Search results

Just got the ATX/VGA/SE adapter boards: Looks good, just gotta add the two 74LVC86 gates and the VGA port. Still waiting on those parts from Mouser or somethin. And here is our new logotype on one of our other products: This thing is a board but doesn't serve an electrical function so we can...

Thanks James for the audio recordings. Turns out all I needed to analyze was the first note! Using Audacity's auto-correlation analysis, which I honestly don't understand at all, I was able to locate the 60 Hz artifact I was referring to. Here's the auto-correlation graph of the "good sound"...

A lot of software compatibility issues could be worked around more effectively if we developed our own 68k core to be put on an FPGA. We could make it do single-cycle execution like the 68040 but would be software-compatible with the 68030. Nothing I'm aware of quite fits the bill to accelerate...

The cause of the problem on the "Mac I" series (i.e. 128, 512, Plus, SE) and on the "Mac II" series (II, SE/30, etc.) is at least slightly different because the machines' audio systems work differently. On the "Mac I," the vblank interrupt occurs every frame, during which the Mac redraws the...

Thanks! Oh also, no need to do the whole 192 kHz / 24 bit. The Mac is only 22 kHz / 8 bit so (according to the well-known Nyquist-Shannon theorem) CD-quality 44.1 kHz (or 48 kHz) / 16 bit will more than suffice. The distortion is a digital artifact after all, not some kind of analog issue where...

Yes, I would like to implement this. One of my final changes to the WarpSE was to tap the /IPL2 interrupt line which connects to the programmers' switch. This was in pursuit of the goal of eliminating the need for the DIP switch. Therefore I would like to support selection of one of the...

Tindie is okay but we actually pay less fees on eBay than on Tindie. Since we sell a good bit, we’ve gotten whatever eBay subscription gets you the reduced fees. We also list our (new manufacture) gizmos in categories like “PC Hardware - RAM” instead of “Vintage Computers - Parts and...

We (Garrett’s Workshop) sell our products on eBay and Tindie, so you’ll be able to buy it on there as usual.

Hmmm yeah good idea I'll have to think about this. But we have no good logo! So the badge would be kinda boring lol. The costs break down like so: SMD capacitors and resistors - $2 (1) 3.3V voltage regulator - $1 (2) 2Mx8 DRAM - $5 (2) 512kx8 flash - $5 (13) 74AHCT573 latching buffer - $4 (1)...

Could be. I can investigate in the future if we do an SE/30 accelerator. Yes, the reason is that the 68HC000 was only ever officially specified for 20 MHz operation. 25 MHz is technically "overclocked." However it is widely understood that nearly all 'HC000s (especially later mask revisions)...

I’m confident we can do the first 100 production units for $125 each but after that there may be a price increase to $150ish. Edit: Oh, also there will be a surcharge of approximately $15 for shipping outside of the United States. Shipping anywhere in the US is free. :) You’re on our short list...

But also, "real artists ship!" So we have reverted to the old temporary logotype: The prototypes are in fabrication!

It wouldn't be that hard to swap it out in the layout but the current design is pretty strictly 68HC000-focused. There are a number of things I'd do differently were I using an '030. Maybe in the future! Okay the current hang-up is just on the logo. Still not sure what to go with. Garrett...

After much deliberation I've decided I should redo this project using a small FPGA instead. The 74xx design is okay but it has too many chips and soldered pins. I'll update with a new schematic and board layout soon.

In retrospect I think it's more like a 4/17 "uneven" or "jittery" division of the main clock to support the AppleTalk (and industry-standard) 230.4 kbaud rate for the serial port since (15.6672) * (4/17) * (1/16) is exactly 230,400.

Nope. The point is just to adapt the pinout @alxlab Is the logo better inverted like you originally did? I think it's better this way than what I posted before:

Nope, too complicated. It just outputs the Mac 512x342 signal. So it requires a monitor which works with the unusual Mac line rate. I've got several HP L2335 monitors which work okay with Mac LC machines at 512x384. So hopefully it'll work on those. If not I will have to buy some kind of...

Yeah, it’s to run the Mac outside of the case so as to hook the system up to a logic analyzer more easily and also to do production testing of the accelerator. Ooh I can try it on a rendered board if you can make a bit higher-res version. Pretty easy, just basically programmable inverters on...

Video/ATX PSU adapter is done! Schematic: Okay it really is about to be prototype time. We don't have a logo but we are trying to be more consistent with our branding by adopting a particular wordmark/font for our products rather than just using the default font in KiCAD or whatever. See the...

Z53C8003 seems compatible but I am not intimately familiar with the workings of the 5380 so I can't like, look at the datasheet and see if anything is inconsistent. We should just try it lol. As for the SWIM, we can do one better, just emulate a SWIM connected to nothing. Should be easy since...