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The drive is polling based. There are places where it polls the command port and waits for a bit to go low, which is basically "interrupt has been requested". There is also an external interrupt pin, but this BIOS doesn't use it The "reference" implementation is in the schematic at...

Yeah, the commercial card sort of sucks. The fitment is bad-- the port sticks wildly out of the back of the case-- and it's inflexible in configuration. I know there were a few designs for other cards being mocked up earlier in the thread, but I don't know if any of them ever made it to actual...

WRT to 2C0, I removed it from the latest version. As much as anything, its value was to let me easily generate a failure-to-detect for debugging purposes. WRT to 260, I don't have one to say. I feel like in that situation, the EMS board has to give because its ports can be reassigned without...

Updated the auto-detect version: Trimmed some messages to drop down below 4096 bytes again (double-wide mode-- the unrolled loops in 8086 mode mean single-wide exceeds 4k), and changed the ports we scan for a CH375/6. It should look for E4/E0, 262/260, and 2C2/2C0 in 16-bit mode, and E4/E0...

Okay, a more interesting experiment in user-friendliness: https://gitlab.com/hakfoo1/ch37x-bios/-/tree/auto-detect Built as a separate branch because it's a bit of a high-risk offering. At initialization, instead of having one or two drive ports hard-coded, it scans a list of them in the ROM...

Primarily a cosmetic update today. I had grand visions of "hey, I can finally fix where at some point around v0.8 a couple of specific cheapo flash drives stopped detecting" but they seem to work again. So I restructured the power-on messaging to be more compact and, fairly blatantly, follow...

Does it also come back with an "inert" probe like a scrap of cardboard or plastic to press on the pin? Maybe a cold/cracked solder joint that loses contact outside of a certain temperature range?

I heard a comment from someone in Discord who bought one claiming "The seller just sent a copy of the manual and BIOS, including the GPL copyright etc." I wonder if that (at least in part) fulfills their requirement for source distribution; as I understand it technically they only have to...

A19 will be low in all addresses below 0x80000, the lower half of a 1Mb memory map. If the chip select is active low (as it is on the AS6C4000, at least), that means that you can wire the A19 pin directly to the chip select of the lower 512k RAM chip, so it's super easy. When you're accessing...

There's not really a point in doing so. The 80186 only has the 20-bit address space, so you can only reasonably cram 1MB into it with straight addressing. If you wanted to do something more complex, like bank switching, you would need some way to engage that, and it would likely be its own...

As I see it, you have two choices: You can use the chip select pins of the 80186; in that case, you'd need to design a boot ROM that will fit in the top 1K so it's ready to run at power-on, and provides enough functionality to define the rest of the memory map before handing over to code...

It's not really an "ISA backplane" so much as hijacking the CPU socket. Notice most of them have a cable that ends in a 40-wire plug that replaces the 8088 CPU. I suspect most of the logic in the cards is devoted to a few things: * Buffering and repackaging 16 or 32-bit memory and I/O requests...

I'm pretty sure it was a flash over IDE. I don't recall having to mail it away and those are drives you can't easily release the PCB for a swap after all.

I just wanted to share my anecdote with the JTS drives that apparently inherited the Kalok legacy. Around here, the local Fry's Electronics was selling the C3200-2AS as a loss-leader special at one point. I put one in my 486 because I believed my 120Mb Conner was shot (astonishingly, it was...

Just in case anyone is following my particular drama, I found that the drives that weren't reliable when hooked via direct SATA worked reliably through an old parts-box USB 2.0 to SATA/PATA adapter. Supposedly there's some noise about optical drives being happer in "IDE style" mode than "ACHI"...

I'd sort of wonder if some of the rules about timing and compatiblity between families have changed over time. I'd assume many of these parts are fully mature manufacturing wise, but at the same time, specs were set long ago. Would, for example, new 74ALS series parts be fast enough to...

Don't all C128DCRs have a 64k VDC, so that's at least one surefire check? I need a comical chain of adaptors to convert RGBI to a monitor I own. :/

I've been having some zesty issues with CD reading. My modern machine has two older optical drives. One started to give up the ghost, so I bought a new one, and noticed I was getting weird noisy CD rips. The old drives tend to get correct results when using software that references the...

For what it's worth, I've done some experimentation with an XT-alike using a 20MHz-rated NEC V40 with somewhat modern support parts. (XT-IDE and CH375/6 cards instead of legacy hard drive controllers, 55ns SRAM/70ns ROM, new build serial/FDC card) For high bus speeds, you could get to 20MHz...

Judging by the markings on the main IC, it seems to be something like the Nintendo Switch or possibly Switch Lite.