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scuzzBlog: Diaries September 2019

Entry 17th September 2019: Post 01: Amiga 500 - RAM expansion by the trapdoor.


Amiga 500 - RAM expansion by the trapdoor.

One of my most favourite computers to obtain during my collecting
years was the Amiga 500. Most were sold as is and rarely mentioned
any memory expansions and the like. First thing I did when I got
a 500 was open up, cus previous users would embellish and expand
their 500s in the most imaginative ways. Often there would be ROM
switchers, but the holy grail was the accelerator. Magic times.

Modest expansions for the 500 involved the trapdoor RAM. Sometimes
fitted with a battery which gave the computer a clock to keep time.
There can be an issue with these boards as they often used a barrel
battery which can leak. Later on in the life of the 500, Commodore
started shipping 500s with the A501 cheese RAM upgrade. Sadly the
unit is sealed in a metal case making the battery concealed. Very
often these boards would be damaged beyond repair due to leakage.
They are not that tricky to crack open, unlike the A601 which I
managed to burn a whole in my hand trying to de-solder.

The RAM cards are very neat and also very easy to fit. Just crack
open the trapdoor and slot it in. The cards also had a switch for
disabling the card for what ever reason.

And so here are a few that I keep out. Most of mine are actually
fitted to A500s. It is worth noting that Commodore were very clever
in the design of their motherboards giving the option to expand the
computer without actually opening them up and invalidating the
warranty. The computer I show here still has the warranty seal
intact. It also has a barrel battery on the card. I could remove the
battery but given that it is low risk in terms of damage to the A500
I just leave it on the board and take a look every now and then.

Amiga 500 - RAM expansion by the trapdoor.


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Last updated 17th September 2019

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