Category Archives: Objects

4+1 Multi-pens: A Survey

My increasingly absurd 4+1 multi-pen collection, left to right:
Dr.Grip 4+1, Uni Style Fit Meister 5, Zebra Clip-On Multi, Zebra Sarasa, Hi-Tec-C Coleto 5, Uniball Jetstream 4&1

I’m a little obsessive about my everyday objects, in that stereotypical engineer “determine an optimal solution and stick to it” sort of way. For about a decade I carried a little (handmade, periodically replaced) sleeve with a Bic MatiC grip 0.7 pencil and Black, Blue, and Red Uniball Vision Elite pens in 0.5mm (plus a chapstick and flash drive).

Trusty old Pocket Organizer

That utensil set is for a note-taking system where my own work and other temporary or uncertain things are in pencil, notes and other reference material are in black, provided examples and commentary are in blue, and corrections and attention points are in red. Diagrams are multi-colored for clarity.

I have a ritualized paper-handling (I carry a clipfolio and periodically file into binders), page-labeling (Top right,Topic/Date/Sequence Number), bullet hierarchy (A little drift over the years, but mostly ⊕ > • > ⁃) , and archiving (Rarely-used topics get twist-ties through the binding holes and stored in boxes) system that I’ve been using for decades at this point.

Since 2019 I’m primarily teaching labs, so in addition to my own note-taking I do a lot of drawing examples and correcting solutions where a variety of colors is useful, and I kept wanting more than the 3+1. Carrying around a whole stack of writing utensils seemed unreasonable… until I found a 4+1 multi pen I got as conference swag, and it set me off on an expedition.

I tried my conference-swag Zebra Clip-On Multi for a few weeks, liked it for the most part but missed the writing quality of my Vision Elites, got slightly obsessed, and bought examples of most of the 4+1 pen bodies on the market to compare. Then I used each for a week during the Fall ’19 semester to get a feel for them.

TL;DR
My current favorite 4+1 multi-pen body is the Pilot Dr. Grip 4+1, loaded with Uniball Signo D1 refills and Pentel Ain Stein HB lead. It’s only major weakness is the covered tiny eraser.

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3C589 PCMCIA Network Cards and OpenStep

Google being displayed in OmniWeb 3.1 on OpenStep 4.2.  In 2021.

After my last post about OpenStep 4.2 on my ThinkPad 560E, one of the dangling TODO items was figuring out why the network setup that was made of all known-working parts didn’t work. I’ve now figured it out.

[TL:DR: The OpenStep 4.2 Etherlink III driver does a bad job with PnP and Media Autodetect on 3C589 cards. To make one work you will probably need to use 3Com’s DOS configuration utility to configure the EEPROM in the card.]

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ThinkPad 560E + OpenStep 4.2

Photo of Thinkpad 560E System, running OpenStep 4.2
One Fancy Commercial Unix Portable Battlestation, ca. 1997

I’ve now tried out a few of the things I bought the Thinkpad 506E I posted about a while ago to try, and there are some interesting notes to share before the semester gets underway and I run out of energy again.

I decided amid some resultant discussions (Hi HN!) from my last post on this machine to give myself a conduct of not physically opening the hardware while I play with it, unless the HDD dies or the like. Doing so is making me exercise some long-dormant skills, which has been extremely fun.

So far I’ve amassed a pile of compatible accessories, booted into NetBSD and imaged off the original HDD contents, installed OpenStep 4.2, fixed the drivers, updated to Patch4, and very briefly taken it online before an irritating networking problem arose. I’ve also run into a problem getting RhapsodyDR2 on, which will likely be the next time-sink.

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Router Replacement: Asus RT-ACRH13

RT-ACRH13 being flashed.

I’ve been running a TP-Link Archer C7 flashed with OpenWRT at home since early 2016 (and a TP-Link 1043ND with OpenWRT for years before that), but since I moved into my current place over the summer it has been falling over every couple weeks. It hasn’t been logging anything (I have a flash drive mounted that it persistent logs to) but goes down until hard reset, most likely just because of the load of two heavy stream/video-conference/file-sync users (…and probably not because of my kitten chewing on the antennas. Probably.) Rather than updating/diagnosing I decided that was a good excuse for a new faster router.

TL;DR: The Asus RT-ACRH13 is an excellent current-production OpenWRT host for ~$65 with only minor install challenges, and represents a significant upgrade over the Archer C7.

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EBAZ4205 Surplus ZYNQ Board

EBAZ4205 FPGA board connected to PSU and serial adapter.

A not long ago there was some noise in places I follow about Zynq FPGA boards surplussed from their role as controllers in retired cryptocurrency mining rigs, for way less than the price of even the bare FPGA SoC. I impulse bought one EBAZ4205 from “College Shop Store” on Aliexpress for $19.08 shipped to try them out, since it seems to to be the most common and documented flavor, and it showed up yesterday. Short version: they look awesome for the price.

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A Quick and Dirty Workbench

New workbench with powered CNC router system.

Since I moved in to my current house in May, I’ve been thinking about putting a (n additional) workbench in front of the inscrutable 7ft wide projection screen (?) thing some previous tenant built in the basement. I sketched out what I wanted early summer, and drew a proper design and cut-list in September – but by then the grueling part of the break-less fall semester had started, so it never got to the top of my list. This week I finally got around to picking up the parts and building it. This has been a rate-limiting step for other projects, since it was partly needed as a home for my CNC router.

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Interesting (but disappointing) Mini Buck Boards

I needed some cheap little vregs recently and had run out of and/or lost all of my useful-value 780x linear parts, so I decided to look at what people in this century use. 

I found some little buck boards roughly the size of a TO-220 package that looked exciting. These particular ones are QSKJ Mini DC-DC Buck Step Down Module model “QS-1205CME-3A”, Vendor page here, mine were 5pcs/$9 from Amazon.

Upon analysis they have serious issues with regulating under load, so the hunt for something decent continues, but the form-factor and advertised feature set are really compelling.

Pros:

  • High-efficiency high-frequency synchronous buck instead of a linear heater^H^H regulator.
  • Solder-jumpers for 1.8,2.5,3.3,5,9,12V or a default (fiddly, tiny) adjustment pot output so you only have to stock one device – one easy-to-cut trace to disable adjustable mode.
  • Tolerates 4.5-24V input as long as out < in or so.
  • Good stability to input voltage variation.
  • ~0.25V drop-out.
  • Does appear to have a cutoff for over-current.
  • No perceptible ripple under various load conditions.

Cons:

  • Voltage regulation manages maybe 600mA at 5V before droop becomes unacceptable (<4.8v).

…and that makes it basically useless for most applications. Test data below the fold.

Maybe it could be resolved with appropriate external capacitors and/or offsetting the adjustable to regulate right at a known load or something, but not being drop-in really reduces their charm.

Anyone know of a similar offering that doesn’t suck at output regulation?
(Rel: Anyone know if any of the low-end electronic loads are worthwhile? I’m not looking to spend real-lab-instrument money, but it’s come up often enough lately that I want to be able to dissipate a couple 10s of Watts through a at least stepwise-controllable resistive load).

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Macintosh SE Health Check

I had my dear old Macintosh SE out for a health check as I slowly extract my vintage computer collection from the (unconditioned) place I’ve been keeping it at my parents house to the basement of the place I’m renting. It had a couple interesting findings that seem worth putting online, including another floppy drive rebuild and a slightly elaborate fan replacement.

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Why did a Banggood package I ordered on March 26 just appear in Bahrain on July 5, the same day it finally showed “Shipment picked up?” Did it just get packed into a container and loaded on whatever outgoing vessel … Continue reading

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Anycubic Linear Kossel: Unofficial Owner’s Guide

Anycubic Kossel on its stand

I’ve been working with a number of Anycubic Linear Kossel / Kossel Plus (whatever branding they’re using when you look) 3D printers for the last couple months, including one I bought personally. While I’m overall extremely pleased with them, there are a whole bunch of notes, fixes, and improvements I feel like should be collected somewhere.

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