WTB: Chip RAM expansion for A2500

[McVenco]

I'm looking for a Chip RAM upgrade for my A2500 (currently the machine has 1MB on board, so an upgrade to 2MB). The upgrade must not interfere in any way with my other expansions (4MB Zorro RAM card and A2630).
Anyone want to part with one of these?

[alexh]

MegAchip
MiniMegi
Megichip
Chip-2MB

You'll NEVER get a PAL one. I've been looking for four years.

You'll have to buy an NTSC one (which come up from time to time on ebay) and butcher a (broken?) A600 to get the compatible 8375 2Mbyte PAL Agnus.

[McVenco]

Well, if the only difference between a PAL and an NTSC version is the Agnus chip then it's no problem - I've got 2 or 3 of those lying around anyway - came from broken A500(+) boards and I also have an A600 lying around. So for all I care it could come without the Agnus - as long as there's a socket for the Agnus chip because my soldering skills are pretty much non-existant :-)

[Zetr0]

McVenco

The A500+ Agni (390544-01) 8375 are not (PIN) compatible, from my studies they have a pin shift that would need a correction of 30 - 40 signal lines.

[alexh]

Originally Posted by McVenco

It could come without the Agnus - as long as there's a socket for the Agnus chip because my soldering skills are pretty much non-existant :-)

The Agnus in the A600 is surface mount so you'd (ideally) use a hot-air gun to remove it. I wouldn't want to use an iron.

[Zetr0]

smd component & iron = bad

smd component + flux + hot air = good

[gklinger]

Originally Posted by alexh

MegAchip
MiniMegi
Megichip
Chip-2MB

Do you think any of those would work in an Amiga 1000?

[McVenco]

Originally Posted by gklinger

Do you think any of those would work in an Amiga 1000?

Nope, they won't. The Agnus in the A1000 is a DIP, rather than a PLCC chip, so it doesn't even fit...

[alexh]

A1000 has 512kbyte Agnus too so non of the address lines will be there.

Any chance to get more ChipRam on a A500 Rev 8A Board? I only have 512KB, want to have more (up to 2MB would be perfect)

[gklinger]

That's too bad about the 1000. It really is my favourite Amiga and I've been mulling over the idea of trying to beef mine up (further) to the point that I could use it as my primary Amiga. That wouldn't really be practical if I could use WHDLoad and I'm not sure that 512K of chip RAM will cut it. Oh well. I'm feeling guilty about the fact that my 1000 just sits there looking pretty and doesn't get much use.

[alexh]

Originally Posted by Retreaux

Any chance to get more ChipRam on a A500 Rev 8A Board? I only have 512KB, want to have more (up to 2MB would be perfect)

AFAIK you cannot have a REV 8A and only 512KByte chip RAM because the A500 Rev 8A was an A500+ and they came with 1Meg out of the box.

To increase to 2 Mbytes of chip RAM all you need is to add a 1Mbyte A500+ trap door RAM expansion (e.g. A501+)

[McVenco]

Originally Posted by alexh

AFAIK you cannot have a REV 8A and only 512KByte chip RAM because the A500 Rev 8A was an A500+ and they came with 1Meg out of the box.

Nope, Commodore wouldn't be Commodore if they didn't have something odd there as well.

My first Miggy (bought in 1991) was an A500 (with the wide Commodore A500 label on it). It had a rev 8a mainboard (it even had the name A500+ silkscreened on the PCB), but only 512kB RAM on board. I did have a full ECS chipset (with 2MB Agnus) though... It just needed four RAM chips soldered to the mainboard and there would have been 1MB ChipRAM.




Anyway, my initial message in this thread is still actual

[Fingerlickin_B]

Originally Posted by alexh

MegAchip

You'll NEVER get a PAL one. I've been looking for four years.

I got one...wasn't specifically looking for one either!

PZ.

[alexh]

Where from?

[Fingerlickin_B]

eBay.com.au