Recent content by halkyardo

Not a Mac, but I just got a new toy from across the pond :D

I may have gotten the technical specifics of the sense code wrong in that thread, it was a while ago and I was working off of a scrawled pile of notes that I may have gotten wrong. What I *can* confirm is that the Futura SX in the IIfx that's sitting next to me right now is outputting 1024x768...

Not in the driver, unfortunately - any packets that come off the wire with a bad checksum are rejected in the ethernet controller without the driver ever being aware of them. And on the transmit side, the ethernet controller calculates the ethernet checksum at transmit time. This is convenient...

Yes, as discussed in the thread I linked in my last post, it does not use the standard monitor sense codes for 1024x768 (and 1152x870). It uses an otherwise-undocumented sense code, and the small rotary switch that's on the top edge of the card. The sense code that is required is SENSE0...

Oh definitely - if the computer thinks there's a display attached, the card probably isn't doing monitor detection, so it'll be outputting a valid video signal even with nothing connected. You'll be looking for a very 'analogue-looking' signal on the R, G and B pins that repeats every 16 or so...

The Bt458 RAMDAC on that card supports 8-bit RGB output, so it wouldn't surprise me if it was a colour card. There does seem to be a de-facto standard for analogue RGB video on a DE9 connector, based on the pinout of the IBM Professional Graphics Controller - the same pinout shows up on Acorn...

That chip looks to be a resistor-capacitor network of some sort rather than a logic IC, probably providing termination for a bus or something rather than a logic function. It would be trivial to identify a replacement part (or even fabricate an equivalent from scratch), if its properties are...

That certainly is a contraption, I love it! A signal integrity issue would not surprise me; I was having bizarre display corruption issues with a video card attached to the pass-through slot on mine, and it turned out to be ringing on the C16M clock line upsetting the video controller chip. I'm...

Hooray! Glad that's all it ended up being! If you don't mind, would you be able to run Helios LanTest and let me know what your read and write performance looks like? Just trying to gather more performance data for various machines. Thanks! That's exactly what I was aiming for with the...

I've had a chance to sit down and play with my logic analyzer tonight, and of course now I can't reproduce the issues that I was having with the card in my IIfx - it works just fine, I think I might have just forgotten to change the slot-ID jumpers when I said it wasn't working. Oops! Looking...

New hardware project: an adapter to connect an HP logic analyzer directly to the PDS slot of an SE/30. Mostly just built it out of curiosity, but it could be a powerful tool for troubleshooting faulty machines or developing new hardware. Expect a writeup soon :)

This is extremely cool! I'm not really familiar with the internals of the 512 to review your design in detail, but looking at your notes and the reasoning behind them, it seems like a sound idea to me. I'll be following this with great interest!

Does it work if you put the original ROMs back in? If so, then my guess would be either that you've got a shorted or missing trace somewhere on your ROM board, or your flash chips or the data that you're programming them with are bad. As a start, I'd recommend cross-checking every pin's...

Actually, that screenshot of the manual reminds me of something - there's a switch internal to the headphone jack that is supposed to disable the internal speaker when something is plugged into it. It's not unheard of for these switches to get dirty and prevent the internal speaker from working...

Did you remember to plug the 2-pin speaker connector back in when you put it back together? It's easy to miss, especially if the cable has fallen back into the upper part of the case. As far as getting the case to close up, mine is a little bit touchy about that too. Make sure that the...