Amiga with broken chip

When trying out my new Gotek drive, My Amiga did her own thing.
When the Selector.ADF was loaded, the selection bar keep on scrolling down.
Checking the joystick circuit, I noticed another resistance between pin2 of joystick port 2 than the other pins.
First I checked the Resistor pack RP401 but it seems ok.
Then I replaced U15, a 74LS157 (multiplexer) this fixed the problem.

My Amiga is now running again.

Near death experience

Yesterday I was busy building a bootselector with a 74ls241, when ready I checked for short circuits, everything looks good.
But when powering the Amiga some smoke appeared from her…
I double checked the circuit, but couldn’t find any error..
I removed the 74ls241 from the schematics and used a 4 wire cable to connect the switch.
I wanted to use the 74ls241 to avoid having big cables running through her.
I tested the bootselector and it worked.

 

Searching for memory

To upgrade my Amiga 500 (rev 5.) to 1 Mb chip ram I need an A501 extension board or 16 ram chips.
As I can’t find an extension board, I started to look for 16 4256 or 41256 fast mode dram chips.
on Ebay I can find them for $2.50 per piece (so totaling $40.00 without shipping), this is to expensive for me, so I continued my search.
I found some shops that still sell them, but most are in the same price range (or charge high shipping costs for shipping to Europe).

But I seems to find one place now, but I’m not sure if this are the correct ones.
I send them a mail, asking for the brand, so I can check the datasheets
Check the Futurlec website, the part number seems correct, and for $0.95 per piece.