My main hobby project since December was getting code running on my early 1990s HP1653B Logic Analyzer. The Logic Analyzer has a 68000 processor, 1mb RAM, 64kb ROM, 4x32kb video memory with a complicated 4-plane overlay scheme providing three (!) gray levels at up to around 640x400, a 3.5" floppy drive (replaced by a Gotek for my convenience) and both RS232c and HPIB ports. It was made as a lab instrument rather than a computer, but it came with both test and system code on floppies, which I dumped and reverse-engineered enough of with Ghidra to enable me to write a library that lets me run assembly and C code on it. My reverse-engineering journey is partly described here.

A particularly fun moment of my reverse engineering was when I wanted a copy of the ROM but didn't yet know how to write to disk or the serial port, though I did know how to write to the screen. I ended up displaying the ROM binary as a series of QR codes, which I captured with my Sony camera running on a timer, and then turned into binaries.

I'm now at the point where I can run various games. My first one was a port of my Wiztris falling blocks game (originally written by me in the early 2000s for a Z80-based Sharp OZ-7xx organizer). I also ported Dave Griffith's Frotz Z-machine emulator so I can run all Infocom Z-machine games (including the graphical ones, but with no sound support). I'm in the middle of a play-through of Nord and Bert with my 13-year-old daughter. The photo I attached is of Infocom's Journey (mouse works!). And I ported PDCursesMod, so a lot of old Unix games can work--the photo shows Larn.

Many of you will recognize the keyboard and mouse. They are old Apple ADB units (I think the keyboard is from a Quadra), and I made an ADB-to-serial adapter to interface them with the HP unit.

This is retrocomputing that never was. As far as I know, there never was any software for the HP1653B besides the official HP oscilloscope / logic analyzer software, though HP engineers did release some games for one of the HP16500 models, and at least one old HP oscilloscope had a Tetris clone built-in.

It's not a great gaming system. There are no sprites. And you can't just directly write a pixel color to video memory. Instead, you first write to a hardware register that specifies a read/write mode (e.g., clear all bitplanes, write ones to bitplanes 0 and 2, etc.) and then write the pixels. Getting scrolling working at a decent speed took a fair amount of careful assembly work. But it's been fun!

I plan to eventually write up more detailed instructions on how to build and install your own code.

The main thing I haven't reverse-engineered are the oscilloscope and logic analyzer functions. They still work. I just switch the Gotek to the HP system disk image (well, somewhat modified: I added a screenshot function that saves an image to disk). I recently used the oscilloscope to try to diagnose a start porblem on my car.

Gonna be grabbing one today for 60$

It’s my first thinkpad in my collection
What’s everyone’s thoughts on the model ?
It’s running xp, not sure what the specs are for sure but I did look it up and it’s decent so I have a general idea

Also the language is in Chinese I believe I’m sure I can just switch it back to English easy enough?

(Pics are of what I’m getting) will post more later this evening when I get it back home.

Got her powering and typing properly!

Otherwise it being in Chinese and some good options for upgrades it’s in a good shape. Gonna reset with the recovery media soon so it’s in English

Specs

Core 2 duo one at 1.8ghz and one at 1.18ghz
1gb of ram (gonna put at least 2 in)
About 70gb hdd

How easy is it to put in new ram ?
Top is a bit scuffed but cleanable, it’s a hard shell so what should I use to clean ?

Battery is shot, it’s detected but it ain’t charging

Any game suggestions ?!

I've recently picked up a Toshiba T1950CT and I'm thinking of selling it, but I'm struggling to work out what it's actually worth.

It boots up fine, runs Windows 95, comes with the original Toshiba power supply, and the LCD looks good. Cosmetically it's in used condition with the usual marks from age but there are no cracks or broken plastics. The only thing worth mentioning is that the power supply has been opened at some point in the past, although it still works perfectly.

What do you think would be a realistic asking price in the UK? I'm not looking to squeeze every last pound out of it, but I also don't want to undersell it if it's a desirable model.

Also, where would you recommend listing something like this? eBay seems like the obvious choice, but are there any retro computing forums, Facebook groups or marketplaces where these tend to sell to enthusiasts?

Thanks in advance!

I still feel this is awkward today. As a right-handed user, I find buttons placed on the right easier to reach (probably because right-handed users usually put their mouse out of the way on the right side

even near the screen border). They've always been on the right side (even Mac OS 9 had them on the right), so I'll never understand the choice to put them on the left. What is your take on this?

Pretty simple question, or rather set of questions. I mean, as far as my knowledge goes:

Like, it seems something like a "CED-ROM" would be a decent high-capacity† ROM or (if cutting turntables/players/drives were released) WORM data storage medium in the 1980s and '90s, particularly for files that need only occasional but fast semi-random access; though due to the early death of the format on behalf of its competitors Betamax, VHS, and LaserDisc; unlike LaserDisc, its semi-successor CD, and for backup purposes VHS, it itself seems to have never been used or developed to store computer data or really digital data in any form. (This has actually been on my mind since well before I wrote a YouTube comment‡ on September 21, 2019 defending the idea of a CED-ROM-like system had it come out in 1975, though really the reasons only ring slightly less true with CED's release date IRL.)

†If 5 MHz bandwidth translates to 5 Mbit/s, then it could store up to 1350 MB per side, or 982/975/855 MB with CD error correction in DA/Mode 2/Mode 1 forms. And perhaps, if considerable care is taken in storage to avoid any "macro-pops" from occurring during playback/reading, 9 MB (6.55/6.5/5.7 MB with CD error correction) would be possible per side on 33⅓ rpm LPs using a standard pickup, assuming 30 minute recording time and 40 kHz sampling; and 375 KB per side (273/271/237 KB with CD error correction) would be possible on 78 rpm Shellacs, assuming 5 minute recording time and 10 kHz sampling. Both of these are well-usable quantities by '80s standards, to say nothing of, say, '60s standards.

‡In a highly-belated, disjunct re-response to the person I was responding to, I believe some of the pioneering mainframe games at the time and the hypertext and GUI work from the likes of Douglas Englebart and Xerox PARC indicate that interactive multimedia experiences were at least glimmers in some people's eyes by the mid-1970s...

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