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| -rw-r--r-- | shell/README.md | 61 | ||||
| -rw-r--r-- | shell/evaluate.mu | 2 |
2 files changed, 28 insertions, 35 deletions
diff --git a/shell/README.md b/shell/README.md index e2a38702..12dbdfc4 100644 --- a/shell/README.md +++ b/shell/README.md @@ -1,61 +1,52 @@ ### A prototype shell for the Mu computer -Currently runs a tiny subset of Lisp. Steps to run it from the top-level: +Currently runs a tiny dialect of Lisp. Steps to run it from the top-level: 1. Build it: ```sh $ ./translate shell/*.mu # generates code.img ``` -2. Run it: +You can now already run it: ```sh -$ qemu-system-i386 -m 2G code.img -``` -or: -``` -$ bochs -f bochsrc # _much_ slower -``` - -To save typing in a large s-expression, create a secondary disk for data: -```sh -$ dd if=/dev/zero of=data.img count=20160 +$ qemu-system-i386 code.img ``` -Load an s-expression into it: -```sh -$ echo '(+ 1 1)' |dd of=data.img conv=notrunc -``` +But let's add some more 'meat' to play with. -You can also try one of the files of definitions in this directory (`*.limg`). +2. Create a data disk with a library of functions. ```sh -$ cat data.limg |dd of=data.img conv=notrunc +$ dd if=/dev/zero of=data.img count=20160 +$ cat shell/data.limg |dd of=data.img conv=notrunc ``` -Now run with both code and data disks: +Run with data disk (and 2GB of RAM): ```sh $ qemu-system-i386 -m 2G -hda code.img -hdb data.img ``` -or: -``` -$ bochs -f bochsrc.2disks -``` - -You can type in expressions, hit `ctrl-s` to see their results, and hit -`ctrl-m` to focus on the `...` below and browse how the results were computed. -[Here's a demo.](https://archive.org/details/akkartik-2min-2021-02-24) The -bottom of the screen shows context-dependent keyboard shortcuts (there's no -mouse in the Mu computer at the moment). -*Improvements* +Try typing in some expressions and hitting `ctrl-s` to see their results. +Hit `ctrl-m` to focus on the `...` after a run, and browse how the results +were computed. [Here's a demo.](https://archive.org/details/akkartik-2min-2021-02-24) +The bottom of the screen shows context-dependent keyboard shortcuts. -If your Qemu installation supports them, one of these commandline arguments -may speed up emulation: +3. If your Qemu installation supports them, one of these commandline arguments + may speed up emulation: - `-enable-kvm` - `-accel ___` (run with `-accel help` for a list of available options) -As a complete example, here's the command I typically use on Linux: +If you do this, I recommend also adjusting the `responsiveness` mask in +shell/evaluate.mu, which controls how frequently the fake screen updates. +Smaller values will seem more responsive, larger values will leave more time +to run your programs. I like to see the screen update about once a second. +Some suggested values depending on how fast your Qemu is running: + +- `-enable-kvm` on a T420s running Linux: `0xffff/responsiveness=64k` +- `-accel tcg` on a 2019 Mac: `0xfff/responsiveness=4k` + +Putting it all together, here's the command I typically use on Linux: ``` $ qemu-system-i386 -m 2G -enable-kvm -hda code.img -hdb data.img @@ -63,10 +54,12 @@ $ qemu-system-i386 -m 2G -enable-kvm -hda code.img -hdb data.img *Known issues* +* No mouse support. + * Don't press keys too quickly (such as by holding down a key). The Mu computer will crash (and often Qemu will segfault). -* Mu currently assumes access to 2GB of RAM. To change that, modify the +* Mu currently assumes access to 2GB of RAM. To increase that, modify the definition of `Heap` in 120allocate.subx, and then modify the `-m 2G` argument in the Qemu commands above. Mu currently has no virtual memory. If your Heap is too large for RAM, allocating past the end of RAM diff --git a/shell/evaluate.mu b/shell/evaluate.mu index c1a4ebdc..8574e8a5 100644 --- a/shell/evaluate.mu +++ b/shell/evaluate.mu @@ -27,7 +27,7 @@ fn evaluate _in-ah: (addr handle cell), _out-ah: (addr handle cell), env-h: (han break-if-= increment *call-number var tmp/eax: int <- copy *call-number - tmp <- and 0xffff/responsiveness # every 64k calls to evaluate + tmp <- and 0xf/responsiveness=16 # every 16 calls to evaluate compare tmp, 0 break-if-!= var inner-screen-var/eax: (addr handle cell) <- copy inner-screen-var |