Search results

It shouldn't change in operation so once the timing is figured out it should be fine. Someone with a faster scope could try changing the "side 1" on the next to last line to "side 0" it'll change the output to do a fast square wave at 2x pixel clock with it going high when sampling and see how...

Hmm, my PIO program runs at twice the pixel clock in order to have time to do the necessary looping logic so it might actually be sampling in the middle of the pixel already. If not, it would be trivial to add a 1 cycle (1/2 pixel) delay to before starting the capture loop.

I've got the basic scanline timings working on a PIO. H-Blank: Right now the program is just NOP-ing instead of reading a pin because I don't have the reading part built out and Mu hates it when I print tons of numbers. I'm driving a side pin high while in the reading pixels loop and low...

I don't think this site is specifically for vintage stuff, as long as you're Tinkering with it it seems like fair game

The PIO units do their own IO on their own clock, so there's no need to use the SPI engine. It can delay X pixel clocks after detecting the end of HSYNC and then start reading on the next cycle. By default GPIO reads will be queued for the main CPU in 32-bit words in a 4 or 8 word deep FIFO and...

The PIOs do fractional clock dividing. A quick test in circuitpython say `real frequency 15663240` when I request 15.6672MHz, that might be enough to hold for 1 scanline. My Salae logic analyzer only does 12MS/s so I guess it's not fast enough to capture individual pixels but when running a...

The Pi Pico's PIO units should be able to be clocked to sync up to with the Mac and easily get accurate pixel samples without having to oversample. Some math would be involved to figure out how to divide the system clock (48MHz) down to the pixel clock and setting the PIO unit to run at that...

you shouldn't need the power supply from the enclosure, the BlueSCSI should get all the power it needs from the termination power provided by the computer.

It probably isn't that smart. I'd bet it's just presenting the whole SD card as a disk with a simple 1-to-1 sector mapping. You can probably use Balena Etcher or something similar to write a pre-made image to the drive. A modern Mac would probably be able to mount the SD card and add files once...

That second one is a passive SCSI adapter, so no help there, and it would be way too big to fit into a powerbook. The first one is for the very-rare outside of pre-touch screen iPods 1.8" drives. They probably had to split the power over more pins than the 44-pin laptop standard because those...

is it wrong that I want to hack a bridge to these forums?

...a couple more pennies on the floor... I suspect that the detailed categorization will help down the road as a long term information repository rather than just the "what's happening today" chatter. I thought that part of the idea behind TinkerDifferent was to grow a repository of knowledge...

an external Active terminator instead of the passive resister nets on the *SCSI emulators would probably work better

That's normally because somebody is watching you with Apple Remote Desktop or VNC. On a stand-alone machine that's very suspicious.

I'm curious how experiments with different resonating chambers, or maybe just sticking the relay up against the case, to get a richer sound work out. I don't have a BlueSCSI, or anything to put one in, or I'd try it myself.

I'm seeing some weird huge lags when telneting over the PPP connection on MacOS 7.5. I need to do some more packet captures to try and figure out what's going on. The same modem on a Linux machine seems to be able to maintain the telnet flow so I don't think it's the modem itself mangling...

Nice. Next year maybe someone will make an HTML/JS HyperCard player using these docs and whatever the latest and greatest new JS app framework is at the time.

hmm, sounds like over-termination. Both ends being terminated is proper, but I suspect one or both of the emulators aren't capable of sinking enough current to drive a bus terminated on both ends. The new chips are too power efficient, they aren't made to slosh around as much power as those of...

This doesn't sound like it's very structured data. Would a searchable wiki be a better fit for this information? MediaWiki lets you create a little bit of structure in largely unstructured data, as caps.wiki is demonstrating. A few tags and/or categories for automatic grouping and listing...

I left it there since I don't have anything that I could plug in either side to. If somebody has a use for it I could go back and grab it and toss it in the mail.