Anyone recognize this Amiga 500 512kb expansion card?

[StoneOakvalley]

I've looked over the entire database on Big Book of Amiga Hardware as well as numerous google searches and do find very similar ones, but not this particular one.


There are no markings, names, logos etc. on this = super hard to start any search.


It's (most likely) history:
Believe it came with an Amiga 500 Norwegian 1.2 kickstart machine which I repaired the floppy drive on in 1992-93. After the repair, the owner had lost interrest in it and just gave me the entire Amiga 500 :-)


A decade later, I removed the leaky battery and replaced it with a more modern solution, however, things were quite a mess as I did some work with it using a very very bad soldering iron.


Fast forward to this week, the 1.2 Amiga 500 is working great, but upon power on there is a bright yellow flash, then 2 grays and ends with a static yellow screen, red power led blinking and Amiga resets. After 1 reset, it goes to dark grey first, then yellow screen static and repeats forever.


Now, at the moment I have no way of testing the 41256 chips on it, but will in future. Another thing that bugs me, looking at other similar expansion designs from the 90's, there seems to always be 1-2 additional capacitors (those blue drums), however on this card there is none.


Just hours ago, I removed the entire RTC section and all of its components to see if that caused any change in behaviour. But, still yellow screen.


I have 4 other Amiga 512KB expansion which works great on this machine, so nothing wrong with the 1.2 machine, and if this card is inserted into any other 1.3, 2.04 machine, same yellow screen occurs.

[spannernick]

Look up the ICs on it and it might give you more info on them, they look like they are all the same on the 2 rows and one that might be different is the one its own.
All I can say is it looks like a ram card and look like it has a Real time clock and a lot of ram, it could have 8mb ram on it, each IC could be 0.5 mb.

[SkulleateR]

Originally Posted by spannernick

Look up the ICs on it and it might give you more info on them, they look like they are all the same on the 2 rows and one that might be different is the one its own.
All I can say is it looks like a ram card and look like it has a Real time clock and a lot of ram, it could have 8mb ram on it, each IC could be 0.5 mb.

Nope ... it uses 41256 Ram, for 16 ICs it would be 512KB all together

[giantclam]

No clue to maker, but seems the same board... https://www.reddit.com/r/retrogaming...ga_500_memory/

Capacitors are present, just a different colour.

Ramfield looks like a gaggle of used/2ndhand chips with a couple of new chips ; you'll need check them all obviously =)

[Photon]

This is a bog standard 512k expansion, but it has a clock. and resistors.

Doesn't need branding, there was a great demand for these and so noname brands were common!

[StoneOakvalley]

@giantclam

Wow, that looks the same, at least now I know what's supposed to be of components, thanks so much!