Robert Allan James
ef9806977a
Adds Module 28 (framebuffer_words.c/.h): PLOT ( x y color -- ), FB-WIDTH, FB-HEIGHT -- raw hardware-boundary C primitives, kernel-only, no-op on hosted builds, same pattern as every other module. Adds capsules/fabric.4th (blocks 4900-4902, mkcapsule --lint clean): COS45/Z->DELTA/PROJECT/CART-Y/CART-PLOT -- the 45-degree cavalier orthographic projection and Y-flip, in FORTH per the compose-in-FORTH-first rule (this is policy, not hardware access). Found and fixed a second real bug while live-testing CART-PLOT over the serial socket: defining_word_variable() (defining_words.c) captured vm->here as a VARIABLE's address with no alignment call first, while vm_load_cell/vm_store_cell require 8-byte-aligned addresses. This capsule's VARIABLE ZD landed misaligned (945) purely by chance of what preceded it; other capsules' variables happened to land aligned by luck, not guarantee. Real deviation from FORTH-83/ANS, which specifies VARIABLE reserves an aligned cell. Fixed with vm_align(vm) before capturing addr -- ALIGN already existed as a word but VARIABLE wasn't calling it. Verified end-to-end on amd64 via manual serial injection + QEMU screendump: plotted 4 marker points (origin, +100 X, +100 Y, +50 Z) and confirmed all landed at hand-calculated raster coordinates, including the diagonal up-right shift for the Z-axis point -- the projection math is correct, not just non-crashing. fb/fabric-test-cart-plot.png. 4.3.1's corner diagnostic still renders correctly in the same shot, confirming no regression. All three architectures (amd64/aarch64/riscv64) boot clean to ok> with the DoE completing; dict_hash identical across all three (0xc7f9adf885e306d2), confirming parity is unaffected. FABRIC.md item 4.3.3 marked done with full acceptance evidence.
capsules/
FORTH personality files loaded by the VM at boot. A capsule is an immutable, content-addressed payload; its XXHash64 hash is its identity. Any mutation changes the hash and the birth protocol rejects the image.
Key files
| File | Type | Purpose |
|---|---|---|
init.4th |
(m) MAMA_INIT |
Default Mama VM personality — loaded at LBN 2048 |
ACL.4th |
user | Word-level ACL system; self-activating at boot |
zuse.4th |
user | Bootstrap superuser; loaded by ACL.4th |
doe.4th |
user | DoE workload words (EXEC-DOE) — opt-in |
init-0.4th … init-9.4th |
(p) |
Numbered personality variants |
init-l8-*.4th |
(p) |
L8 Jacquard mode variants (stable/volatile/diverse/temporal/transition/omni) |
hermes/init.4th |
(p) |
Hermes baby VM personality |
artemis/init.4th |
(p) |
Artemis baby VM personality |
Block namespace
Block ranges are shared across all loaded capsules — collisions cause silent word-definition overwrites.
| Range | Owner |
|---|---|
| 2048–2099 | init.4th |
| 2100–2199 | doe.4th |
| 3000–3999 | workload capsules |
| 4000+ | user-defined (ACL.4th, zuse.4th, …) |
Each block is limited to 1024 bytes. Verify with wc -c before committing.
See also
experiments/bare_metal/README.md— DoE protocols and block namespace rulesdocs/03-architecture/word-acl/DESIGN.md— ACL system designtools/mkcapsule.c— assembles capsules intocapsule_generated.c- Project root