Search results

I'm having two strange issues with my Sharp PT-9000: I can't get a good read from the resistive touchscreen, and the serial port sends and receives garbage data all the time. I have a hunch (more like a wish 🙏) that these are both somehow power-related problems. Other than that the machine...

You probably already found https://kayprojournal.com/index.php/Kaypro_PC which has lots of info about this machine. It's essentially a PC/XT clone with a passive backplane instead of a motherboard. With a Raspberry Pi Pico, a level shifter (or circuitry), and a USB OTG cable, you can build an...

I'm sure that some people still do. My life is slightly complicated and I got hooked by running my own CalDAV server over a decade ago so I could easily share calendars between family members that use either iOS or Android, and didn't want to use GCal. Kinda requires using modern devices at...

I acquired the handheld collection of another local retro collector last year, and it included many PalmOS devices. I haven't catalogued them all yet but I think there's around 20 devices, ranging from a PalmPilot Pro all the way to a LifeDrive. Even some odd ones like TRGPros, Handera 330s...

I recently acquired what seems to be a real unicorn of a device, a Sharp PT-9000 tablet computer, circa 1994. It's a chunky tablet computer with a 640x400 B&W LCD paired with a resistive touch panel, that runs DOS and GeoWorks (PEN/GEOS, I guess?). The hardware is organized around the Vadem...

Could be the screen contrast - slider position or the slider component itself - though if the volume's up then the eMate should emit the start-up sound You mentioned "It has two cards in the slots" - one should be the ROM card with NewtonOS on it, it should be obvious because the card has spots...

I haven't posted any updates here because the Linux PulseAudio output driver for Einstein was killing the emulation performance. Since I hacked/wrote it, I just spent the last 1.5 weeks fixing it. Now that it no longer sucks and the emulation actually runs smoothly and at the proper speed on...

As far as I can tell, Einstein currently doesn't boot with the eMate ROM - it ends up trying to run the diagnostic image from REx0 and falls into a boot loop. Could be because Einstein applies a number of ROM patches in its JIT emulation to work around things that aren't understood or hardware...

Ah, yes, that's a good idea! I started doing that last night, though I've never used Ghidra before. I am not great at reading machine code (it's been a long time since I had to use it in university, and haven't had to use it in my career) so it's nice to get some kind of visual representation...

I ended up warming a hot/cold pack to about 45-50°C and leaving it on the screen for a few minutes. This helped convince the ancient double-sided tape holding the screen cover on to let go. Currently rebuilding the broken plastic and lubricating the hinge spring.

Read the Clean-ROM-Images link that I posted. Essentially, dumping the ROM from NewtonOS reads the ROM space through the MMU, and there happens to be a page of RAM mapped in there. This is a minor consideration, but I'm a bit pedantic ...

@Androda Yup, we're reading the same documentation. The PS-7110 is pretty close to the 7100 - the order of the internal registers between the two is very close. At that point in the boot, the MMU has not been enabled. I should actually go back and check my work ... for some reason I can't...

That's the correct-enough ROM image - it's named with the wrong version (it should be 737041) and it's not 100% clean, but it will do. I started collecting information about actual clean NewtonOS ROM dumps, now that folks have hardware which can read the chips directly...

From tracing the boot process, there is code in the DiagBootStub - a very interesting area of the ROM almost certainly written in pure assembler - that tests whether addresses can be written and then read back, starting with 0x4000000 and 0x4200000 (base RAM and base RAM + 2MB). If the test at...

Thanks to the symbol information included with debug ROM images, and a convenient tool written years ago called `mpdumper` that demangles the symbols, we can look through much of the ROM code for interesting symbols. These are good starting points for tracing code and ROM accesses from...

So the general question being asked here was "how does the system know how much DRAM is available?" There is generally available documentation that leads to the answer. First, we know how to add a new ROM Extension (REx) to patch the OS, thanks to the ROM Board Designer's Guide. RExes...

So I took my original NEC Ultralite out of storage the other day, and decided to open it up for the first time to see what was going on with the hinge - there was a clear gap at the back when it was closed, which isn't good. Sure enough, part of the plastic that holds the top cover to the...

I've owned an NEC Ultralite PC-17-02 for many years now, and every so often I like to take it out of storage and make sure it's still in decent working order. Yup, looks good!! (y) Disconnect battery and back into storage it goes... though it does have a bit of a wonky hinge which I should...

Who needs a bag when your computer has its own handle? For years I've always thought that the eMate 300 was so durable, you could run it over with a vehicle and it would survive... not that I've tried though! As for the screen... all of the eMates in my care came from classroom settings, owned...

For sure , go to messagepad.org