StrangeCPU #3. Instruction Slides - The Strangest CPU Yet!
Victor Yurkovsky extends his sliding-window token machine idea to instruction decoding, showing how 8/9-bit tokens can index shared "Blue" memory as 32-bit literals, call targets, or decoded instructions. The approach makes instructions dynamic entries that slide with the window, enabling rare opcodes to be synthesized on demand and reducing fixed opcode bloat. He also covers the 0-bit window (the stack), FPGA BRAM tagging, and the latency trade-offs.
StrangeCPU #2. Sliding Window Token Machines
Victor Yurkovsky walks through a surprising CPU design that expands tiny 8/9-bit tokens into full 32-bit call targets using a sliding-window pointer table. The article explains the red/blue memory model, compilation tradeoffs like table overrun and under-run, literal factoring, FPGA scaling, and even includes an ARM Cortex-M implementation snippet to show how the interpreter works in practice.
StrangeCPU #1. A new CPU
This post rethinks call instructions by factoring call targets out of every callsite and replacing them with tiny tokens. Victor Yurkovsky introduces StrangeCPU, a bytecode CPU that uses 8-bit tokens plus a static sliding-window token table to give byte-long calls full 32-bit reach while dramatically reducing code size. The article includes rationale, tradeoffs, a simple proof-of-concept x86 interpreter, and the basic lookup equation for hardware implementation.
VGA Output in 7 Slices. Really.
Victor Yurkovsky shows how to generate VGA timing on a Xilinx Spartan3 using clever SRL16 tricks to squeeze the generator into just a few slices. By using 32-bit SRLs for line pulses, two mutually prime SRL lengths as a divide-by-99 timebase, and tapped SRLs to combine HSYNC and HBLANK, the approach achieves accurate-enough horizontal and vertical timing with minimal LUT usage.
FPGA Assemblers and Time Machines
Modern FPGA toolchains have turned tinkering into a slog, Victor Yurkovsky recalls the old joy of manual hardware hacking and wants it back. He proposes an assembler-style approach, exemplified by the proposed 'fpgasm', that preserves placement and routing, programs bitstreams in seconds, and makes live probing and rapid iteration practical again. Read this to see why low-level control could revive hands-on FPGA learning.
Tools of the Trade: reading PDFs (and keeping bookmarks)
Victor Yurkovsky recommends MuPDF as a fast, no-frills PDF viewer and shares a tiny C tweak that makes bookmarks persistent and portable. The mod writes a 40-byte file next to each PDF containing ten 4-byte page numbers, so bookmarks follow your files across machines. If you juggle dozens of datasheets and manuals, this keyboard-driven workflow makes reading and navigation dramatically less painful.
FPGA Assemblers and Time Machines
Modern FPGA toolchains have turned tinkering into a slog, Victor Yurkovsky recalls the old joy of manual hardware hacking and wants it back. He proposes an assembler-style approach, exemplified by the proposed 'fpgasm', that preserves placement and routing, programs bitstreams in seconds, and makes live probing and rapid iteration practical again. Read this to see why low-level control could revive hands-on FPGA learning.
PicoBlaze - Program RAM Access for an Interactive Monitor
You can give PicoBlaze a live interactive monitor without reconfiguring the FPGA. Victor Yurkovsky walks through using the BRAM's unused port by replacing the assembler template with a dual-ported RAMB16_S18_S18 and exposing maddr, mfromram, mtoram and mwr ports. The post includes IO decoding and a PicoBlaze assembly test to read, write and increment program memory over a serial link.
StrangeCPU #4. Microcode
Victor Yurkovsky shows how a sliding-window opcode scheme turns tiny 8–9 bit tokens into wide microinstructions on an FPGA, letting you pack rich behavior into compact code. The post explains visibility ranges, instruction-data representation, and a low-cost way to add a Red-program counter so runs of microcode execute efficiently with minimal hardware overhead.
Homebrew CPUs: Color Languages
Victor Yurkovsky proposes turning color from mere syntax highlighting into a semantic tool for a Forth-like CPU, letting color pick which stack an operation touches. He outlines a "Rainbow Forth" where green and blue select two datastacks, red denotes the return stack, gray means use the caller's color, and white is neutral. The post sketches CPU changes, a COLOR register, call encoding and immediate-mode coloring, and teases editor and compiler implications for implementing this idea on a J1-style core.
FPGA Assemblers and Time Machines
Modern FPGA toolchains have turned tinkering into a slog, Victor Yurkovsky recalls the old joy of manual hardware hacking and wants it back. He proposes an assembler-style approach, exemplified by the proposed 'fpgasm', that preserves placement and routing, programs bitstreams in seconds, and makes live probing and rapid iteration practical again. Read this to see why low-level control could revive hands-on FPGA learning.
Tools of the Trade: reading PDFs (and keeping bookmarks)
Victor Yurkovsky recommends MuPDF as a fast, no-frills PDF viewer and shares a tiny C tweak that makes bookmarks persistent and portable. The mod writes a 40-byte file next to each PDF containing ten 4-byte page numbers, so bookmarks follow your files across machines. If you juggle dozens of datasheets and manuals, this keyboard-driven workflow makes reading and navigation dramatically less painful.
Windows XP and Win32 - the Platform of the Future!
Victor Yurkovsky makes the contrarian case that an offline Windows XP VM running Win32 is the most practical platform for modern FPGA development. He explains how Xilinx ISE and related tools often behave far better under XP than on modern Linux distributions, and how VirtualBox fixes USB and GUI headaches. If you maintain FPGA toolchains or write compact C/C++ utilities, this retro setup can save time and frustration.
PicoBlaze - Program RAM Access for an Interactive Monitor
You can give PicoBlaze a live interactive monitor without reconfiguring the FPGA. Victor Yurkovsky walks through using the BRAM's unused port by replacing the assembler template with a dual-ported RAMB16_S18_S18 and exposing maddr, mfromram, mtoram and mwr ports. The post includes IO decoding and a PicoBlaze assembly test to read, write and increment program memory over a serial link.
Homebrew CPUs: Color Languages
Victor Yurkovsky proposes turning color from mere syntax highlighting into a semantic tool for a Forth-like CPU, letting color pick which stack an operation touches. He outlines a "Rainbow Forth" where green and blue select two datastacks, red denotes the return stack, gray means use the caller's color, and white is neutral. The post sketches CPU changes, a COLOR register, call encoding and immediate-mode coloring, and teases editor and compiler implications for implementing this idea on a J1-style core.
