ENGINE.md 3b, the node's side of ruling A (a word's code is the node's, its
accounts the kernel's).
- dict.v4, system.v4: (WORD-DEFINED) ( xt -- ) is run when an entry is
made, (WORD-FORGOTTEN) ( w -- ) when FORGET or COLD removes entries; with
0 there no one is told, as on the hosted product
- test_host_quit.c: a kernel that keeps the list of words and is checked to
hold exactly the node's dictionary after definitions, a vocabulary, an
abandoned definition, FORGET, a refused FORGET and COLD; KERNEL-WORD
called from the prompt and from a definition
Fixed, found while writing that test: since the capsules moved from build
time to boot time (294e6946), what COLD returns to and FORGET protects was
still the nucleus alone, so COLD lost U*, U/MOD and BYE and FORGET U* was
allowed. The boot now seals the system when it has loaded it
(v4_image_seal), and hosted-check checks COLD, the capsule word after it,
the refused FORGET and BYE.
Verified: make -C v4 test passes at both widths (1283 checks in
test_host_quit.c); hosted-check passes on three ISAs; clean qemu with
STARFORTH_V4=1 on amd64, aarch64 and riscv64 passes POST, and COLD, U*
after it, FORGET U* (refused), an unserved kernel word and BYE typed at
each prompt are answered correctly (logs/20261005-193045, -193307, -193636).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
ENGINE.md step 2, the carrier. Ruled 2026-10-05 (V3-PARITY.md 1i), on
DECOMPOSITION.md section 6: a write to a port blocks until the neighbour
reads.
- node: v4_node_port_attach, v4_node_port_served; a store to the port keeps
the value as the request and blocks the node
- exec: a blocked node executes nothing; served, it goes on from the opcode
after the store, in the same instruction word; a fault meanwhile abandons
the rest of the word
- compile.v4: n KERNEL-WORD name makes a word whose body writes n to the
port; its arguments and results are on the data stack
- boot: the kernel's words are made by handing the node text, and requests
are served between the node's opcodes; one no one serves is error 12
- BYE, the first kernel word: hosted it leaves the program, as hosted v3;
on the lone node it is v3's cold restart
- ENGINE.md 3a: multiuser, multitasking, preemptive and cooperative, and
what that asks of the engine
Verified: make -C v4 test passes at both widths, with tests/test_port.c;
hosted-check passes on three ISAs; clean qemu with STARFORTH_V4=1 on amd64,
aarch64 and riscv64 passes POST with the same hashes as hosted, and a
kernel word no one serves and BYE typed at each prompt are answered
(logs/20261005-185506, -185734, -190101; -185234 is an amd64 run in which
those two lines were not typed).
Not done: v3's own C functions serving a node.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A v4 node no longer reads its own command line or prints a prompt. Its
host puts a line of text in the node's input buffer and starts it at
(LINE); the node interprets it and stops at (IDLE), leaving in
(LINE-STATUS) how it ended: completed, an error, or QUIT. The host says
" ok" or " ERROR" and prompts, as the kernel's REPL does for a v3 VM. A
line may be 1024 characters, a block, as v3's. Ruled 2026-10-05
(V3-PARITY.md 1b); design ENGINE.md 3.1.
- quit.v4: (REPL), the node's prompt loop, is gone; (LINE) (IDLE) (DONE)
- image.h/.c: v4_line_begin, v4_line_done, v4_line_status; the node is
idle at switch-on
- boot.c: v4_boot_line, the one loop the hosted binary, the kernel and the
capsule loader hand a line with; the code that took " ok" and the prompt
back out of the node's output is gone
- hosted.c, sk_v4.c: the prompt and the line editing are the host's
- test_host_quit.c: the tests are the node's host; two tests of the old
80-character prompt line now test a whole line, 1024 and 1025 characters
Verified: make -C v4 test passes at both widths; hosted-check passes on
three ISAs; clean qemu with STARFORTH_V4=1 on amd64, aarch64 and riscv64
passes POST (550 of 550) with the same hashes as hosted, and three lines
typed at each bare-metal prompt through the serial port are answered
correctly (logs/20261005-180922, -181152, -181541).
Still the lone node: kernel_main.c starts it before the fleet tables.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The boot is now nucleus, forth79.4th, POST, prompt, on both products.
- forth79.4th: U* and U/MOD, the capsule's first colon definitions. They
are in the FORTH-79 Required Word Set and neither v3 nor v4 had them.
- post79.4th: 550 cases, 126 of the 130 required words. 443 are v3's with
v3's result. The rest follow three rulings (2026-10-05): address-
dependent cases are checked for count, not value; where v3 departs from
FORTH-79 the standard's result is expected; words v3 has no case for get
cases written by hand. v4/tools/post79_rules.py holds each exception
with its reason and docs/v4.0.0/POST79.md lists them all.
- every case starts from an empty stack, DECIMAL and FORTH DEFINITIONS
- the boot requires POST's tally line with fail=0
Verified: tests=550 pass=550 fail=0 and identical PARITY lines on hosted
amd64, aarch64 and riscv64 (make -C v4 hosted-check) and on bare metal,
clean qemu with STARFORTH_V4=1, on the same three (logs/20261005-1619xx,
-1621xx, -1625xx). A U/MOD broken on purpose fails five cases and stops
the boot. make -C v4 test passes.
Not shown: all words but those two are still assembled, so POST has so far
tested the assembled words. Nothing was typed at a bare-metal prompt.
Open: PAD 42 OVER ! faults on v4 (D-1).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
capsules/v4/post79.4th: 537 of v3's POST cases for the FORTH-79 Required
Word Set, each carrying what the hosted v3 binary did with the same line
(error or not, the stack, the length and checksum of what it printed).
Written by v4/tools/mkpost.py. The harness is FORTH-79 plus the two
nucleus hooks. docs/v4.0.0/NUCLEUS.md section 6.
- NODE-ERROR has a FORTH name: how a definition in FORTH raises an error
- the boot passes POST only on seeing its tally line with fail=0
- POST is not in the boot yet (V4_POST_AT_BOOT=0); make -C v4 post runs it
Result: tests=537 pass=439 fail=98. The 98 are not yet sorted into v4
defects and differences needing a ruling; v4/README.md has a first reading.
Verified: make -C v4 test passes; hosted-check passes on three ISAs; clean
qemu with STARFORTH_V4=1 on amd64, aarch64 and riscv64 reaches ok> with the
same hashes as hosted (logs/20261005-1601xx..1604xx). Nothing was typed at
a bare-metal prompt.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
One boot, v4/system/boot.c, for both products: it starts the nucleus image,
finds each capsule in the baked capsule directory, recomputes its hash,
checks its signature, gives its blocks to the node a line at a time, and
prints PARITY:V4_NUCLEUS, PARITY:V4_CAPSULE and PARITY:OK before the prompt.
A line the node does not accept ends the boot with the capsule, block and
line named. docs/v4.0.0/NUCLEUS.md.
- hosted Linux product for amd64, aarch64 and riscv64 (make -C v4 hosted);
make -C v4 hosted-check boots all three and requires identical output
- the kernel's v4 entry (STARFORTH_V4=1) calls the same boot
- capsules/v4/forth79.4th, block 6000: no definitions yet
- mkimage builds the nucleus only; no FORTH source is compiled at build time
- capsule_blocks.c: the Block-header parse, free of any VM, for every loader
Verified: make -C v4 test passes; hosted-check passes on the three ISAs with
the same hashes; the kernel compiles with STARFORTH_V4=1 on the three.
Not verified: no bare-metal boot of v4 has been run.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
