Java Emulator

Discussion and advice about emulating the QL on other machines.
RWAP
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Java Emulator

Post by RWAP »

This follows on from the introduction by zeccie - see http://www.qlforum.co.uk/viewtopic.php?f=8&t=170#p888

Zeccie expressed an interest in programming a Java based Sinclair QL emulator.

A Java based emulator is something I have been wanting for years, but unfortunately, there has just not been the expertise / willingness in the QL community to write one. The main benefit of a Java based emulator, so far as I can see, would be being able to add it to websites about the QL, so that people could try out different games / software.

I did wonder if it could possibly be based on one of the generic 68000 java emulators, or if there is a Java based Amiga emulator, which could then maybe be amended to run QDOS4Amiga ?
Last edited by RWAP on Tue Jul 12, 2011 5:58 pm, edited 1 time in total.


zeccie
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Re: Hi all from the Netherlands

Post by zeccie »

Hi RWAP,

I googled "java emulator amiga" and I found this link: https://github.com/tonyheadford/m68k, looks promising! I'll have a try to see if it can read a ql rom without too may mistakes.

Chris


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dilwyn
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Re: Hi all from the Netherlands

Post by dilwyn »

zeccie wrote:Of course I have been playing with some emulators throughout the years. I saw a post about an iPad running Qlay (I think). I was wondering if anybody ever considered trying to build an emulator written in Java, so it could be run on an Android with some modifications. As far as I know, the Apple App store prohibits emulation software. If anyone is interested I would be more than happy to contribute. I have a lot of experience with Java programming, being a CS lecturer at the university. I know it would be a big project, but a lot of code already exists and needs to be ported to Java.
I think what you saw was an iPad running DOS emulation in turn running a QL emulator. IIRC it was Mr Navigator. However, I think Apple forced the removal of the DOS emulation app in no time and all and it was no longer possible.
I have long since wished to be able to run a Java QL emulator in a website. I remember seeing a ZX81 emulator running in this way. There are Java-based 68000 emulators out there, and the sources to a number of QL emulators plus commented ROM disassemblies are available too to help with such a project. Good luck, Chris, if you do get involved with such a project.
Dilwyn


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dilwyn
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Re: Hi all from the Netherlands

Post by dilwyn »

zeccie wrote:Hi RWAP,

I googled "java emulator amiga" and I found this link: https://github.com/tonyheadford/m68k, looks promising! I'll have a try to see if it can read a ql rom without too may mistakes.

Chris
If it helps, there are a number of QL ROM images available to download from my website at http://www.dilwyn.me.uk/qlrom/index.html along with some QL ROM disassemblies.

I've put an appeal for anyone else willing to cooperate on this into the next issue of Quanta which we are preparing this week, and wonder if QL Today could do the same if anyone from that magazine is reading this?

Dilwyn


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dilwyn
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Re: Hi all from the Netherlands

Post by dilwyn »

dilwyn wrote:
zeccie wrote:Hi RWAP,
I googled "java emulator amiga" and I found this link: https://github.com/tonyheadford/m68k, looks promising! I'll have a try to see if it can read a ql rom without too may mistakes.
Chris
If it helps, there are a number of QL ROM images available to download from my website at http://www.dilwyn.me.uk/qlrom/index.html along with some QL ROM disassemblies.
I've put an appeal for anyone else willing to cooperate on this into the next issue of Quanta which we are preparing this week, and wonder if QL Today could do the same if anyone from that magazine is reading this?
In case it is of any help, there is a Java Spectrum emulator including sources to download at http://www.devili.iki.fi/pub/emulators/Sinclair/


zeccie
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Java emulator boots... well sort of ;-)

Post by zeccie »

Hi all,

Well, I have been messing around with the M68000 emulator in the link I posted and within an hour(!) I had a booting JM.rom! However, it got through the memory check (so you can see the famous startup pattern appear and disappear as I had made a GUI based on the screen part of the memory, it was a funny thing to see), but then the emulator stops at some opcode. I have been looking at it, and it seems that there might be a bug in M68000 emulator, mixing up the USP and SSP . Anyway, somehow the PC gets a wrong value of -1 and I wouldn't call that a correct value ;-). I'll dive into it shortly as my holiday starts Wednesday.

Help in any way is appreciated, so the mention of it in Quanta is great! However, something else isn't that great: I showed the startup screen of the emulator (well, version alpha alpha ;-)) to my girlfriend, and then plugged my real QL in to show the real screen....and now the QL is in coma...... It looks if there is a TV signal, but is black. Has anyone a clue what might be broken (is it RAM maybe?).


RWAP
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Re: Hi all from the Netherlands

Post by RWAP »

At least you are getting somewhere :)

As for the QL - have a look at
http://www.qlforum.co.uk/viewtopic.php?f=2&t=104

This was a similar issue - RAM is most likely the problem however.


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dilwyn
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Re: Java emulator boots... well sort of ;-)

Post by dilwyn »

zeccie wrote:Hi all,

Well, I have been messing around with the M68000 emulator in the link I posted and within an hour(!) I had a booting JM.rom! However, it got through the memory check (so you can see the famous startup pattern appear and disappear as I had made a GUI based on the screen part of the memory, it was a funny thing to see), but then the emulator stops at some opcode. I have been looking at it, and it seems that there might be a bug in M68000 emulator, mixing up the USP and SSP . Anyway, somehow the PC gets a wrong value of -1 and I wouldn't call that a correct value ;-). I'll dive into it shortly as my holiday starts Wednesday.

Help in any way is appreciated, so the mention of it in Quanta is great! However, something else isn't that great: I showed the startup screen of the emulator (well, version alpha alpha ;-)) to my girlfriend, and then plugged my real QL in to show the real screen....and now the QL is in coma...... It looks if there is a TV signal, but is black. Has anyone a clue what might be broken (is it RAM maybe?).
Congratulations on getting this far with it already. I have mentioned the project in Quanta magazine next issue and appealed for anyone willing and able to help you. I've also emailed QL Today magazine to ask if they would mention this too. I think it'd be a really valuable QL project which would make it easy for ex-QLers and retro enthusiasts to use QL software and become involved with the QL. Good luck.

Dilwyn


RWAP
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Re: Hi all from the Netherlands

Post by RWAP »

I really want a Java emulator - it would be great to add to the QL Wiki the ability for people to try out each of the QL programs (maybe a time limited basis?)


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dilwyn
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Re: Hi all from the Netherlands

Post by dilwyn »

RWAP wrote:I really want a Java emulator - it would be great to add to the QL Wiki the ability for people to try out each of the QL programs (maybe a time limited basis?)
Do you think we could post a request on the ql-users list to ask for help for Zeccie? Or best to keep it local here for a bit to give him a chance to look at the project?

Dilwyn


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