4 ms·

We did look into emulating the Explorer II processor (Hummingbird) since there was more software available for it than the Explorer but the Hummingbird boot ROM

We did look into emulating the Explorer II processor (Hummingbird) since there was more software available for it than the Explorer but the Hummingbird boot ROM is internal to the IC. We needed a working machine to dump the ROM from, and one wasn't found in time.

johndoe0815 3y ago
What a shame :(. I think the only machines I might have access to (again) in the future are also all Explorer Is ("Sperry" OEM-labeled). These are currently 2000km away, but I hope we can move at least one of the machines and get it to work again. Do you think the ROM from the MicroExplorer version of the IC would be useful for the emulator? I think the designation of the chip was different from the one used in the Explorer II, but I suspect the two might still be quite closely related. A MicroExplorer might be a bit easier to find in a working condition... Update (x2, I didn't find the EPROM originally): a MicroExplorer ROM dump is available at bitsavers [1] - 64 kB in size. However, this seems to be a dump of the TMM24512F EPROM on the PCB [2]. The EPROM doesn't seem to contain 68k machine code, which I would have expected in a regular NuBus card ROM, so perhaps this version of the Explorer chip booted from the external PROM? [1] http://www.bitsavers.org/pdf/ti/microexplorer/microexplorer-255_1924-1.rom.BIN http://www.bitsavers.org/pdf/ti/microexplorer/microexplorer-... [2] http://bitsavers.trailing-edge.com/bits/TI/Explorer/pcb_pictures/microExplorer.jpg http://bitsavers.trailing-edge.com/bits/TI/Explorer/pcb_pict...
- Suzuran 3y ago
  IIMU this is the ROM expected by the Mac Toolbox, but I am not that familiar with the guts of NuBus Macs. I haven't touched Explorer emulation in years, when it dead-ended I moved on to LMI stuff and then gave up on lisp stuff completely when working on the LMI stuff attracted a bunch of outrage.
  - pinewurst 3y ago
    What outrage if I can ask? Your LMI emulator (if you're who I think you are) is great!
    - Suzuran 3y ago
      The outrage was primarily centered on what my work wasn't - It wasn't written in (Insert trendy language here) which meant it was an attack on those, it wasn't advancing (Insert cause here) which meant it was an attack on them, it wasn't a CADR, it wasn't Symbolics Genera, it wasn't running on (Insert environment here), and it wasn't living up to the hype surrounding Lisp Machines in general. When I got actual hardware to examine it got a lot worse; nearly all of the feedback I got after that revolved around my being too poor/young/not-famous-youtuber-X/unwilling to part them out. When pictures of my house were posted because I was unwilling to sell a keyboard that was too much. None of this stuff was worth my safety. On top of that, the vast majority of the people who downloaded the emulator didn't even bother to download the disk images or documentation - they just cloned the source repository, did "./configure", and then sent hate mail when it didn't work because the source repository wasn't a release source and required you to do the whole autotools thing. It became a no-win scenario - there was no way I was going to live up to the expectations people had and no way I was ever going to make the gatekeepers happy so I just stopped trying. I moved on to other things that seem to be a lot less controversial and when I do work on something that may be controversial I just don't tell anyone about it.
      - pinewurst 3y ago
        Hell is other people. I thank you for an excellent effort regardless of them. I built it using your very descriptive docs and images and it ran well.

johndoe0815 3y ago

What a shame :(. I think the only machines I might have access to (again) in the future are also all Explorer Is ("Sperry" OEM-labeled). These are currently 2000km away, but I hope we can move at least one of the machines and get it to work again. Do you think the ROM from the MicroExplorer version of the IC would be useful for the emulator? I think the designation of the chip was different from the one used in the Explorer II, but I suspect the two might still be quite closely related. A MicroExplorer might be a bit easier to find in a working condition... Update (x2, I didn't find the EPROM originally): a MicroExplorer ROM dump is available at bitsavers [1] - 64 kB in size. However, this seems to be a dump of the TMM24512F EPROM on the PCB [2]. The EPROM doesn't seem to contain 68k machine code, which I would have expected in a regular NuBus card ROM, so perhaps this version of the Explorer chip booted from the external PROM? [1] http://www.bitsavers.org/pdf/ti/microexplorer/microexplorer-255_1924-1.rom.BIN http://www.bitsavers.org/pdf/ti/microexplorer/microexplorer-... [2] http://bitsavers.trailing-edge.com/bits/TI/Explorer/pcb_pictures/microExplorer.jpg http://bitsavers.trailing-edge.com/bits/TI/Explorer/pcb_pict...

Suzuran 3y ago
IIMU this is the ROM expected by the Mac Toolbox, but I am not that familiar with the guts of NuBus Macs. I haven't touched Explorer emulation in years, when it dead-ended I moved on to LMI stuff and then gave up on lisp stuff completely when working on the LMI stuff attracted a bunch of outrage.
- pinewurst 3y ago
  What outrage if I can ask? Your LMI emulator (if you're who I think you are) is great!
  - Suzuran 3y ago
    The outrage was primarily centered on what my work wasn't - It wasn't written in (Insert trendy language here) which meant it was an attack on those, it wasn't advancing (Insert cause here) which meant it was an attack on them, it wasn't a CADR, it wasn't Symbolics Genera, it wasn't running on (Insert environment here), and it wasn't living up to the hype surrounding Lisp Machines in general. When I got actual hardware to examine it got a lot worse; nearly all of the feedback I got after that revolved around my being too poor/young/not-famous-youtuber-X/unwilling to part them out. When pictures of my house were posted because I was unwilling to sell a keyboard that was too much. None of this stuff was worth my safety. On top of that, the vast majority of the people who downloaded the emulator didn't even bother to download the disk images or documentation - they just cloned the source repository, did "./configure", and then sent hate mail when it didn't work because the source repository wasn't a release source and required you to do the whole autotools thing. It became a no-win scenario - there was no way I was going to live up to the expectations people had and no way I was ever going to make the gatekeepers happy so I just stopped trying. I moved on to other things that seem to be a lot less controversial and when I do work on something that may be controversial I just don't tell anyone about it.
    - pinewurst 3y ago
      Hell is other people. I thank you for an excellent effort regardless of them. I built it using your very descriptive docs and images and it ran well.