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Old 03 January 2020, 13:18   #21
Jope
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Seems you are in luck, it won't conflict. Very puzzling that they decided to do it this way. Your system might benefit from a mergemem command being run after cRAM, however it might not work since they end at ffff7.

A very curious trapdoor card indeed. If I was you, I would get rid of this and get something that adds RAM at the 68000 socket or the AmigaBUS connector instead. What an inconvenient memory map plus the fact that it is as slow as Chip RAM.

Last edited by Jope; 03 January 2020 at 13:25.
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Old 03 January 2020, 13:34   #22
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mergemem won't work as there's at least 512kB of free address space between those blocks.

and yes, that is a strange contraption indeed.
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Old 03 January 2020, 13:48   #23
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Thanks guys - its strangeness is almost the reason I want to keep it there

What I find interesting is that it's only adding 3MB of non-ChipMem... I'm guessing it needs to configure 1MB contiguous ChipMem from the trapdoor board basically ignoring the 512KB onboard. Or do I have a bad bank of 512KB stuff?
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Old 03 January 2020, 14:58   #24
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Originally Posted by hooverphonique View Post
mergemem won't work as there's at least 512kB of free address space between those blocks.
Ah yes, it was even weirder than I thought.

Definitely the B PAL configuration and only add the enough memory to get the second 512k of chip ram + 1.5MB ranger fast would be (to me) the ideal setup for this card.
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Old 03 January 2020, 23:40   #25
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OK, so I found out why I was only getting 3.5 additional MB - one of the chips was bad in a bank. I'll grab a replacement.

Keen to give the PAL B option a go... although, what is it?!?

The PAL in there is a "PAL16L8ACN". Am I to assume I need to grab a PAL16L8BCN?
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Old 04 January 2020, 01:07   #26
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Quote:
Originally Posted by Jope View Post
Seems you are in luck, it won't conflict. Very puzzling that they decided to do it this way. Your system might benefit from a mergemem command being run after cRAM, however it might not work since they end at ffff7.

A very curious trapdoor card indeed. If I was you, I would get rid of this and get something that adds RAM at the 68000 socket or the AmigaBUS connector instead. What an inconvenient memory map plus the fact that it is as slow as Chip RAM.
It's also weird where it stuffs the extra memory. In its current config it is:

1) Only putting 511k into Ranger.
2) Putting 512k into second 512k chip ram bank (only proper behavior)
3) Putting 511k IN THE TOP BANK OF ECS CHIP MEM RANGE (meaning this thing will never work with a 2M Agnus adapter)
4) Putting the rest in 511k chunks with 513k gaps backwards from the top of Z2 memory (which yeah, means it should actually work with the A590, amazingly).

I wonder what's up with the 511k chunks. It means if you allocate anything larger than 511k it'll come out of chip memory. =P

Let us know what the memory map looks like after you replace the bad chip.
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Old 04 January 2020, 05:19   #27
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@AmigaHope - so the manual goes into it a little further... I've highlighted my config:



With my current config, I get 512KB blocks of non-contiguous FastMem up to 3.5MB (512K going to Chip).

Looks like with the PAL B chip I can get the additional 512K to make 1MB of ChipMem, 1.5MB of Autoconfig FastMem and 2MB Contiguous FastMem.

I'm tempted to get a PAL B, but I don't think I can use a 590 with it then as it overlaps the AutoConfig space...
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Old 07 January 2020, 05:19   #28
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You could try getting the PAL B and see where it maps the memory. As long as it puts the 1.5 "exec memory" in Ranger space, and as long as the rest allocates from the autoconfig space *from the top* like it does on your current setup, you should still be okay with the A590, as I believe AutoConfig allocates from the bottom.
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Old 07 January 2020, 12:54   #29
hooverphonique
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Quote:
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The PAL in there is a "PAL16L8ACN". Am I to assume I need to grab a PAL16L8BCN?
I don't think so.. A/B refers to the logic revision burned onto it by the Baseboard manufacturer, I'd assume.
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Old 07 January 2020, 14:38   #30
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Good luck finding the equations for burning one these days. Apparently you had to order it from the manufacturer in the first place.
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Old 08 January 2020, 07:25   #31
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Hah, yeah, these things are rare enough as is... to find someone with a "PAL B" and get a dump off it is going to be nigh on impossible.

I think the A590 will still work with the PAL A - I'll just lose my contiguous memory space
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Old 08 January 2020, 07:36   #32
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Based on the memory map you posted before, it will work.. At least the A590 contains 2MB of contiguous fast ram.
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