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  1. chuma

    eMate 300 / N2 Platform memory initialization

    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...
  2. chuma

    eMate 300 / N2 Platform memory initialization

    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...
  3. chuma

    eMate 300 / N2 Platform memory initialization

    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...
  4. chuma

    Advice for removing a vintage LCD screen cover...

    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.
  5. chuma

    eMate 300 / N2 Platform memory initialization

    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 ...
  6. chuma

    eMate 300 / N2 Platform memory initialization

    @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...
  7. chuma

    eMate 300 / N2 Platform memory initialization

    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...
  8. chuma

    eMate 300 / N2 Platform memory initialization

    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...
  9. chuma

    eMate 300 / N2 Platform memory initialization

    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...
  10. chuma

    eMate 300 / N2 Platform memory initialization

    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...
  11. chuma

    Advice for removing a vintage LCD screen cover...

    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...
  12. chuma

    NEC Ultralite PC-17-02

    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...
  13. chuma

    Einstein, the NewtonOS Emulator

    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...
  14. chuma

    Einstein, the NewtonOS Emulator

    For sure , go to messagepad.org
  15. chuma

    Einstein, the NewtonOS Emulator

    Anyways, yes, I've used and contributed to Einstein, mostly just to fix bugs in the Linux version (since that's my OS of choice) and to trace through the NewtonOS boot process for ... reasons. For actually using NewtonOS on a desktop though, I find myself missing the stylus after a few short...
  16. chuma

    Einstein, the NewtonOS Emulator

    @splorp That Windows download binary link looks very very suspicious and NOT official! I think someone with commit access got hacked .... Matthias has proper download links on his site: http://messagepad.org/Newton_Installs.html
  17. chuma

    eMate ROM question

    ... somebody mention my name?