Kickstart 3.1 versions -- What's the difference

AndyLandy

Acceleration!
Joined
Aug 29, 2009
Posts
9,898
Country
UK
Region
Southampton
I notice that Kickstart ROMs for the A500/A600/A2000 are all the same (Presumably because the motherboards for those systems are of similar design) but this isn't the case for the A1200/A3000/A4000. I know these systems require Kickstart split across two chips (I am led to believe this is because the ROMs are 16-bit, but those Amigas need 32-bit, hence two chips) but how come they are different for the three models?
 
Re: Kickstart 3.1 versions -- What's the difference

@Andy

Not to answer your question but to add to the confusion - there are 2 different sets of 3.1 for the 4000. One for the original tower and one for the desktop.

I think the major differences are to do with the SCSI and IDE - but I'm not sure on that :shhh:

Dave G 8)
 
Re: Kickstart 3.1 versions -- What's the difference

Drivers for a specific chipset, the different IDE interfaces and the Zorro and fast slot buses. I know certain ones, like the 500/600/2000 can be interchanged, but AGA and late ECS are more complex. And yes davideo, the 4000D and T use differnet ones because the 4000t has SCSI AND IDE which require specific bootloader instructions. The 4000 and 3000 use different Chipsets and one has SCSI and the other IDE. Other than that, I can't tell ya
 
Re: Kickstart 3.1 versions -- What's the difference

You just forgot the PCMCIA on A1200 (cardresource.device). The rest is right.
 
Re: Kickstart 3.1 versions -- What's the difference

That makes sense. So, what happens if you use the wrong ROMs? Will you just lose some of the features, or will they not boot at all? (Assuming they will even fit!)
 
Re: Kickstart 3.1 versions -- What's the difference

@Andy

Lets Talk Amiga Roms

Amiga Roms, are pretty much like Firmware, however as opposed to just storing memory ranges (like that in a PC) they actualy store small programs that are run on boot.

Most notibly the firswt thing to run on boot is Exec this is a preemptive multitasking kernel and everything else runs on top of that. Kickroms also include an abstraction of the Amiga's unique hardware, a disk operating system called AmigaDOS, a windowing system API called Intuition which provides a *base* graphical user interface (windows) that is called by Workbench.

Amiga A500, A600 and A2000: Rom unifictation

Now before 3.0 and 3.1 there were many differing versions of 2.x, some had native IDE support, some only partial and some none at all. Ssome 2x ROMS had PCMCIA mapping and some didn't (and this even includes some that were shipped with the A600!)

Taking the A600 aside for the moment, the A500 and A2000 are almost identical in design, with the exception of a zorro II bus, the chipset and electrical layout is in fact identical. This is one of the reasons why Jay Minor went on record (and against commodore) by saying "The A2000 does not represet a significant enough of an upgrade to invest in" not that it stopped anyone lol. Within 8 Years A2000's equipped with 040's became the work horse for Raytracing / rendering and Video Toasting.

Now lets get back the A600

The A600 unlike the A500/A2000 has a PCMCIA port, this is a mapped area of memory space that can be ignored and over written, so in the ROM unification of the A500,A600 and A2000 under the official Kickstart 3.1 there exists memory mapping for the PCMCIA port even though the A500 and A2000 dont have this circuitry.

Getting to grips with the A1200 / A3000 and A4000

Surprising as it might sound None of these machines share a direct architecture, sure the A4000 uses AGA as does the A1200, but after that they have very little in common. The A1200 architectually speaking is A lot like an A2000 with AGA and a base 020EC processor.

The A1200 has essentially a Zorro 2 bus, however although its a 32bit machine it only has a 24bit encoder/decoder of memory addressing. This limmits the memory map drastically comparied to a full core 020 or higher.

Whoms the close relative?
The A3000, although uses an ECS chipset is a full 32bit design, having Zorro 3 and DMA transfers (very important btw), in a lot of ways the A3000 is more like an A4000 both have Zorro 3, DMA and 32bit wide architecture from the offest, and thats why an A3000 is more like an A4000 compared to the A1200 (irrespective of AGA chipset).

A little bit about A3000 and Amber
The A3000 also has an Amber Circuit that was an optional card on the A2000, implemented on the A3000 and then removed and placed an an optional component on the A4000 video port. Due to the extra Bitfiled of AGA it was cost effective from Commodores standpoint to allow the user to *upgrade* to use an industry standard monitor was quite a cheek at the time compared to the price of an A4000!!! (there method was to bundle multisync monitors)

So why two chips of ROM instead of 1?

As you have touched on, its all a matter of bits and bytes =D, the A1200/A3000 and A4000 are infact 32bit machines and as such process their data in 32 bits wide, as such they access (address and decode) both roms (16bit each) simultaneously for a (32bit wide data)

It can be a trick to get your head round the 24bit nature of the A1200 ec020, but this 24bit limmitation is its amount of memory to address not how it addresses it.

there.... that should help.
 
Re: Kickstart 3.1 versions -- What's the difference

Also both SCSI.device and cardresource.device found on 40.63 (3.1 for A500/600/2000) don't stay resident if the correspondent hardware is not found (no Gayle in A500/2000).

For those who doubt it, simply run Sysinfo or Sysspeed (MUI is required), they show the resident devices on the Amiga. My 3.1 A500 + SCSI HD don't have SCSI & cardresource. But the better is making a custom kickstart for those machines stripping out unnecessary things and using the room for more necessary things, like a new exec (Piru's fastexec comes to my mind) if you have some FAST RAM. :wink:

Do someone imagine a "poor" 68000 machine using a heavily patched system with no RAM loss? :D
 
Re: Kickstart 3.1 versions -- What's the difference

Custom Kickstart looks a fascinating idea. I already found this: http://www.doobreynet.co.uk/flash.html which I might like to have a play with.

Then all I'd need is a way to get the images back in to the Amiga. I wonder if the ChipLab at work can program suitable EEPROMs. :)
 
Re: Kickstart 3.1 versions -- What's the difference

Flash kickstart rocks big time.

It is one of my projects I dropped out when I saw Redskull's schematics. I wasn't keen to re-invent the wheel. The project is simple enough to be made for anyone who knows a bit about copper circuit routing.

[EDIT]kick link to flash projects on Aminet:
Kickflash for A500/600/2000 :mrgreen:
 
Re: Kickstart 3.1 versions -- What's the difference

AndyLandy said:
That makes sense. So, what happens if you use the wrong ROMs? Will you just lose some of the features, or will they not boot at all? (Assuming they will even fit!)
The reason I ask is that the cheapest I can find an A4000D kickstart is about £37, but I can get the A4000T one much cheaper. I'm not sure I understand why the prices are so disparate.
So, firstly if anyone has some KS3.1 ROMs for A4000D that they'd like to sell for something less-obscene, I'm interested in buying.
Alternatively, what are the options for flashing my own ROMs? I've got access to an EEPROM programmer and can get suitable chips quite cheap, but I believe the ROMs are still copyrighted? Can I buy an image and flash that?
Finally, can I use 4000T ROMs in a 4000D board? I'm assuming not.
 
Re: Kickstart 3.1 versions -- What's the difference

AndyLandy said:
That makes sense. So, what happens if you use the wrong ROMs? Will you just lose some of the features, or will they not boot at all? (Assuming they will even fit!)

At best mr. Guru will visit you very soon on the boot process. Pending on what ROM you use, of course. A4000T version have two SCSI.device (one for the IDE, one for the built-in SCSI). Of course the desktop version don't have the SCSI controller at all. This may pose a problem, maybe not. Oh, they will fit.

The reason I ask is that the cheapest I can find an A4000D kickstart is about £37, but I can get the A4000T one much cheaper. I'm not sure I understand why the prices are so disparate.
So, firstly if anyone has some KS3.1 ROMs for A4000D that they'd like to sell for something less-obscene, I'm interested in buying.

I only have a pair of self-made 3.9 for mine long-gone A4kD... Yes, I have original 3.9 CD and 3.1 ROM on mine A1200 and the wistful A4000D had those, too.:sigh:

Not for sale for obvious reasons.:pirate:

Alternatively, what are the options for flashing my own ROMs? I've got access to an EEPROM programmer and can get suitable chips quite cheap, but I believe the ROMs are still copyrighted? Can I buy an image and flash that?
Finally, can I use 4000T ROMs in a 4000D board? I'm assuming not.

Using a kickflash from Individual Computers, a Deneb, or even a pair of the Aminet's A500 flash project will give you the ability to use the ROM version you wish, not only one or two!
 
Re: Kickstart 3.1 versions -- What's the difference

rkauer said:
<snip>

I only have a pair of self-made 3.9 for mine long-gone A4kD... Yes, I have original 3.9 CD and 3.1 ROM on mine A1200 and the wistful A4000D had those, too.:sigh:

Not for sale for obvious reasons.:pirate: <snip>

So get `em backed up. :pirate:

Har har,

Kin
 
Re: Kickstart 3.1 versions -- What's the difference

-But, but, this is a backup, officer!

-Yeah, right. Save that for the jury...

:banned:
 
Re: Kickstart 3.1 versions -- What's the difference

I know m8y. A right can of worms tbh. (n)

Kin
 
Back
Top Bottom