rsbohn

The UPVERB Saga: Four Bugs in Twelve Lines of Nova Assembly

Or: how a simple "make it case-insensitive" turned into a masterclass in why assembly is hard.

The Setup

I'm working on CVIT, a terminal game running on a DG Nova emulated in SIMH (and on Dusky, a custom Nova emulator in C#). The command interpreter lives in cvit-command.asm — about 700 lines of Nova assembly. Commands like TYPE, CAT, and STA are dispatched by comparing the input buffer against uppercase constants.

The task seemed trivial: make the commands case-insensitive. Type type hello instead of TYPE HELLO. How hard could it be?

rsbohn

# APPS/UTIL/STORAGE
# List mounted filesystems grouped by filesystem type.

if ! command -v findmnt >/dev/null 2>&1; then
  echo "findmnt not found"
  exit 1
fi

findmnt -r -n -o FSTYPE,SOURCE,TARGET,OPTIONS |
sort -k1,1 -k3,3 |

rsbohn

#!/usr/bin/env python3
import curses
import time

# Simple terminal animation: a tiny guy slides in, hops, then battles birds.
# Press 'q' to quit early.

TINY_GUY_STAND = [
    " o ",
    "/|\\",

rsbohn

2026-03-03 — Wiggles

Goal

Explore zero-shot image classification using CLIP embeddings already stored in the artifacts llm collection (125 images), then build an interactive visualization to explore the results.

What We Learned

rsbohn

****
** factor.asm -- factor 32 bit numbers
****
    AORG >0000
    DATA WPA    ; WP
    DATA START  ; PC

    AORG >1000  ; workspaces
WPA BSS >20
WPB BSS >20

rsbohn

****
** dullboy.asm -- runs on TMS9900 computer
****
** MMIO UART
THRE    EQU >F000   ; UART transmit empty
THRL    EQU >F002   ; UART transmit load

** Reset Vector
    AORG >0000
    DATA >1000

rsbohn

#!/usr/bin/env python3
"""Create a TU56 DECtape image with place names for a game."""

import struct
import sys

# TC08 constants
WORDS_PER_BLOCK = 129
DATA_WORDS_PER_BLOCK = 128
BLOCKS = 0o100  # 64 decimal blocks

rsbohn

<!DOCTYPE html>
<html>
<head>
  <title>How Soon Is Now? - Interactive Synth</title>
  <style>
    body { font-family: sans-serif; background-color: #282828; color: #e0e0e0; display: flex; flex-direction: column; align-items: center; }
    h1 { font-weight: 300; }
    #controls { background-color: #3c3c3c; border-radius: 8px; padding: 20px; margin: 20px; width: 350px; }
    .control-group { display: flex; justify-content: space-between; align-items: center; margin-bottom: 15px; }
    label { font-size: 1em; }

rsbohn

GtPlotterScatterFocusPointHandler subclass: #DexPointEventHandler
	instanceVariableNames: 'chart'
	classVariableNames: ''
	package: 'uncertain'!

!DexPointEventHandler methodsFor: 'accessing' stamp: 'Dexter 7/18/2024 05:30'!
chart: theChart
	chart := theChart! !

!DexPointEventHandler methodsFor: 'accessing' stamp: 'Dexter 7/18/2024 06:11'!

rsbohn

Object subclass: #AnthropicClaude
	instanceVariableNames: ''
	classVariableNames: 'ApplicationKey'
	package: 'LLM-AnthropicClaude'!

!AnthropicClaude methodsFor: 'accessing' stamp: 'GlamorousAuthor 6/8/2024 12:25'!
invoke: userPrompt system: systemPrompt
	| client payload response |
	payload := {#model -> 'claude-3-haiku-20240307'.
			#max_tokens -> 1536.