Adding Ram to A500

[toca180]

Hi

Ive got an A500 with A590 (2mb ram), mtec 68020i (with 4mb ram and fpu), Cortex 8 mb ram expandtion (only has 4mb fitted) and a Marpet MP502A 512k trapdoor expanstion. The cortex and A590 have auto configed fine but the other two haven't. How do I add the other two so I can use them? Please explain it as easily as possible. :-)

Thanks
Robert

[patrik]

The reason the MTec 68020i hasnt configured its memory is probably because it wants to configure it in the 8MB Zorro2 space which is already filled with 6MB (A590 = 2MB, Cortex = 4MB). Populate the Cortex with only 2MB ram or remove it completely, then everything should work fine. To get any speed out of the MTec, you need it to configure its own fastram as it is 32-bit.

The trapdoor-expansion should however work. Are you sure it is not just poping up as 512kB extra chipmem on your A500? Also make sure the Marpets disable-jumper isnt set.


/Patrik

[toca180]

Thanks, for the fast reply.

If I close the auto config jumper on the mtec it on longer boots from the 590, I just get the 3.1 ks screen. If I load workbench from floppy the ram on the mtec is there and the ram from the 590, as there is 6mb of other, but the hard drive partitions are not there. I also get hard drive (2gb scsi) activity before the ks screen. :-?

With the only jumper on the Marpet open it will boot but with no extra ram

All this is without the cortex connected.

Thanks
Robert

[patrik]

@toca180:

Hmm.. the A590 is a dma scsi controller, which means that it will transfer the data by itself to ram. Maybe the MTec 68020i is one of those ugly hacks which doesn't allow dma transfers to its own ram (only the 68020 on it can access the it) and thus the A590 fails when it is told to transfer to the MTec ram (when enabled, it will get the highest priority) which it then will fail.

I cant find any notes about this on either amiga.resource.cx or www.amiga-hardware.com. The only thing it says is that it is incompatible with the GVP Impact series of harddrives which is a common dma scsi controller which atleast suggest that the case is like I reasoned above. Do you have a manual for it and if so - does it say anything about this?

If this is the case, such cards should mark their memory as non MEMF_24BITDMA to make the driver for the harddrive-controller gracefully avoid it. Though it might not be implemented in the version of the drivers you have or not at all. I also think that you can play around with the transfermask for your partitions to force it to dma to only chip-ram for example. Does anyone else have any good advice on this perhaps?

(edit):

I noticed I was a sloppy reader. On www.amiga-hardware.com it is mentioned that there had been problems reported using this card with a A2091 which is the same hardware as the A590, but as Zorro2 card instead.


/Patrik

[toca180]

Unfortunatly I don't have the manual. I got it from ebay and it is just the board.  :-(

Is there anyway that I can manually add the ram, for both the mtec and marpet? If so will this still cause the same problems?

Thanks

Robert

[patrik]

@toca180:

The MTec memory should be possible to add with something like AddMem. The marpet though is a 512chip/slowfast expansion and is added by the system if it finds it. Are you sure it doesnt add any chipmem to your system?

Regarding the issues with the A590 - you could always try to upgrade to the latest drivers (you will need to program a eprom) and see if it helps. Ask around the forum for the rom-image for the latest drivers. Btw, what version do you have now? (do a "version full scsi.device" in a cli).


/Patrik

[toca180]

When I type that in I get:

scsi.device 40.5 (13/09/93)

I assume I have to add a line to my user-startup or Start-Sequence, which one? If I put AddMem into the C draw would this be the line I need to add:

AddMem START 40000 TO 7FFFFF [PRI value (what is it? What should I put?)] [NAME mtec (would this be ok?)]

I start as 400000 as show config tells me that the 590 is added at 200000 to 3FFFFF.

As for the Marpet, I think it might have just been a bad contact. As I just reseated the ram and it now works. (Guess I should ahve done that first.  me :destroy: )

Thanks
Robert

[patrik]

Does anyone know what A590 driver rom version 40.5 of scsi.device corresponds to?

Priority is a number which is used by the system to know which memory to prefer. If say you set it to 5 and the other memory has 0, it will prefer the former.


/Patrik

[toca180]

When I type into a cli "AddMem START 400000 TO 7FFFFF" it makes my amiga freeze and I have to reset it.

Why would this be? What am I doing wrong?

Thanks
Robert

[patrik]

@toca180:

Wrong address maybe? Let the MTec autoconfigure and run the ShowConfig utility which should be on the Extras disk to get the 100% correct address. If that address is the same or doesn't work, maybe it is so that when you don't let the card autoconfigure the memory it just doesn't setup the memory at any address.


/Patrik

[adolescent]

As Patrik mentioned, the Mtec 020i doesn't work with DMA HD controllers.  There is some sort of a patch/workaround on the driver disk for the A590 and A2091.  (When I had mine I used a non-DMA Dataflyer SCSI sidecar, but it didn't work with my A570 either (nor did the patch help, since it would lock up at before boot.)

[Zac67]

The easiest way to work around the non-DMA issue is to use the buffer address mask (in HDPrep) to make sure the buffers are allocated within DMA memory. E.g. if the first 4 megs support DMA and 4+ meg not, you'd use a mask of 0x3ffffc. You'll need to find out where each expansion's memory is located at first.

Obviously it makes sense to fully use the Mtec's memory and reduce the 16 bit RAM to the needed limit (assuming the Mtec mem configures below the 'magic' 16 meg, so that it 'collides' with the Zorro II mem expansion).

[Merc]

I had a similar problem with my A500+A590 when I added an Mtec 68020 card.  What I ended up doing to get the best performance was turning off the autoconfig on the A590 (or automount or autoboot, I forget which).  The problem was that with the 020 enabled, and autoboot turned on, the A590 didn't even initialize, and the machine would just hang on a white screen.

Once I turned off automount/autoboot or autoconfig (I think it was the 1st jumper on the back of the A590), I made a boot floppy that mounted the drive manually, and did the necessary assigns to start the system from HD.  It was a bit of a nasty hack, but it did work.  I think I also had to change the maxtransfer and/or dma mask on the A590 to get it to run relatively stably, and even then it did occasionally hang during transfers to/from disk for some reason

Some kind person somewhere overseas actually burned some new EPROMS for the 590 for me, which upgraded the 590 to the 6.6 SCSI firmware (I think, it's been 10 years now), but sadly this didn't help.

I ended up getting a Trumpcard IDE controller shortly thereafter though, which didn't have any of these problems.  It was a lot faster than that A590 too.

Hope this helps you a bit, if you need a little more detail or info, just let me know!

[Zac67]

toca180 wrote:
scsi.device 40.5 (13/09/93)

Does look like the very latest - I'd be surprised if anything happened to the ROMs after 09/93.

AddMem START 40000 TO 7FFFFF [PRI value (what is it? What should I put?)] [NAME mtec (would this be ok?)]

There must be five '0's to the 4 - otherwise you're adding memory your 500's already using... :crazy:
PRI should be +10 or +20 to have 32 bit RAM allocated first (chip is 0, 16 bit fast is +5).

[Michael_D]

Hi,

try http://www.amiga-hardware.com/drivers/A500_Accelerators/mtec020and030.dms
It includes two AddMem-tools. "Add32Bit" and "Add32Bit_special".
They add the memory if it's not set to autoconfig and shows
the memory adresses and size.
The "special"-version makes it reset proof.
AFAIR there's a tool on the disc which can change the adressmask of the partitions to not use DMA to 32Bit.