WHDLoad hell

[Eamoe]

Hi all,

I've finally come around to building me some decent WHDLoad machine.

- A500 rev 6A
- Amigakit's kickstart switcher
- A590 with SCSI-->IDE-->CF 2GB + 2MB RAM
- M-Tec 68020-i + 4MB RAM
- 4MB Eureka RAM Expansion board

With WB3.1 started and idle, I have about 1MB chip and 8MB fast RAM. But.

I get hell trying to do anything with WHDLoad. Usually it crashes during the games install process (I now use InstallerNG -- to no avail). And not always in the same way. Sometimes I get guru, sometimes both RAMs drop to zero and everything but the pointer and GUI buttons freeze. There's one game which I managed to install, but it crashes after the WHDLoad credit window.

I've tried many and haven't been able to play any yet. Just how do you guys do it?! Am I doing something wrong?

Note about RAM
I notice some strange RAM behavior, certainly due to mixing all these expansions. Example: the M-Tec and the Eureka both use a little software to add fast RAM. Well if I disconnect one and use the other's software, RAM gets added anyway. I haven't tested all solutions (3 expansions + 2 programs = loads of possible combinations...), but I don't get results which are very clear in terms of total RAM quantity.

See this little addition:

512k onboard
+ 4MB M-Tec
+ 4MB Eureka
+ 2MB A590
= 10.5MB

but I only get to see a total of 9MB at most. Weird.

Note about extra chip RAM
This Eureka board has a Gary adaptor board. I think it's supposed to allow 512k extra chip RAM. I bridged JP2 pads 1-2 and soldered the wire from the Gary adaptor to this bridge. Before I did this, I had 10MB fast and 512k chip, which is the correct count. But I need 1MB chip to play WHDLoad games...

So why does WHDLoad crash all the time?
It's certainly a RAM problem, no? Like overlapping addresses or something? (I have no idea what I'm talking about) Anyone has an idea?

[Antti]

Originally Posted by Eamoe

Like overlapping addresses or something? (I have no idea what I'm talking about) Anyone has an idea?

Run ShowConfig. It willl show you the addresses that each expansion is using.

[musashi5150]

Originally Posted by Eamoe

Usually it crashes during the games install process

That's the first clue - if it crashes while running an installer script then it looks like a much wider system problem than just WHDLoad. Have you tried running some RAM test tools?

[zipper]

I think that M-tec accelerator puts its memory into 24bit space like the other expansions so you are boldly trying to put 10.5 MB into 8 MB space...

[Eamoe]

I am at work right now and can't check right away. I will when I have time to do so. To reply:

Originally Posted by Antti

Run ShowConfig. It willl show you the addresses that each expansion is using.

I'll do that.

Originally Posted by musashi5150

Have you tried running some RAM test tools?

Had a bad chip on the Eureka which I replaced. Haven't tested again though. Could a failing chip cause such trouble?

Originally Posted by zipper

I think that M-tec accelerator puts its memory into 24bit space like the other expansions so you are boldly trying to put 10.5 MB into 8 MB space...

Nope. The little "add32bit" app pretty much says what it does (had it been called "add24bit", I'd have agreed ).

For my own education... what is a 24bit space compared to a 32bit one? I understand RAM can be used in different ways: chip or fast, 24 or 32 bit... this totally puzzles me.

[Amigafanboi]

Just because it's 24 bit doesn't mean it is out of the zorro 8mb limit, for instance the commodore a2630 adds 32bit ram but it still lays in the 8mb limit.
You should try limiting your memory to 8mb overall first before troubleshooting anything else.

Edit: the mtec memory does lay in the 8mb limit so that's your problem right there...drop all your ram to 8mb or you'll just get random errors and crashes.

[Retro1234]

Maybe someone can link you to Pre-installed WHDload games - this would make testing quicker.

[zipper]

full 32bit has possibility for 4 GB memory space; the lower processors (020 EC version )had just 24 address lines supporting max 8 MB of memory.

[Eamoe]

Originally Posted by Amigafanboi

drop all your ram to 8mb or you'll just get random errors and crashes.

Yeah, it's really RANDOM crashes, I never get to see twice the exact same.

Originally Posted by zipper

full 32bit has possibility for 4 GB memory space; the lower processors (020 EC version )had just 24 address lines supporting max 8 MB of memory.

I can't exactly remember my course of action, but I do remember testing with some expansions removed and having no success either. Anyway, I'll do more testing and post results.

For now, thanks to all of you .

[Eamoe]

Hi all,

post to let you know that the Miggy now runs WHDLoad just fine. Removed the 4MB trapdoor expansion. Some RAM chips on it tested faulty. So I guess I had two problems here: memory beyond the 8MB limit + faulty chips.

BTW, is there a method to hard-test 256x4 RAM chips? I mean, the software I use to test RAM doesn't let me determine exactly which chip has errors, and it really would hurt to throw 32 of them in the bin...

[orange]

you can swap one by one and test. that's what I do.
otherwise, you should know how exactly its organized on the expansion, see where traces go, note down bad memory addresses and deduce..

[Eamoe]

OK orange, I guess I'll go by the first solution...

[rkauer]

A way to tell about plucked memory chips is touching them. Bad memory chips use to heat a lot.

[Eamoe]

I'll give this a shot.

[AndyLandy]

Originally Posted by Amigafanboi

Just because it's 24 bit doesn't mean it is out of the zorro 8mb limit, for instance the commodore a2630 adds 32bit ram but it still lays in the 8mb limit.
You should try limiting your memory to 8mb overall first before troubleshooting anything else.

Edit: the mtec memory does lay in the 8mb limit so that's your problem right there...drop all your ram to 8mb or you'll just get random errors and crashes.

Strictly speaking, there are two different things at play here, addressing the RAM and accessing it:
68000 has a 24bit addressing (i.e. up to 16MB -- Your Z2 limit comes since 8MB of that is allocated elsewhere) and 16bit access (i.e. you write 16 bits at a time)
68EC020 has 24bit addressing but 32bit access, this is why an unaccelerated A1200 can only take 8MB FastRAM, despite it being 32-bit accessible. The same is true of the A2630 and a few low-end A1200/030 CPU cards.
68020+ has 32bit addressing and 32bit access. That's up to 4GB of RAM with 32bit access. Shiny!

The theoretical maximum RAM you can put on an Amiga with 24bit addressing is 2MB of ChipRAM, 1.5MB of 'slow fast' (trapdoor RAM) and 8MB of Zorro II RAM. If you start wedging more than 8MB into the Z2 space, things will go badways!

Hope that helps explain a few things. :-)

[Eamoe]

Thanks! I guess it explains much to some, only little to me .

Still haven't really grasped the idea of "slow/fast RAM". How could it be slow and fast at the same time? Nor do I understand all the different memory types -- how many are there in total? And why do memory types on the Amiga bear names based on speeds? Is this only true that one is "faster" than the other?

I've always been very confused with this.

[rkauer]

The Amiga can have FOUR types of memory:

-Graphics/chip RAM: it is the bottom 2Mb the A1200/4000 have. It is shared with all the custom chips (video and sound, that's why it is slow), and is managed by the Agnus/Alice chip.

-FAST-SLOW, also know as RANGER MEMORY: not a true FAST RAM, it is on the A500 address space for trapdoor RAM (0xC00000). Only up to 1.8Mb can be squeezed on this space and is used only in pre-AGA Amigas (one or two A1200 RAM expansions use this area to add one more Mb RAM to the trapdoor) . It is managed by Agnus/Alice (albeit custom chips can't access it), hence why it is slow.

-Zorro 2 RAM: RAM installed after the first 8Mb address space.

It is called also 24bit FAST RAM, and give a nice boost compared to an Amiga with only CHIP memory (around 33% on 68000 Amigas, 133~150% on A1200).

Can have up to 8Mb in size. 4Mb of this address range is shared with the PCMCIA port on A600/1200, so you can add only 4Mb of this kind of RAM and keep using the PCMCIA port.

Amigas without PCMCIA can use this area with no issues at all.

This memory is accessed only by the CPU, that's why it is FAST.

-32bit FAST RAM: is the RAM on accelerators, totally out of the 24bit address range (the first 16Mb) and when used on the Amiga in conjunction with a 030 or better CPU will make the Amiga have a boost of 5 to 50x!

[AndyLandy]

Originally Posted by Eamoe

Thanks! I guess it explains much to some, only little to me .

Still haven't really grasped the idea of "slow/fast RAM". How could it be slow and fast at the same time? Nor do I understand all the different memory types -- how many are there in total? And why do memory types on the Amiga bear names based on speeds? Is this only true that one is "faster" than the other?

I've always been very confused with this.

Chip RAM is accessed by the custom chips, most notably the graphics one. Workbench even calls it 'graphics mem'. I believe it runs at the same speed as the custom chips, so it's not terrifically fast. It's limited to 2MB and lives at the bottom of the address range.

Fast RAM comes in a few different flavours, but ostensibly is only accessible by the CPU, the custom chips can't read or write directly to it. As such, it can run at much faster speeds than the custom chips, hence the name Fast RAM. Workbench calls this 'other mem' (Note the 'can', it doesn't have to run faster)

Slow RAM is what you put in the trapdoor of an A500. It's not Chip RAM, because the custom chips can't access it, but it's not really Fast RAM either, since it runs at the same speed as the Chip RAM. It's most definitely 'other mem', but not strictly Fast RAM. It often gets called Fast RAM as the term informally means "Any RAM that isn't Chip RAM, even if it's dog slow"

For the ultimate in ironic 'Fast' RAM, put a PCMCIA SRAM card into an A1200, you'll get your extra 'Fast' RAM, but the A1200 will run at about 2/3 of its normal speed, because it's actually slower than the Chip RAM. Crazy, huh?

[Eamoe]

@rkauer, @AndyLandy

Thanks guys, this clears it up quite a bit. I understand why I've been confused all this time.