ilike8bits

Upgrading the VRAM in a Quadra 950

So you have a lovely Macintosh Quadra 950 with only the onboard 1MB of VRAM, and you want to upgrade it to the full 2MB? Here’s how. Firstly you will need 4 sticks of compatible VRAM. These come in either 256K or 512K sizes. While you can use 512K sticks, only 256K will be visibleContinue reading “Upgrading the VRAM in a Quadra 950”

Some upgrades for the Quadra 950

Thanks to the ever generous Greg, I have received several NuBus cards to my Macintosh Quadra 950. They’re provided in a “unknown” state, so it’s going to be a fun job to install some of these and see what we can get working… So what do we have here? First up we have a generousContinue reading “Some upgrades for the Quadra 950”

The Archimedes is back on the bench

Now I have an oscilloscope, I thought it was time to break out the Archimedes. So far it has resisted my attempts to diagnose exactly what is wrong with it but I will persevere. Symptoms are the same whether I use a Gotek or a real drive.When you try and access the drive you getContinue reading “The Archimedes is back on the bench”

Posting will slow for a while

So I’ve gone back to work after an extended holiday, so output is likely to slow for a bit. However, I’m still doing retro “stuff” so I thought I’d share some of it. One of the coolest projects I completed on the weekend was building an MT32Pi Hat. This consists of a Raspberry Pi runningContinue reading “Posting will slow for a while”

Expanding on removing corrosion caused by batteries.

Recently in a Facebook chat, the question was asked: “How do I deal with battery acid damage so things don’t get worse?”. Having recently dealt with both the Quadra 950 and the Amiga 2000, I felt eminently qualified. Here is my answer This is my method. There are many like it but this is mine.Continue reading “Expanding on removing corrosion caused by batteries.”

Understanding Memory Chip Codes

I wrote this up for a forum post and thought I’d share it here. It’s not 100% accurate but is “good enough” to help in a lot of cases. The discussion started with a poster trying to understand how we knew what the capacity of a 41256 RAM chip was. It’s actually there in theContinue reading “Understanding Memory Chip Codes”

Bits and Bobs

Well, here we are again. Amiga 2000 I built up the -5v rail for the A2000 and fully reassembled it. Unfortunately the A2000 is presenting with a black screen. No synch or other signs of life. Not the end of the world, but it does mean it’s on hold until my new Oscilloscope arrives. MacContinue reading “Bits and Bobs”

A Tale of Two Systems (And their Horrible Batteries) Part 1

In parallel, I’ve started fixing both the Amiga 2000 and the Quadra 950 boards. Both had extensive battery damage. In both cases I’d neutralised the battery alkaline with vinegar, water and isopropanol washes. I started with the Amiga. AMIGA 2000 Evaluating the board, I ended up pulling off all components and sockets in about aContinue reading “A Tale of Two Systems (And their Horrible Batteries) Part 1”

Updates and some Smaller Projects

Well I haven’t stopped working on projects and while some of the have been successful, others have not been so successful. It doesn’t help that my desoldering station has broken. I just need to get some specialised glue to fix it. Archimedes The Archie still has a bunged Floppy Disk Drive and I’m stumped asContinue reading “Updates and some Smaller Projects”

Building a computer (Omega MSX)

One thing I’ve wanted to do for a very long time is to build a kit computer. Originally I planned to build a Spectrum 128k clone. I’ll probably still do that in the future, but as I had a Spectrum already, there was less pressure to get another speccy. I kept pushing it back. ThenContinue reading “Building a computer (Omega MSX)”