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AuthorTopic: Anyone have a source for ram chips for the A2058?  (Read 782 times)

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Offline Malakie

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Anyone have a source for ram chips for the A2058?
« on: November 30, 2021, 06:00:09 AM »
Anyone have a source for ram chips for the A2058?   I have a couple cards I would like to fill up.. Thankfully all my A2091 cards are fully populated but both my A2058 cards are not and need 6 meg each to fill.
« Last Edit: November 30, 2021, 06:00:44 AM by Malakie »
Take it light...... :-D

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Offline Pat the Cat

Re: Anyone have a source for ram chips for the A2058?
« Reply #1 on: December 01, 2021, 10:57:01 AM »
Might be worth sniffing out local Hackerspace / Makerspace?

They get stuff donated, also members can have hoards of retro gear for "projects" (unfulfilled dreams).

You might have an issue with RAM on the A2091 - you can't set an A2058 to have 6MB... and you can only have 8MB total fast RAM? On a 68000 Amiga?

And you do want some RAM on the A2091 to let it use DMA.
« Last Edit: December 01, 2021, 11:20:06 AM by Pat the Cat »
"To recurse is human. To iterate, divine."

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Offline psxphill

Re: Anyone have a source for ram chips for the A2058?
« Reply #2 on: December 01, 2021, 08:03:32 PM »
And you do want some RAM on the A2091 to let it use DMA.

I didn't think the ram had to be on the card itself, you just need some zorro 2 fast ram somewhere.
 

Offline Malakie

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Re: Anyone have a source for ram chips for the A2058?
« Reply #3 on: December 01, 2021, 09:39:17 PM »
Might be worth sniffing out local Hackerspace / Makerspace?

They get stuff donated, also members can have hoards of retro gear for "projects" (unfulfilled dreams).

You might have an issue with RAM on the A2091 - you can't set an A2058 to have 6MB... and you can only have 8MB total fast RAM? On a 68000 Amiga?

And you do want some RAM on the A2091 to let it use DMA.


You can have much more than 8 meg on an Amiga, even a older model.  I have one machine with 128 meg of ram.  One machine with 24 meg of ram, both A2000 systems.  One with an accelerator, the other stock 68000.     And the A2091's are already populated with 2 meg.  I don't need ram for those, only for the A2058's of which I need an additional 6 meg for each card.  They already come with 2 meg stock built in and are a maximum of 8 meg once filled.


So I need 6 meg of chips, x 2, for both A2058's I have to fill now, which will bring each of them to their max of 8 meg of ram.



Take it light...... :-D

Malakie
 

Offline Matt_H

Re: Anyone have a source for ram chips for the A2058?
« Reply #4 on: December 01, 2021, 09:48:35 PM »
Might be worth sniffing out local Hackerspace / Makerspace?

They get stuff donated, also members can have hoards of retro gear for "projects" (unfulfilled dreams).

You might have an issue with RAM on the A2091 - you can't set an A2058 to have 6MB... and you can only have 8MB total fast RAM? On a 68000 Amiga?

And you do want some RAM on the A2091 to let it use DMA.


You can have much more than 8 meg on an Amiga, even a older model.  I have one machine with 128 meg of ram.  One machine with 24 meg of ram, both A2000 systems.  One with an accelerator, the other stock 68000.     And the A2091's are already populated with 2 meg.  I don't need ram for those, only for the A2058's of which I need an additional 6 meg for each card.  They already come with 2 meg stock built in and are a maximum of 8 meg once filled.


So I need 6 meg of chips, x 2, for both A2058's I have to fill now, which will bring each of them to their max of 8 meg of ram.

The system as a whole can have plenty more than 8MB, but the Zorro II bus will max out at 8MB. 8MB on the 2058 plus 2MB on the 2091 will cause some issues.
 

Offline Malakie

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Re: Anyone have a source for ram chips for the A2058?
« Reply #5 on: December 01, 2021, 10:12:04 PM »
Might be worth sniffing out local Hackerspace / Makerspace?

They get stuff donated, also members can have hoards of retro gear for "projects" (unfulfilled dreams).

You might have an issue with RAM on the A2091 - you can't set an A2058 to have 6MB... and you can only have 8MB total fast RAM? On a 68000 Amiga?

And you do want some RAM on the A2091 to let it use DMA.


You can have much more than 8 meg on an Amiga, even a older model.  I have one machine with 128 meg of ram.  One machine with 24 meg of ram, both A2000 systems.  One with an accelerator, the other stock 68000.     And the A2091's are already populated with 2 meg.  I don't need ram for those, only for the A2058's of which I need an additional 6 meg for each card.  They already come with 2 meg stock built in and are a maximum of 8 meg once filled.


So I need 6 meg of chips, x 2, for both A2058's I have to fill now, which will bring each of them to their max of 8 meg of ram.

The system as a whole can have plenty more than 8MB, but the Zorro II bus will max out at 8MB. 8MB on the 2058 plus 2MB on the 2091 will cause some issues.


It should not cause any issues if the boards are mapped correctly for memory.  As long as they each have their own unique address, you should  and can use multiple boards and more ram as fast ram.  Not only was this something we did back in the day, but I have a system doing it right now as I mentioned.  No issues what so ever.   I can populate all that ram with a problem.  I AM using only official stock boards in this machine, all z2 and no 3rd party stuff. There IS a caveat to this however..  You need a 4.6 (if I am remembering right from that far back) or better rev motherboard at the least.   It might be a Rev 5 series, I will have to dig up some of my tech data from back then to be sure.  Rev 6 boards should work fine and the B2000 boards, which I have one of those as well, are going to be a problem because they were never sold.  The B2000 boards we gave to dealers ONLY as SHOW units because they have an inherent flaw in the design that has to do with DMA and zorro issues.  So they are going to be a problem with a few things for anyone trying to use those for anything more than a standard basic Amiga system.

Another way to get around that, is z3 cards or CPU slot cards or if I remember right, there are even a couple video card slot ram cards that also work.. not sure on this latter one though but I thought I remembered seeing it available somewhere.   My other machine has 128 meg ram but I am using the CPU slot for that.  The stock machine, I have the 24 meg in because I am using 4096 block CF cards for the drives which eat ram and validation is an issue if you don't have enough of it, as you know.

BTW, did you note I found the other problem while troubleshooting.  Bad 7.0 rom burns for the two sets I bought.. Replacements are on the way so for now using my official set in one and the 8.0 set in the main machine I use.



Take it light...... :-D

Malakie
 

Offline Matt_H

Re: Anyone have a source for ram chips for the A2058?
« Reply #6 on: December 01, 2021, 11:03:26 PM »
It should not cause any issues if the boards are mapped correctly for memory.  As long as they each have their own unique address, you should  and can use multiple boards and more ram as fast ram.  Not only was this something we did back in the day, but I have a system doing it right now as I mentioned.  No issues what so ever.   I can populate all that ram with a problem.  I AM using only official stock boards in this machine, all z2 and no 3rd party stuff. There IS a caveat to this however..  You need a 4.6 (if I am remembering right from that far back) or better rev motherboard at the least.   It might be a Rev 5 series, I will have to dig up some of my tech data from back then to be sure.  Rev 6 boards should work fine and the B2000 boards, which I have one of those as well, are going to be a problem because they were never sold.  The B2000 boards we gave to dealers ONLY as SHOW units because they have an inherent flaw in the design that has to do with DMA and zorro issues.  So they are going to be a problem with a few things for anyone trying to use those for anything more than a standard basic Amiga system.

Pardon my skepticism, but if it's true that you have 24MB on the Zorro II bus running stable with no sneaky/subtle issues, then this is new knowledge that I think is not known in the community. Can you share a screengrab of your output from ShowConfig? That will give some basic info on the addresses involved. And it would be great if you could find and scan/share some vintage technical bulletins relating to this. I'm sure many would be interested.

I think the B2000 Zorro/DMA issues you mention might refer to rev 3.8 or 3.9? Have a look at Dave Haynie's notes about revisions.

Quote
Another way to get around that, is z3 cards or CPU slot cards or if I remember right, there are even a couple video card slot ram cards that also work.. not sure on this latter one though but I thought I remembered seeing it available somewhere.   My other machine has 128 meg ram but I am using the CPU slot for that.  The stock machine, I have the 24 meg in because I am using 4096 block CF cards for the drives which eat ram and validation is an issue if you don't have enough of it, as you know.

Not just another way, I thought Zorro III and the CPU bus were the only way to get >8MB until you mentioned your 2058 magic.

Quote
BTW, did you note I found the other problem while troubleshooting.  Bad 7.0 rom burns for the two sets I bought.. Replacements are on the way so for now using my official set in one and the 8.0 set in the main machine I use.
Yup, good catch. I think I mentioned there that rev 8 ROMs for the 2091 are also not generally known, so you may want to get those dumped/shared, too.
« Last Edit: December 01, 2021, 11:03:57 PM by Matt_H »
 

Offline Malakie

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Re: Anyone have a source for ram chips for the A2058?
« Reply #7 on: December 02, 2021, 01:03:56 AM »
It should not cause any issues if the boards are mapped correctly for memory.  As long as they each have their own unique address, you should  and can use multiple boards and more ram as fast ram.  Not only was this something we did back in the day, but I have a system doing it right now as I mentioned.  No issues what so ever.   I can populate all that ram with a problem.  I AM using only official stock boards in this machine, all z2 and no 3rd party stuff. There IS a caveat to this however..  You need a 4.6 (if I am remembering right from that far back) or better rev motherboard at the least.   It might be a Rev 5 series, I will have to dig up some of my tech data from back then to be sure.  Rev 6 boards should work fine and the B2000 boards, which I have one of those as well, are going to be a problem because they were never sold.  The B2000 boards we gave to dealers ONLY as SHOW units because they have an inherent flaw in the design that has to do with DMA and zorro issues.  So they are going to be a problem with a few things for anyone trying to use those for anything more than a standard basic Amiga system.

Pardon my skepticism, but if it's true that you have 24MB on the Zorro II bus running stable with no sneaky/subtle issues, then this is new knowledge that I think is not known in the community. Can you share a screengrab of your output from ShowConfig? That will give some basic info on the addresses involved. And it would be great if you could find and scan/share some vintage technical bulletins relating to this. I'm sure many would be interested.

I think the B2000 Zorro/DMA issues you mention might refer to rev 3.8 or 3.9? Have a look at Dave Haynie's notes about revisions.

Quote
Another way to get around that, is z3 cards or CPU slot cards or if I remember right, there are even a couple video card slot ram cards that also work.. not sure on this latter one though but I thought I remembered seeing it available somewhere.   My other machine has 128 meg ram but I am using the CPU slot for that.  The stock machine, I have the 24 meg in because I am using 4096 block CF cards for the drives which eat ram and validation is an issue if you don't have enough of it, as you know.

Not just another way, I thought Zorro III and the CPU bus were the only way to get >8MB until you mentioned your 2058 magic.

Quote
BTW, did you note I found the other problem while troubleshooting.  Bad 7.0 rom burns for the two sets I bought.. Replacements are on the way so for now using my official set in one and the 8.0 set in the main machine I use.
Yup, good catch. I think I mentioned there that rev 8 ROMs for the 2091 are also not generally known, so you may want to get those dumped/shared, too.


Actually the B2000 units are B2000CR rev 4.0 boards.  These were dealer sent only and never sold.  I am sure a few dealers, especially after Commodore folded, sold some of them but I bet they never told anyone they were not to be sold due to technical design flaws.


As for the ram amount, what do you mean by sneaky/subtle problems?   I will have to figure out the best way to dump a screengrab with what I have here now.  Each card, should have a specific memory address that it starts and ends at.  If they overlap, then yes you would get some major problems the more memory you use.  Keep in mind I am trying to remember specific info that is now 35 years old so it may take something to bring a memory back up from back then for some of the answers I give.  While I ain't old, it is still a long time to try and remember some of the deeper things for configuration and such until something jobs my memory about it or I can find the technical data, which will be a chore in itself because I put everything on digital eventually.



Take it light...... :-D

Malakie
 

Offline Pat the Cat

Re: Anyone have a source for ram chips for the A2058?
« Reply #8 on: December 02, 2021, 03:27:36 AM »
I reckon the beans on this is if you can map the full 8MB to a place other than where the A2091 RAM goes.

With software that is. It did come with software but I've never played with an A2058.

5adly a link to an Amiga memory map is currently missing. What follows seems a little lacking.

http://oscomp.hu/depot/amiga_memory_map.html

I think you do have an extra 1.5MB space in the memory map, C00000 slow RAM, but you only have 16MB total space on a 24 bit address bus.
"To recurse is human. To iterate, divine."

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Offline Matt_H

Re: Anyone have a source for ram chips for the A2058?
« Reply #9 on: December 02, 2021, 03:33:39 AM »
As for the ram amount, what do you mean by sneaky/subtle problems?
Meaning the system might appear to function normally and even report 24MB, but if you fill up RAM Disk: with >8MB of data you start getting corruption/crashes. The addresses above 8MB quickly start conflicting with other resources.

Quote
I will have to figure out the best way to dump a screengrab with what I have here now.
A simple photo of the monitor/screen will do. :)

Quote
Each card, should have a specific memory address that it starts and ends at.  If they overlap, then yes you would get some major problems the more memory you use.  Keep in mind I am trying to remember specific info that is now 35 years old so it may take something to bring a memory back up from back then for some of the answers I give.  While I ain't old, it is still a long time to try and remember some of the deeper things for configuration and such until something jobs my memory about it or I can find the technical data, which will be a chore in itself because I put everything on digital eventually.
The nature of human memory is to be fallible. It's okay to misremember things. ;) I'm just genuinely curious if what you're describing is possible.
 

Offline Pat the Cat

Re: Anyone have a source for ram chips for the A2058?
« Reply #10 on: December 02, 2021, 04:00:22 AM »
I don't see how you could do it with a 68000.

You might be able to do it with a co-processor card, but it's only going to be 16 bit access speed. Rather than RAM on the coprocesser card itself accessing 32 data bits at one gulp. Possibly more (Burst? I thought you need very special RAM for that., 68030 (up?).
"To recurse is human. To iterate, divine."

A1200, Vanilla, Surf Squirrel, SD Card, KS 3.0/3.z, PCMCIA dev
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