Stuff thats not completely compatible

[Tenacious]

It has happened several times that I've spent my allowance on a much anticipated upgrade only to get it home and find that it's incompatible with my existing system.  It seems that often the manufacturer was aware of the shortcoming but didn't warn of the problem in advance.  I don't want to start a flame war, but rather, a simple listing of those things never listed in the small print.  It would help people who are still collecting new, and old, stuff.

My example: the A570 (boot from a CD like a CDTV) is a cool upgrade for an unexpanded A500, but it can't take acceleration.  It works for a month or so and then gets flakey and finally refuses to boot.  I tryed it with AdSpeed and Supra's 28Mhz accelerator with the same result.  The A570 is compatible with Supra's 500RX ram expansion and Amitrix hard drive expansion.

[lempkee]

phase 5 a1200 ppc cards aint working with mediators or grexx's unless you update the onboard rom (flash it).

the update is small and easy, anyone can do it.

[darksun9210]

yeah, like 64/128Mb 72 pin simms in a cyberstormPPC! grrrr. not fair.
for peace of mind, get 32Mb FPM simms not the edo version, or it'll only recognise the first bank of 16Mb per simm. something to do with PC hardware people getting lazy and not adering to the standard as EDO was really a stop gap so they could make cheaper memory controllers.

but they work in a blizzard PPC, upto 128Mb per simm! whats that about? can the cyberstorm be flashed to take 128Mb simms? 512Mb of ram!

oh well....

[Kronos]

@darksun

No chance  :-x  :-x

Atleast not with a simple reflash.

Maybe it would be possible to do something with a soldering iron .....

Speaking of that, I do remeber a patch for the 2630 that replaced the 1mbit ZIP-chips with
4mbit-ones, allowing 16mb onboard.

Anybody with a link to that ??

[rhino]

AIUI the memory limit on the Cyberstorm (and all other accelerators using that slot) is due to the design of the A3000/4000 CPU slot which can only address 128Mb.

I suppose at the time the A3000 was being designed (the first Amiga to have that slot design) 128Mb seemed like a huge amount and would have cost several thousand dollars. As a reference I remember when I got my A4000 in '94 4Mb SIMMs were over 200UKP each:)

Robert

[Kronos]

@rhino

Not correct (atleast not 100%) ...

More RAM on the slot is possible, just like you can have more than 16mb in the
A2000-MMU(CPU) slot, which only has 24 address lines.

There even was (probraly never released) a RAM-card for the A4000 that would
go between mobo and CPU-card.

[rhino]

@Kronos

My hardware knowledge is very limited but I'm not aware of any CPU slot accelerator that could accept more than 128Mb (of course that doesn't mean it's not possible).

I thought that in the A3000/4000 (unlike the A2000 which is a 16bit machine) the rest of the address space was already allocated for Zorro III cards.

If anyone is interested here are some documents from Dave Haynie on the A3000 design:

An overview which mentions the address limit.
The CPU slot specification.

Robert

[darksun9210]

wait wait waaaaait a cotten picken minute here.

i seem to remember something along those lines.
White knight Technology (anyone remember those guys?) used to advertise (amongst otherthings) an Excaliber board. it said something like
"use your existing processor! add an extra 128Mb of ram!"
leading people to belive it was a card that went betweeen the accelerator and the mainboard. as that was the only way it would seem to fit into the advertising....
but what they MENT was, uses the CPU off your accelerator / A3640 and gives you capacity for extra 128Mb ram... basicly like a warp engine without the CPU or scsi interface. major disapointment. i only found out about 8 months ago.

oh and yeah, i remember the 4Mb for £120 UK pounds. so at the time of design, 128Mb was a nutty amount, but the zorro3 standard allows for 256Mb of addressable space per slot. as far as i can tell in the design documents mentioned above, i can only see about 1.3Gb required for the mainboard. so these bus boards with 7 slots and one CPU slot if filled to capacity  would give ~1.9Gb. total 3.2Gb out of 4Gb.

so really it is do-able. but i think you are right with regard to the CPU slot addressing. 128Mb Was a crazy amount about hmm 10 years ago. so why more? this is the problem here, we are looking at a 10 year old design i suppose.... would have been nice tho... like 8Mb chip ram  ;-)

[Kronos]

Mmmmmh ....

But when it is really limited to 128mb, where do the 8mb of the CV-PPC map to ?

Or the 16/32mb of a Voodoo in a GRex ?

Hell, where the CS-PPC/MK3's whole PCI-address-space

[darksun9210]

dammit! i never thought ot that!  :-D

1.76Gb of addressing and it goes where?

D'oh!

[rhino]

@Kronos

I see what you mean, I hadn't considered the CVision PPC and GRex.

I think its safe to say that any additional memory installed on a CPU slot accelerator could not be contiguous with the first 128Mb block, even if it is possible to make a card which supports it.

Presumably the CSPPC expansions must map either into the Zorro III space (if that's possible) or above 2Gb. I don't understand this enough to make any further comments.

Where's a hardware engineer when you need one

Robert

[Kronos]

@rhino

probraly abaove the 2gb (from what I've heard), but that isn't really a prob.

PCI-RAM-card anyone :-D

[Tenacious]

This is a great discussion.  I wish I had the ability to break this out into the seperate thread it deserves. (Grin)  I was fishing for a comprehensive list of incompatibilities that are not obvious, hardware combinations that should work but don't, like trying to accelerate a system that already has an A570.

[DoomMaster]

All you have to do is just get rid of that toy Amiga 500 and get yourself a real Amiga, like the Amiga 2000, 3000, or 4000.  The Amiga 500, 600 and 1200 are toy Amigas for folks that can not afford the professional series.  Since you already have an Amiga 500, keep it for spare parts to an Amiga 2000HD.  You can pick up a nice Amiga 2000HD from eBay for less then $100.00 and it is a much nicer machine then the Amiga 500 toy computer.  In fact, the Amiga 2000 is the Flagship of all Amiga computers because more expansion cards have been produced for it then any other Amiga.  The Amiga 3000 and 4000 are very nice computers, but they are not as expandable as the Amiga 2000 professional computer.  In fact, I am now running Amiga OS 4.0 Beta on my own Amiga 2000HD.  I think that OS 3.9 is better then the new OS 4.0.  It is my professional opinion that the new AmigaOne OS 4.0 SUCKS!  OS 3.9 is much better and is the Commodore Amiga's last true operating system.  OS 4.0 is NOT a true Amiga operating system and is getting closer to being like a PC, so I personally will not buy OS 4.0.  Afterall, I already have a Pentium 4 PC, I do not need another PC compatible (OS 4.0).  Anyway, get yourself a nice Amiga 2000HD and I know that you will just love it.   :-D

[itix]

But when it is really limited to 128mb, where do the 8mb of the CV-PPC map to ?

On CPU-card itself you dont have such limitations... CPU itself can always address up to 4GB. In this case 8MB of the CVPPC is 'unreachable' for the rest of system.

(I think.. never cared that much of HW details...)