I want more than 2mb Fast RAM on my A1000...how?

[Amiga_Nut]

Is there a technical reason why all A1000 zorro side expansion slot memory boards are 2mb max for the A1000? If I slot in an A500 8mb unit will it work or will the A1000 only see the first 2mb for some technical reason despite the Zorro 1 slot being identical?  If I use TWO 2mb ram boards and one has a pass through and connect them both together what happens? Fire? Explosion? Space-Time continuum folds in on itself and we instantaneously get transported back to 1960s?

[JimS]

There's no reason why an A1000 can't address more than 2MB of fast ram. I think most of the slap-on-the-side expansions for the 1000 stopped at 2MB was just because of the expense. If the autoconfig passthru on those 2MB boards is correct, you should be able to connect them both without disrupting subspace. It may not work reliably though, that buss was kinda noisy. The A500 unit should work fine - even if you have to put it on backwards. ;-) I used a Phoenix expansion box which held 2 regular Zorro cards on my 1000. I ran a CBM 2058 RAM card half filled (4MB) and a Trumpcard SCSI controller just fine.

[TheGoose]

Is there a technical reason why all A1000 zorro side expansion slot memory boards are 2mb max for the A1000? If I slot in an A500 8mb unit will it work or will the A1000 only see the first 2mb for some technical reason despite the Zorro 1 slot being identical?  If I use TWO 2mb ram boards and one has a pass through and connect them both together what happens? Fire? Explosion? Space-Time continuum folds in on itself and we instantaneously get transported back to 1960s?

"Space-Time continuum folds in on itself and we instantaneously get transported back to 1960s" - And you might turn into John Denver.

Actually I think (correct me anyone):

1. There is a 8 MB limit on the A1000 ?
2. You can chain several sidecar expansions together, totally safe, that's why many of them have a pass-through.

Now, some combinations might give you trouble, but most that were built with kickstart 1.3 (with autoconfig support) will all work nicely.

[Amiga_Nut]

OK cheers, I just stumbled upon an auction for another side car expansion (just waiting for the seller to confirm total RAM present on it) and that would give me 4 1/2 mb rather than 2.5mb I have now (only 2mb with KS2.0 softloaded)

I know 8mb is the theoretical limit due to the A500/2000 being limited to 8mb 16bit FAST RAM, wasn't sure why the A1000 never had a 2mb side expansion unit.

[gertsy]

OK cheers, I just stumbled upon an auction for another side car expansion (just waiting for the seller to confirm total RAM present on it) and that would give me 4 1/2 mb rather than 2.5mb I have now (only 2mb with KS2.0 softloaded)

I know 8mb is the theoretical limit due to the A500/2000 being limited to 8mb 16bit FAST RAM, wasn't sure why the A1000 never had a 2mb side expansion unit.

Let us know how it goes.  Love a good piggy back.  Seen some doctored A501s that did that at a mem chip level.

[TheGoose]

@Jim "It may not work reliably though, that bus was kinda noisy."

Damn it Jim! I have never connected anything more than 2 cards... if he's going to 3, he is going into an unknown territory, the bus might not take that kind of punishment!

Let us know if you make it to the other "side" ...

:lol:

[save2600]

As others have hinted, it's theoretically possible to expand the A1000's bus beyond 2mb. BUT in reality, it's extremely difficult because of inherent noise and issues with the daughtercard. I would be shocked if you piggybacked two cards together and the second card was recognized at all because of the A1000's bus limitations. MOST all 3rd party manufacturers at the time knew that bus was funky and didn't want to deal with all the headaches that inevitably come with it.

If you do the piggyback thing, you'll want to make sure you have external power supplies (at least for the one last in line) and make sure your PAL's on the daughtercard are up to speed AND well grounded between them and the ground on the mainboard nearest the expansion bus.

Good luck indeed!  

Today, I wouldn't even bother with such a scenario. Besides, 2.5mb RAM is plenty on an A1000 with 68000 and no hard drive.

[motrucker]

There are several options to get over 2Mb. You can use two Starbaord II units - they work fine together to get up to 4.5Mb.
Also most A500 side expansion unit work fine on an A1000 - They just need to be supported (stick a book under them).
In the past I had a GVP A500+ connected to an A1000 with 8Mbs of RAM and a 120Mb hard drive (fair sized back then) and it all worked great.
I have read about a newer expansion, that adds an IDE interface and 4Mb of RAM, but I don't know who is behind that (can anyone add that info?).

[TheGoose]

Today, I wouldn't even bother with such a scenario. Besides, 2.5mb RAM is plenty on an A1000 with 68000 and no hard drive.

Save's words are pretty true. I can say, truly I have used 2 cards (ram) and they did work. And 2 / 2.5 MB should be about all you need on an old OCS machine.
Some cards / towers came with power connectors, like Save said, gave a little extra +5v to the extreme setups...

Try 2 cards briefly, see how that goes. Clean the pins on the A1000 expansion slot if you have not bothered, it can help. The underside is about impossible to reach without removing the whole MB though.

[save2600]

I have read about a newer expansion, that adds an IDE interface and 4Mb of RAM, but I don't know who is behind that (can anyone add that info?).

MrMKL's little 68k boards are awesome. Super low power and virtually no noise contention because of the design (think AdSpeed board here). He's working on an all in one board that'll have IDE, RAM and a CF slot. I know he's produced IDE and CF (no RAM) as I had one, but the thing is, it doesn't work well in the A1000 because the CF slot extends into the disk drive. And then there's the fact your A1000 Kickstarts are missing the necessary A600's IDE/SCSI.device. Best have Kickstart 3.x (okay, you *can* use 2.x, but why bother?) in ROM before thinking you can use a hard drive in it.

What I'd LOVE to see is him produce an IDE/Kickstart/RAM board. OR forego the IDE port and rig that CF card on the other side, so it doesn't interfere with the internal floppy. Actually, what would be even better than that is the CF port gets connected to a ribbon cable (too noisy?) so you could mount it somewhere so that it would be accessible to the user whenever they wanted to transfer files. Surely this can't be too much to ask?  Imagine being able to have removable mass storage like that on your A1000...  

[TheGoose]

MrMKL's little 68k boards are awesome. Super low power and virtually no noise contention because of the design (think AdSpeed board here). He's working on an all in one board that'll have IDE, RAM and a CF slot. I know he's produced IDE and CF (no RAM) as I had one, but the thing is, it doesn't work well in the A1000 because the CF slot extends into the disk drive. And then there's the fact your A1000 Kickstarts are missing the necessary A600's IDE/SCSI.device. Best have Kickstart 3.x (okay, you *can* use 2.x, but why bother?) in ROM before thinking you can use a hard drive in it.

What I'd LOVE to see is him produce an IDE/Kickstart/RAM board. OR forego the IDE port and rig that CF card on the other side, so it doesn't interfere with the internal floppy.

Who's this? where can I read more? linky....

[shaf]

When I was using the A1000 I had 3 Side Expansions installed , 2 - AX1000 2 MB RAM cards and an SA1000 SCSI Controller. Initially that gave 512KB Chip Memory and 4 MB Fast Memory. About a year later I installed the Rejuvinator Board which updated the system to 1MB Chip Memory and 4.5 MB Fast Memory.

[save2600]

Who's this? where can I read more? linky....

BTW: Goose, I sent you a PM a while ago... if you ever want to sell some of your internal A1000 stuff (such as your Multistart, AdIDE, etc.), LMK!  

Here's a linky for 'ya:

http://www.students.tut.fi/%7eleinone3/ide/i68k.html

[clusteruk]

Who said the side expansion is limited to 2mb, I have 8mb via a GVP HD8/SCSI card via a Zorro 2 adaptor, very cool.

[save2600]

Who said the side expansion is limited to 2mb, I have 8mb via a GVP HD8/SCSI card via a Zorro 2 adaptor, very cool.

Yeah, I had a setup like that for a while, but what an ugly frankenstein looking contraption it was. lol  

The kind of cards I'm talking about that (often) have problems are singular application power hungry boxes with pass-thru. Start daisy chaining those puppies up to the A1000's bus and be prepared to deal with all sorts of misc. problems.