Way back in about 1992, I finally had enough money (ok, well, enough credit) to finally expand my Commodore Amiga 500 to how I wanted it. I previously had an A501 memory expansion module and an external floppy...
keith
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Amiga A501 Replacement
Schematics now available for A501 replacement card
Schematics now available for A501 replacement card!
Find them on the main project page, located here.
Added some new photos for A501 replacement
Added some new photos of the populated PCB for the Commodore Amiga A501 memory replacement card.
Find them on the main project page here.
Cause of original instability and boot problems on the original A500 identified
So the very first A500 I had been testing on since the beginning of the project had a Bug Katcher installed. It turns out that I wasn’t really using it, but I left it plugged in anyways. I’m not sure...
Sweet success, card works 100% in different DUT(Amiga)
So I think the Amiga 500 I was testing with has problems. I’m not sure precisely what or why but Today, I dropped my new A501 replacement card into a known-working Commodore Amiga 500. It fired up immediately no...
Logic Analyzer probe loading seems to fix boot issue
While I had my logic analyzer connected to my memory card tonight, I noticed that I no longer had the white screen hang on bootup problem that I’ve been plagued with since this card came in. As a matter of fact...
Stress testing the memory board
So I’ve written some assembly in the monitor software I’ve been using, and I’ve just created a large loop to see if I can get the card to fail. I’m still having plenty of problems on bootup, but...
Amiga VSC
Bug Katcher on Agnus
I swear I already posted about this but heck if I can find the post. Anyways, here’s a photo of a bug katcher installed on Agnus on a Commodore Amiga 500. This gives me the ability to attach a logic analyzer to...
EEVBLOG does a video teardown on the Amiga 500!
Dave just posted this! I’m so glad to see him take this on!
progress on amiga vsc made this weekend, VSYNC problem persists
Worked on the Amiga VSC this past weekend at Notacon with my super smart friend Brian P. We made some progress, including eliminating all but the smallest HSYNC related bugs. There is still a problem that is haunting...
Cause of most of my noise is likely a sample error
I haven’t put much time lately into the amiga VSC but I put in a little tonight. I’ve got the image cleaner than it has been, but there is still noise on the left hand side, and a left-center band of...
Video artifacts present in scan doubled video
I uploaded a video to youtube that shows some video artifacts happening with the scan doubled video. The entire video shakes as if interlaced, but it’s not. Original res 320×200(15.7khz), doubled to...
Removed the black bar, amiga VSC is starting to work much better
Here’s a screen shot of the amiga vsc in action. As you can see, there’s been much improvement from the last session. Even though I am now passing the amiga’s VSYNC through the FPGA to the monitor, I...
