Some new additions to the modem teardown album: US Robotics Courier 9600 HST (manual, photos), “widebody” FCC ID CJE794FAST. This is similar to the 14400 HST I already have in the album, except this one takes 16 VAC power with a male DIN-5 plug. A PDF of the manual already is online at vtda.org, […]
Category Archive for 'retro'
Retro case MHz LED readout setup
Posted in retro on Jun 5th, 2025
Back in the day when we had x86 IBM PC systems with “turbo mode”, which was really a reverse euphemism for being able to slow down the CPU clock for older applications, snazzier cases had a LED readout on the front to show the current MHz instead of/in addition to just a plain turbo LED. […]
Vintage Diamond video RAM upgrade-a-thon
Posted in retro on Jun 3rd, 2025
At the recent Electronics Flea Market somebody had a stack of Diamond ISA and VESA Local Bus video cards for sale. Which is funny because I had just been looking to maybe take the splurge and try to find a VLB card with an Tseng ET4000/W32 to put into my 486. I currently have a […]
Dallas RTC chip replace-a-thon
Posted in retro on Jun 2nd, 2025
I finally reached the point in my vintage gear lifestyle where I needed to replace old Dallas realtime clock chips that have dead batteries. I opted to try to find replacement chips, taking a gamble with “new old stock” units, instead of trying to grind down the side of the chip casing to attach leads […]
Finding old ftp.usr.com US Robotics support files
Posted in retro on May 19th, 2025
The Internet Archive is invaluable when working with old hardware or software when you need to go look at old version of a website to find manuals, drivers, or general info. Unfortunately a great number of files lived on FTP servers because the web wasn’t really up to hosting them in the 1990s, and many […]
TL;DR: I complain about my failings and show off pictures and log files. Later some gradual understanding of ISDN and why this probably won’t work with my particular version of the Courier I-modem with a U interface. Turns out U is electronically incompatible with S/T. In my telcom fiddlings to get a 56k dial-up modem […]
TL;DR: replaced LH1056 solid state relay / optocoupler at U3 One of the USR Courier HST modems I purchased recently had a peculiar problem that if I plugged the phone line into the “wall” jack of the modem it returned NO DIALTONE when I tried to dial something, yet I was able to dial something […]
US Robotics Courier I-Modem power adapter substitute
Posted in retro on Apr 29th, 2025
TL;DR: Original US Robotics I-modem power adapter is extremely rare. I cut mine open to document it. Original adapter provides 20 V AC (1500 mA capacity) across pins 3-4 of mini-DIN connector, no other voltages. Substituting a $15 24 V DC power adapter seems to work just fine. The US Robotics Courier I-Modem seems to […]
I picked up a couple of “widebody” USR Courier HST modems and have been working through documenting power adapters for them and sorting out what goes with what. I figured out almost all Courier and HST models have different power supplies and voltage requirements. I’ve been tracking down manuals and cross-referencing the FCC IDs in […]
A story of doing ISP customer billing
Posted in retro, Uncategorized on Mar 31st, 2025
A collection of stories of evolution, follies, starting from scratch, and what not to do. When I started my ISP back in the summer of 1996, how to bill customers and collect money from them was an afterthought. I started with nothing, not even a database, and not realizing what a vital chore it would […]
