Minimig (Amiga) core discussion

... So, that $ffff seems, to be the correct behavior there. Now the question is that all write-only chipset registers exhibit this behavior? Is there a simple BASIC for Amiga where some values can be PEEK-ed out? I know nothing specifically about the Amiga. But almost all legacy NMOS chips use an o...
by ijor
Mon Mar 16, 2020 12:12 pm
Forum: Hardware
Topic: GOEX for ST in the making
Replies: 28
Views: 1762

Re: GOEX for ST in the making

FlashFloppy, and hence all derivatives as well, leverages Jeff's HxC work and software. ... Are you sure? From what I know HxC is closed source, commercial product. Was it open source at some point in the past. The HxC firmware is closed source, but the software is open source. Also Jeff developed ...
by ijor
Sun Mar 15, 2020 8:17 pm
Forum: Hardware
Topic: GOEX for ST in the making
Replies: 28
Views: 1762

Re: GOEX for ST in the making

Looks great. Thanks. However there is one thing that bothers me with all these FlashFloppy derivatives. Quote from the store selling the Goex: Credits: GOEX drive comes preinstalled with latest version of great FlashFloppy firmware by Keir Fraser. Please consider a donation to the developer. FlashFl...
by ijor
Thu Mar 12, 2020 5:02 pm
Forum: MiSTer
Topic: Newbie questions
Replies: 635
Views: 150601

Re: Newbie questions

Sorgelig wrote:With wise use FPGA + HPS can push the limits much further. Retro CPU emulation is better on HPS while video and other parts of chipset is better on FPGA. So i don't agree that we a close to limits, especially on hybrid systems.


Yes, hybrid emulation is a very interesting area.
by ijor
Tue Mar 10, 2020 2:28 am
Forum: MiSTer
Topic: Newbie questions
Replies: 635
Views: 150601

Re: Newbie questions

Mostly because of the operating system, you can miss a frame now and then, yet most software emulation issues are resolved by adding buffers: video sync problem? Add a double or triple frame buffer, audio cracking? Set a bigger audio buffer, etc.. From my humble opinion this where most of the overa...
by ijor
Sun Mar 08, 2020 3:32 am
Forum: Steem
Topic: Lemmings with 2 mice on windows 10 - Atari Steem Emulator?
Replies: 22
Views: 5677

Re: Lemmings with 2 mice on windows 10 - Atari Steem Emulator?

MasterOfGizmo wrote:Wow. Another lesson learned ...


Hats off to your humility. Many people here don't have half of your knowledge but would never reply like this.
by ijor
Fri Mar 06, 2020 7:44 pm
Forum: Hardware
Topic: Megafile 60 problems
Replies: 44
Views: 2635

Re: Megafile 60 problems

Are you in Europe or in the USA? I would be ok with shipping it to Continental Europe, just not the USA. Sorry, I'm not in Europe. Btw, what happens with the floppies? I understand you can't read them on the PC. But they do read fine on the ST? Don't you have your files on floppies, or all the valu...
by ijor
Fri Mar 06, 2020 12:39 pm
Forum: Hardware
Topic: Megafile 60 problems
Replies: 44
Views: 2635

Re: Megafile 60 problems

While I appreciate all the help in your email, I am afraid I am just not knowledgeable enough about Atari, TOS, ACSI, SCSI to feel that comfortable messing around with the Megafile, setting up HD emulators and the like. I just want to get my 1040ST up and running and get all my old programs and dat...
by ijor
Fri Mar 06, 2020 12:09 pm
Forum: Hardware
Topic: Megafile 60 problems
Replies: 44
Views: 2635

Re: Megafile 60 problems

Thanks for this. Problem I have is getting those utilities on a floppy disk that the Atari can read. I have no atari modem and I can’t find a floppy drive for my Windows PC that is compatible with the Atari. Is it possible to buy these utilities on an atari compatible floppy disk. Can you provide a...
by ijor
Fri Mar 06, 2020 3:08 am
Forum: Hardware
Topic: Megafile 60 problems
Replies: 44
Views: 2635

Re: Megafile 60 problems

So if I understand what they are saying, they say that they are confident the only problem is that the stepper motor is misaligned but that otherwise the disk is ok. They also say they can't read anything because they don't have a compatible controller. Honestly, I don't understand how they can be s...
by ijor
Fri Feb 28, 2020 2:12 am
Forum: Hardware
Topic: GOTEC or HXC
Replies: 7
Views: 894

Re: GOTEC or HXC

So as you can see this is not a "power" question.... On the other side, the HxC Gotek firmware is currently more experimental, this is currently my playground :wink: , as it is more retro computing oriented. I am testing/experimenting some new concepts/features. That's why it may appears ...
by ijor
Thu Feb 27, 2020 8:41 pm
Forum: MiSTer
Topic: Newbie with FPGA and MiSTer dev question
Replies: 17
Views: 2264

Re: Newbie with FPGA and MiSTer dev question

I would guess as a buffer that you can pass back to the linux system, maybe a byte sized array of 32 to 64 elements, and from the linux end, if it changes then it outputs it to the console, that way you can place a zero terminated ASCII string and it would be output to the console (unless there is ...

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