WHDLoad on a 68010 CPU: Is It Possible??

[ChaosLord]

Most amiga 500 games expect the trapdoor ram to be at c00000, which is neither chip or fast.

If you have such an A500 then you can mod it so that the trapdoor RAM is CHIPram.

[ChaosLord]

I know several people have said that a 68000 is too slow to run WHDLoad, and I agree with that.  I was curious though....is it possible to run it with a 68010?  I have used this CPU in the past and saw a slight speed increase on some games but I have never tried it with WHDLoad.  Has anybody ever tried it before.  If you have, please give me your results.  Thanks.

A 68010 is exactly the same as a 68000 except:
It was easy to get them a little faster, like 12 or 16 Mhz

If you plug in a 68010 that is running at 7.15909Mhz as the 68000 then all that changes is:
1. Mul#? instructions go significantly faster.  But no self-respecting asm coder uses MUL in a time critical loop  Nevertheless I have seen cracktros run at much higher framerate on a 7Mhz 68010 than on 7Mhz 68000.  Obviously they used Muls to calc their 3D rotating gfx.  Shame on them

2. 68010 has Loop Mode  Very tiny loops can run from internal cache.  Does it really matter to you?  Meh

3. On 68010 the Move SR, instruction is privileged.  That means its ILLEGAL.  So any game that uses it will work on 68000 and blow up on 68010.  Maybe WHDLoad has a fancy patch for this?  Donno.


Bottom line: A 68010 introduces software incompatibilities for only a tiny improvement in speed.  I say it isn't worth it.  But you can do what you want   If I was going to suffer incompatibilities to old badly coded gamez then I would just go ahead and use a 68030 or higher.

I always kept at least 1 Amiga with a plain 68000 for 100% compatibility reasons.

[lassie]

@Lassie

What kickstart ROM is in your A2000?

Hi they have 2.0 ROMS ( 37.175 )

[ChaosLord]

Hi they have 2.0 ROMS ( 37.175 )

What is your experience with WHDLoad and a 1.3 ROM?

A couple of years ago
I was going to set up my old A2000 1MB chip 8 MB fast + some kind of SCSI hard drive controller that maybe works or maybe doesn't as a WHDLoad arcade game center.. but I read somewhere (sounded very authoritative) that WHDLoad would not work on KS 1.3 so I gave up my idea and put my box of 4GB SCSI drives in the closet.

[psxphill]

3. On 68010 the Move SR, instruction is privileged. That means its ILLEGAL. So any game that uses it will work on 68000 and blow up on 68010. Maybe WHDLoad has a fancy patch for this? Donno.

A lot of games run in supervisor mode, which doesn't cause a problem. As this affects all subsequent processors it can't be a big problem, or the games wouldn't run on an 020/030/040/060 either.
 
I'm not sure I'd bother with just swapping a 68000 for a 68010, because it will still run at 7mhz. There are 14mhz hacks, but even these don't make a huge difference & can cause incompatibilities.
 
If you want a faster processor then an accelerator is the best way (I have a blizzard 14mhz 68000 accelerator with fast ram on ebay).

[ChaosLord]

A lot of games run in supervisor mode, which doesn't cause a problem.

Oh really.  I never knew that.  What is the advantage of doing that?

Why would one game do it but another refuse to do it?

 As this affects all subsequent processors it can't be a big problem, or the games wouldn't run on an 020/030/040/060 either.

When 020 first came out I remember a lot of stuff crashing on it in 1987.  donno why tho.  Could have been self-modifying code or illegal instruction.

[lassie]

What is your experience with WHDLoad and a 1.3 ROM?

A couple of years ago
I was going to set up my old A2000 1MB chip 8 MB fast + some kind of SCSI hard drive controller that maybe works or maybe doesn't as a WHDLoad arcade game center.. but I read somewhere (sounded very authoritative) that WHDLoad would not work on KS 1.3 so I gave up my idea and put my box of 4GB SCSI drives in the closet.

I must admit that i have never tried Whdload with KS 1.3 ROM. But i think Whdload Requires minimum 2.0 ROM.

[psxphill]

Oh really. I never knew that. What is the advantage of doing that?
 
Why would one game do it but another refuse to do it?

I don't know why some people switched to supervisor mode, but they did.
 
http://eab.abime.net/showthread.php?t=65247
 

When 020 first came out I remember a lot of stuff crashing on it in 1987. donno why tho. Could have been self-modifying code or illegal instruction.

Yeah, anything running in user mode would crash. Commodore added a call to exec for GetSR() & SetSR() that worked on everything, but not all software used it. However WHDLoad obviously has a solution to the problem as everyone is running 68000 games on 020+.

[Darrin]

I use Whdload in my plain 68000 Minimig in 7Mhz mode (As I did in my A600) and 68000 games run at 68000 speed.

I've never turned off "turbo mode" on my Minimig.  

WHDLoad works like a charm off my ClassicWB HDF file.  It boots off a KS3.1 ROM and I have 1MB to Chip RAM and 2.5MB to Fast RAM.

[gaula92]

I've never turned off "turbo mode" on my Minimig.  

WHDLoad works like a charm off my ClassicWB HDF file.  It boots off a KS3.1 ROM and I have 1MB to Chip RAM and 2.5MB to Fast RAM.

I'd like to do the same, but TURBO mode breaks audio on many games, like Ishar, wich I play often. (Well, in-game sounds are there, but the AWESOME Conan-esque intro music has wrong timming in Turbo mode, and I always start a game getting into mood with that music).

[barney]

What is your experience with WHDLoad and a 1.3 ROM?

A couple of years ago
I was going to set up my old A2000 1MB chip 8 MB fast + some kind of SCSI hard drive controller that maybe works or maybe doesn't as a WHDLoad arcade game center.. but I read somewhere (sounded very authoritative) that WHDLoad would not work on KS 1.3 so I gave up my idea and put my box of 4GB SCSI drives in the closet.

I got my Amiga 2000 to work with WHDLoad with KS 1.3.  I also got Workbench 3.1 to work with KS 1.3.  I wish I could tell you what I did to make it work but I can't.  It just works.

[barney]

I was thinking.  I wanted to install WHDLoad on my Amiga 1000 after I installed a hard drive and added memory.  Now I find out that only 512kb chip ram isn't sufficient enough for WHDLoad.  Now I am wondering whether adding ram to an Amiga 1000 is even feasable.  What would be the point?  Is there a way around the 512kb chip ram barrier on the 1000?

[ChaosLord]

I was thinking.  I wanted to install WHDLoad on my Amiga 1000 after I installed a hard drive and added memory.  Now I find out that only 512kb chip ram isn't sufficient enough for WHDLoad.  Now I am wondering whether adding ram to an Amiga 1000 is even feasable.  What would be the point?  Is there a way around the 512kb chip ram barrier on the 1000?

Now u see why I gave my A1000 away.

u could solder identical ram chips on top of your existing ram chips for an extra 256K chipram  but that does not solve ur problem.

[psxphill]

Now u see why I gave my A1000 away.
 
u could solder identical ram chips on top of your existing ram chips for an extra 256K chipram but that does not solve ur problem.

You'd have to fit a 1mb or 2mb agnus, but they aren't pin compatible. There was an adapter back in the day, but I think it's better to keep things original.

[barney]

What I would really like to do is install an Amiga 500 motherboard into an Amiga 1000 case.  That would definitely get around the 512kb barrier.  But somthing like that would be hard as hell to do.