Questions tagged [emulation]

For questions about processes and software for emulating retro computer and console hardware (e.g. MAME, QEMU).

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1answer
49 views

Does anyone have information about the nj32disk.sys driver?

I'm currently trying to use the nj32disk.sys driver to use my USB stick as a virtual hard drive. The problem is that the driver acts like a floppy disk. My question is: Is there a documentation about ...
1
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0answers
73 views

Do the Tandy CoCo and the Dragon 32 & 64 use all the same disk image file formats?

Tandy's TRS-80 Color Computer "CoCo" and the Dragon 32 & 64 were very similar but not clones and not the same. Floppy disk versions used totally different DOSes and disk layouts. Both ...
2
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0answers
228 views

What is it with DS emulation being so slow?

I have a fairly decent computer, and I have been messing around with DS Emulation recently. I have found that if a game is running on the emulator, and if I have anything else running, the performance ...
3
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1answer
221 views

How can I get MAME to run modified ROMs whose checksums don't match the originals?

In the aftermath of the question about running the arcade Pac-Man ROM on a Sinclair ZX Spectrum I discovered that about the same time that was done, somebody else did the reverse, porting a classic ...
3
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1answer
143 views

`DRAW` instruction timing

I asked a question here about CHIP-8 instruction timing, and this answer mentions that DRAW waits for vblank: For Chip-8 code that draws anything, the limiting factor will be the wait-for-vblank that ...
9
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5answers
1k views

C64 cartridge emulation with ATmega

As a personal project I had the idea to create a custom cartridge for my Commodore 64 and use an ATmega 1284p microcontroller to emulate eproms and/or custom chips. Basically my idea is similar to ...
3
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3answers
385 views

Effective speed of original COSMAC VIP CHIP-8 interpreter

The original CHIP-8 interpreter ran on RCA 1802-based kit computers and home computers, most notably on the COSMAC VIP. Some of the CHIP-8 opcodes are complicated and involve many memory round-trips, ...
3
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1answer
134 views

How does the GameBoy's Memory Controller MBC1 Work in Mode 1?

In short, are banks 20h/40h/60h accessible in mode 1? The Pan Docs state that when in mode 1, those banks become accessible. "...on large carts (using the secondary banking register to specify ...
1
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1answer
132 views

Can I run a network game (Empire Deluxe) that uses NETBIOS? [closed]

I use D-Fend to run the video game Empire Deluxe in full screen mode (1366x768) on a Dell Vostro Core i3 laptop running Windows 10. It works fine. I want to run the game on a second identical laptop ...
-1
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6answers
259 views

What are the advantages/disadvantages of using retro hardware vs. FPGA emulation vs. software emulation? [closed]

As someone who recently become interested in retro home computers of 80's and early 90's I'm wandering what are the differences between using a real hardware, FPGA based hardware emulators like MiSTer ...
7
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2answers
697 views

Build a hardware clone or emulator of Apple II?

These days we are constantly seeing low-cost boards that have huge power (raspberry pi, various arduino-like microcontrollers.) I am hoping I could make, or get, a clone or emulation of an Apple II ...
5
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1answer
94 views

How to get GOTEK to work with CDTV?

I'm trying to connect Gotek drive to my CDTV using external caddy (amitek). The drive has 3 digit LED display, after boot i can see F-F. When I insert Flash drive it detects images on it, I can ...
2
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1answer
98 views

Are there open source Java libraries for reading DSK and EDSK disk image files as used by Amstrad and Spectrum +3 emulators?

I've been working on some modules for the Ghidra reverse engineering tool. Ghidra is written in Java, which I'd always avoided when I was more actively programming so this is an opportunity to learn ...
4
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1answer
90 views

Are there any CHIP-8 games that break if `SAVE` / `RESTORE` *doesn't* change the pointer register?

The CHIP-8 instructions SAVE Vx (Fx55) and RESTORE Vx (Fx65) are originally specified to increment the pointer register I as each register is saved/loaded, so by the end of the instruction, the value ...
7
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1answer
111 views

Understanding the DMK disk image file format used by TRS-80 emulators

DMK is a low-level disk image file format used by TRS-80 Model I & Model III, Tandy Color Computer, Dragon 32 & 64, and MSX emulators. It's capable of representing copy-protected disks and all ...
2
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1answer
79 views

Which Apple II emulators were the first ones each to use the .do and .po “dsk” floppy disk image file formats?

Apple II emulation must have started around 25 years ago but I can't seem to find a history of emulation of the platform. There are several disk image file formats but for now I'm interested in the ...
16
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2answers
2k views

Is there a Commodore 64 emulator that can profile running code?

I am developing some software for the Commodore 64, and I am concerned about its runspeed. Is there an emulator that can report, after running my code, where exactly it spent most of its time? I'm ...
3
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2answers
658 views

How does the RST operation of GameBoy (SHARP LR35902) work?

The GameBoy CPU Manual talks about restart operations on page 116. Each of these operations push the current address onto the stack, and then jumps to a specific address (0x00, 0x08, 0x10, etc, ...
2
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1answer
131 views

What is the file that VICE refers to as dos1541?

VICE needs a file called dos1541 if you want hardware emulation of the 1541 disk drive. What does that file contain, exactly? The 1541 seems to have two ROMs: a DOS and a KERNAL. But if I take the ...
4
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4answers
360 views

Would having the console's CPU help in emulation hypothetically?

If I had a hypothetical computer just like nowaday's computers, but it had an NMOS 6502, would it provide me with a better emulation experience than if I were to emulate the 6502 inside software? Also,...
23
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2answers
4k views

How to convert Amiga DMS to ADF?

Our demoscene group managed to release only one demo before it fell apart, but these being the early days of the Internet in my country, and me getting lucky with obtaining access to it and creating ...
7
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1answer
459 views

Is there a MIME type for C64 .PRG files?

I'm writing an emulator with an HTTP API that could usefully accept C64 .PRG files as the request body of a POST request. This means it has to be able to detect such files by their MIME type: POST ...
8
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1answer
465 views

Was there ever a functional EGA emulator for the Hercules graphics card?

I used to use a CGA emulator (don't remember which one it was), that could show some gfx even in EGA/VGA-only games (when I selected EGA mode). I remember my frustration seeing some garbled graphics ...
0
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1answer
85 views

Do any of the open source Sinclair ZX Spectrum emulators support both TR-DOS and 3DOS?

The number of Spectrum emulators has been growing for decades now so there's quite a lot for different platforms and written in different languages. I'm interesting in learning about two of the disk ...
14
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1answer
347 views

Could suitably-written Apple-I software force bytes into the display shift register, and do modern recreations emulate that?

The original Apple I didn't use RAM to hold the contents of the display, but instead used a group of six 1024-bit shift registers to hold the display contents and a seventh 1024-bit shift register to ...
7
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2answers
582 views

Why does the .z80 emulator-snapshot format have separate fields for the 8-bit refresh register and bit 7 of R?

I've been looking at the .z80 file format for Sinclair ZX Spectrum games. Most docs discussing the format include pretty much this wording: Offset Length Description -----------------------...
3
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1answer
240 views

How to emulate Pocket PC (PPC) 2003?

The OS is at least 17-18 years ago. Yet there is a lot of scattered information and dead ends, and no clarity on how to emulate Pocket PC 2003, the early precedent to Windows Mobile. How to emulate ...
24
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6answers
10k views

Can x86 processors run 8-bit applications?

I was wondering if it is possible to run 8-bit applications within QEMU. I know that the x86 architecture can run 16-bit applications, but can it also run 8-bit applications?
3
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2answers
135 views

How do I navigate the boot menu in later model Spectrum emulators?

35 years ago I had an original 48K Sinclair ZX Spectrum. I never had any of the Plus or 128K models and practically never even touched one as I moved onto the Amiga quite early. I'm now playing with ...
6
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2answers
344 views

Are there standalone emulators of Applesoft Basic?

My only retrocomputing desire is to program in Applesoft Basic and relive the Apple II days from the 1980's. Playing games is of no particular interest to me. I just want to use a keyboard, not a ...
6
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1answer
2k views

Converting ZX Spectrum .ipf files to .z80 or .tzx for use in Fuse on RetroPie?

I have a 'perfect' set of ZX Spectrum games (in .ipf format) that I would like to use in EmulationStation (RetroPie) but the Fuse emulator doesn't recognize .ipf files. Are there any tools that will ...
16
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5answers
3k views

Why are different emulators needed to run platforms that use 6502 assembly code?

To my knowledge, an emulator turns machine code for a console into something that your computer can understand. For example, assembly code from a Gamecube game is not the same as from a .exe file. ...
1
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2answers
212 views

How to get rid of keyboard latency in atari800 emulator?

I use the atari800 emulator v. 4.2.0 on windows 10 and linux in latest version. (https://atari800.github.io) I notice an annoying keyboard latency of up to 100-200ms (keypress-to-click and ...
14
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2answers
765 views

Does the Z80 allow interrupts after processing and ignoring a 0xdd prefix?

I read here that if the Z80 encounters e.g. multiple 0xdd prefixes in sequence, for each 0xxdd except the last it acts almost like a NOP, but does not allow interrupts to occur immediately after "...
8
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1answer
2k views

NES chips usage

I am curently studying NES architecture to create a NES emulator. While looking up the NES motherboard schematics (https://console5.com/wiki/Nintendo_NES-001), some of the chips usage are not clear to ...
12
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2answers
645 views

Where to upload the odd and rare emulators and related to them ROMs & software?

Over time, I collected some rare and interesting emulators and their roms and software for, for example, region specific computer machines, rare 1-2 gen consoles and what not. Many of these emulators ...
19
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6answers
5k views

How can I emulate MS-DOS on OS X?

I am looking for a emulator for MS-DOS for OS X to run old games on. Are there any free emulators for MS-DOS that run on an Apple machine with OS X?
7
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2answers
441 views

Get exact position of raster beam on C64/C128

By reading register $D012/$D011 or when pausing the execution of an emulation in VICE starting the monitor and entering io d000, it is possible to get information about the current rasterline. For ...
17
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4answers
2k views

80286 real mode emulator for 8086

While trying to use a "modern" sound card (an Aztech Sound Galaxy Pro 16 II) in an XT compatible 8086 computer, I encountered the problem that the drivers and tools (like the mixer initialization tool ...
27
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5answers
5k views

Why are Windows 95 installation disks not uniquely bound to a single product key?

I was installing the OEM version of Windows 95 on VirtualBox the other day for reminiscence sake, and for some reason I had two different product keys. I tested both of them to see which one mapped to ...
2
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2answers
236 views

Is there such thing as para-emulation? [closed]

Is there such thing as a para-emulation? Like para-virtualization but for emulation? If so, where could I find a website that describes it?
25
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2answers
7k views

How does the Gameboy Link Cable work?

I've been looking into implementing Gameboy Link Cable compatibility into Bizhawk (which does not support it yet) using Lua. The problem is that I can't find any mention of how it works online. I ...
8
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3answers
1k views

How to develop software for the Commodore 64 with VICE?

I see a very large fan-base and hear a lot (especially here on retrocomputing) about how great the Commodore 64 was. Growing up in the Windows 95/98 era, I seemed to have missed a great era for ...
11
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2answers
888 views

How to convert Atari (65XE) tapes to ATR?

I still have some tapes for my Atari 65XE and I'd like to play some of the old games I got. But I don't have the Atari anymore. I have a tape recorder of quality surpassing the Atari one by quite a ...
13
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1answer
868 views

Does the Commodore CDTV-CR contain a 65C02 for some reason?

Browsing around the FS-UAE source code I discovered a 65(S)C02 emulation core, which appears to not be referenced anywhere outside of some CDTV-CR related source file. Apparently, a CDTV is ...
6
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7answers
1k views

What systems had the lowest resolution ever that still allowed games to be made?

Just for fun, I wrote my own Chip8 interpreter/emulator and it works. The point is that it works in the terminal, meaning that a pixel is rendered using curses and a # character. For the Chip8 that'...
2
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2answers
341 views

emulator library that allows to partially emulate old games [closed]

EDIT: previously I added a lot of examples to this questions. I removed the examples, because the question was voted to be "too broad", so I put more emphasis on the question again. Question: Is ...
7
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1answer
4k views

Symbian emulator to run Ngage games

I don't really know if this is the correct place to ask this, if not let me know where I should. I would like to know if it would be possible to run Ngage games on an existing Symbian emulator. There ...
5
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3answers
515 views

Can someone explain this algorithm used to compute the auxiliary carry flag?

I'm debugging my 8080 emulator and I've gone the route of comparing it to the output of another tested emulator to see where I went wrong. When calculating the auxiliary carry flag, I used this ...
60
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10answers
8k views

What makes accurate emulation of old systems a difficult task?

Thanks to a lot of passionate and skilled people, we can emulate pretty much any retro platform today. For most people they perform well enough, but in fact, a substantial amount of these emulators ...