Search results

Installing an 8•24 GC display card fixed the video problems. I might only need to replace the cap on the old card to make it work, but I'd rather use the proper accelerated Apple one anyway. I also cleaned and lubricated the floppy drive, so it now loads/reads/ejects disks properly. Sound also...

No luck, the problem persists. Also I'm having power-on circuit issues, which is not a new problem, but worth mentioning. If power is applied, it boots. If I shut down, it immediately reboots. This is with a new power supply from a 7100.

Recapped. Not pictured: the cleaned board. I'll try it out later when it's dry.

Caps arrived. I'll install them this weekend and we'll see how it goes.

A friend of mine mentioned that it might be a sync-on-green issue, which might explain why darkness causes issues. Tomorrow I'll take a look at the output with the oscope on my logic analyzer to see what the signal looks like.

I have a Macintosh IIcx with a 14" color monitor (M1787) that has some issues. When anything dark is drawn close to the left screen edge, a dark splotch runs across to the right. If nothing is there, it looks mostly fine. Any idea what might cause this?

Oh, Linus Åkesson's stuff is awesome. Recently I read about the Macintosh Display Card 8/24 GC, which is a nubus display card that uses an AM29000 RISC CPU to do quickdraw operations on its framebuffer. One of the particularly neat things about it is that it can operate as a NuBus master, which...

I think all you need is a .edu email address.

Hey no problem, we've touched on a bit of everything here! The board I have is the Digilent Nexys2, which I got a few years ago for $100 with an academic discount. Apparently they have a Nexys3 now, with a Xilinx Spartan 6 (vs the Spartan 3 on my board). If you get that one you can use the new...

Couldn't leave well enough alone... I had to go back and add some counters and offsets to make it scroll. I know everybody in the history of everything has done a XOR effect, but it's still pretty cool to do it yourself for the first time. Next step is to add a framebuffer. I'm not sure how...

Hooray, colors! I worked on that last night and today. Lots of learning about the xilinx toolchain, verilog in general, and VGA signals. Finally got it!

Hey all, I haven't popped in here in a while, so I wanted to give a quick update. I have my Digilent Nexys 2 FPGA board set up, and I've got all the development tools installed in linux. I tested out some VGA signal generation code from a friend, and it works! I'm not going to use his though; I...

Yeah, Minix! I remember Bill Buzbee got it running on his wire-wrapped TTL CPU "Magic-1." Seems like a good option. Hah, "life and stuff," always getting in the way. Big things (good things) are happening with me at work these days, which keeps me quite busy, but in a couple weeks my project...

That cypress psoc looks fantastic. Very interesting. I had seen the freesoc before but I didn't think it was anything more than a funky arduino clone. Hah, yes. I suppose I was trying not to seem completely self-serving in my characterization of linux systems, but I do agree with you there. On...

I won't argue with that, haha. Edited to add: Part of the reason I seem all over the place is because I'm thinking very long and hard about what it is I really want to do. I've been sitting here writing and thinking much longer than I would like to admit (hah), but I think this post is a big...

Oh, re: continuing this as a software project. I think that's what I'll do. Well, sort of. The only development board I have right now is a 500k Xilinx Spartan-3E board, so I'm going to see if I can put some sort of soft core on there. I'm hoping it's not as difficult as I imagined.

Man. Everything you're saying is sensible, and that really bums me out. I suppose bare microprocessors don't really make sense for manufacturers to make anymore. Like you said, using a SoC isn't really building a system "from scratch," but it's all I had to work with if I wanted to use a modern...

Hi guys, thanks for all the responses! You've given me a lot to think about. To start off I'll try to explain my goal a little better: I'm taking inspiration from the old 80s microcomputers. I want to build something simple & hackable with some external bus expansion slots, video output...

Hey all, I don't know if any of you remember me, but quite a while back I was interested in building my own 68k microcomputer. The best way to understand what I was shooting for is to imagine what an Apple II would be like if it had a 68k processor. Unfortunately, that path kinda petered out...

Thanks, that explained it nicely! Some of the tricks built into these old systems are quite fascinating. Anyway, the reason for my curiosity: I'm working on building my own computer on an FPGA, and I'm taking some inspiration from the older macintosh systems. I don't think I'll copy this bit of...