A computer kit from the '70s: Ithaca Audio Z80 CPU card for the S100 bus

Haven't had much time to write on my blog lately (lately being the last 5 months or so), mostly because of my job, but also because I spend most of my time doing things and saying "oh, it would be cool to blog about this once I'm done!". Then I'm done, and immediately find something else to do before I find the time to sit down and write about the last thing I did. That's how I am.

Anyway, I REALLY wanted to blog about this little project I spent a few evenings on, so here I am.
But first, a little background: do you, Reader, know about the S-100 computers? If yes, skip on, if not, I'll try to be quick and painless, leaving in-depth history and tech to specialized websites like this one.

Altair 8800 + 8" floppy disk system.
Image courtesy of Wikipedia

Building the XT-IDE. Part 3

Thanks to James Pearce I've finally completed my XT-CF v1 card!
James is the designer of this board and he provided me the code (which you can find HERE) to program the Xilinx XC9572XL CLPD to make it usable with recent revisions of the XT-IDE Universal BIOS.

The XT-CF v1, ready to be tested!

Exhuming an old project: Building the XT-IDE. Part 2

Between all the small packages the postman left at my door today, I got one with a few 74F573 logic ICs inside: just what my XT-IDE was missing to get basic functionality (to get the serial port working I still need the proper oscillator)!

XT-IDE being tested with a Disk-On-Module

Exhuming an old project: Building the XT-IDE. Part 1

I finally received the correct Xilinx CLPD part and the missing 74LVC1G14 for my XT-CF v1 card, so I could complete the build.

Soldering the CLPD avoiding shorts was a bit of a challenge, but a good measure of flux helped immensely. Now the board is ready to be flashed with the correct programming through JTAG. I'm waiting for a BUS PIRATE to accomplish the job.

Exhuming an old project: Building the XT-IDE. Part 0

While cleaning up my closets (a task I make sure to accomplish at least once every ten years) I dug up two bare circuit boards from a project I undertook one or two years ago, and never completed: fitting my old XT computers with a decent and relatively new storage system.
Fitting IDE disks in such old computers can be a daunting task, if one decides to stick with then-contemporary technology the only decent solution would probably require finding an 8bit SCSI controller (with autobooting: hard!).
Lucky me, I did not want to limit myself to old tech and decided to check some homebrew options: the XT-IDE and XT-CF boards:

The two boards, both almost completed...

Both cards allow a modern IDE/CF

Playing with pixels

Being the old-hardware maniac I am, I bought an MKIII Myth flash card from ic2005.com to play my (regularly bought at flea markets) Master System games without having to keep all the carts around. A nice side-effect of flash carts is that they let you try your own code on game consoles: in short, you can write and play your own games!

I've already done some homebrew console development on Nintendo 64 and SEGA Saturn, but the Master System is a different beast: being older and more limited, high-level languages are out of the question (Well, actually you CAN use a C compiler: see z88dk), so I'll have some fun learning Z80 assembly!

In the meantime, I tried drawing a sample tileset (keeping hardware limitations in mind, and beware: I'm no artist!) for a game idea I have:

And here is a level mockup made with the tileset:

It's set in a weird farm... Will go more in depth describing it some other time, if I can go on developing the idea!