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Course: The TRI-27 ternary computer -- trits to a CPU on an FPGA (9x3, hardware track) #1486
Description
Parent epic: #1476
Course id: ternary-computer
Audience: hardware engineers (RTL / FPGA / ASIC).
Prerequisites: Course 0 (t27 basics); Course 1 module numbers.
Why this course
Planned in the course roadmap (ternary-computer) and the most original material the project owns: 18 ISA specs and 64 ternary specs describe a complete balanced-ternary machine. Building a CPU is the classic capstone of computer-architecture education; building a ternary one is unique.
What already exists in the repo (grounding)
isa/(18):ternary_encoding,ternary_gates,ternary_bitwise,ternary_arithmetic,ternary_shift,registers,ternary_memory,tri27_machine(93 test failures in the browser runner today),tri27_bytecode,ternary_control_flow, data-structure specsternary/:packed_trit,ternary_xor,ternary_full_adder,ternary_ripple_adder,hybrid_arithmetic,clocked_counterfpga/ternary_isa.t27,fpga/assembler.t27,fpga/linker.t27,fpga/bootrom.t27,fpga/simulator.t27,fpga/ternary_link.t27+ testbenches
Decomposition: 9 modules x 3 lessons
Module 1 -- trits: a digit with three values
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 1 | balanced-ternary |
-1, 0, +1 and why negation is free | isa/ternary_encoding.t27 |
trit counter |
| 2 | encoding-trits-in-bits |
2 bits per trit and the wasted state | ternary/packed_trit.t27 |
packing density chart |
| 3 | radix-economy |
radix economy: why 3 is close to e | isa/ternary_encoding.t27 |
cost curve |
Module 2 -- gates: ternary logic
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 4 | min-max-not |
ternary AND/OR/NOT as min/max/negate | isa/ternary_gates.t27 |
truth-table explorer |
| 5 | ternary-xor |
sum mod 3 | ternary/ternary_xor.t27 |
truth table |
| 6 | gates-in-luts |
what a ternary gate costs in LUT6 | isa/ternary_gates.t27 |
LUT count from a yosys run |
Module 3 -- arithmetic: adding without a sign bit
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 7 | full-adder |
the ternary full adder | ternary/ternary_full_adder.t27 |
adder stepper |
| 8 | ripple-adder |
ripple carry over trits | ternary/ternary_ripple_adder.t27 |
carry ripple animation |
| 9 | shift-and-multiply |
shift by a trit = multiply by 3 | isa/ternary_shift.t27 |
shift visual |
Module 4 -- state: registers and memory
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 10 | register-file |
the TRI-27 register file | isa/registers.t27 |
register viewer |
| 11 | ternary-memory |
addressing in trits | isa/ternary_memory.t27 |
memory map |
| 12 | clocked-counter |
the first clocked ternary circuit | ternary/clocked_counter.t27 |
counter waves |
Module 5 -- the-isa: an instruction set
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 13 | instruction-formats |
opcodes and operand fields | isa/tri27_machine.t27 |
instruction decoder |
| 14 | the-machine |
fetch, decode, execute | isa/tri27_machine.t27 |
CPU stepper |
| 15 | isa-on-fpga |
the ISA mapped to hardware | fpga/ternary_isa.t27 |
datapath diagram |
Module 6 -- toolchain: from text to code
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 16 | bytecode |
the bytecode format | isa/tri27_bytecode.t27 |
byte inspector |
| 17 | assembler |
two-pass assembler, labels | fpga/assembler.t27 |
assembler playground |
| 18 | linker |
sections, relocation | fpga/linker.t27 |
link map |
Module 7 -- programs: making it do something
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 19 | control-flow |
branches and loops in trits | isa/ternary_control_flow.t27 |
program trace |
| 20 | boot-rom |
how the machine starts | fpga/bootrom.t27 |
boot sequence |
| 21 | simulator |
the reference simulator | fpga/simulator.t27 |
simulator trace |
Module 8 -- algorithms: ternary data structures
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 22 | sorting |
sorting on a ternary machine | isa/ternary_sorting.t27 |
sort race |
| 23 | search-and-hash |
search and hashing in trits | isa/ternary_hash.t27 |
hash spread |
| 24 | trees |
ternary trees | isa/ternary_tree.t27 |
tree view |
Module 9 -- on-the-chip: the computer on real hardware
| # | Lesson id | What the reader learns | Spec | Widget idea |
|---|---|---|---|---|
| 25 | hybrid-arithmetic |
binary/ternary hybrid datapaths | ternary/hybrid_arithmetic.t27 |
cost comparison |
| 26 | ternary-link |
talking to the host | fpga/ternary_link.t27 |
link trace |
| 27 | capstone |
run a program on TRI-27 on the board | isa/tri27_machine.t27 |
board run receipt |
Honesty notes and traps
- Honest framing: ternary on a binary FPGA is emulated with 2-bit trits; the course must show the cost, not claim an efficiency win the data does not support.
tri27_machine.t27cannot run in the browser yet (93 failures); blocked by the runner issue.
Acceptance criteria
-
specs/course/<id>.t27+<id>-ru.t27exist, registered inspecs/course/courses.t27, built bycourse-from-spec.mjs(recipe:specs/course_recipe/course-27.t27). - Exactly 9 modules x 3 lessons = 27 lessons; every lesson names one widget and one spec.
- Every lesson spec compiles AND its
testblocks pass in the reader's browser (blocked by the browser-runner issue), or the lesson says plainly that it is a recordedtricast and links the recording. - Every number on a page comes from real tool output named in the widget's
DATA_SOURCES(yosys / nextpnr / board run / spec test). No invented figures. - Board named on every hardware page (Wukong
xc7a200tfgg676vs AX7203xc7a200tfbg484vs Arty A7 / XC7A100T). - Black-and-white share cards and SEO pages generated for all 27 lessons (EN + RU).
- The course PR carries a blog post: EN
body+ RUruBody. - Lessons that need a spec that does not exist yet are listed as sub-tasks (spec first in
gHashTag/t27, then copied here).
Blocked by: #1477 (browser test runner) for every lesson whose spec uses calls, locals or struct fields in tests.
Activity