Proudly announcing version 1.0 of the PET 2001 online emulator.
Yet another PET 2001 related title illustration.
Recently, I’ve been posting on Commodore BASIC and more specifically about the PET 2001 quite a bit. While not the sole reason, this was partly because I was adding a few features to the PET 2001 online emulator behind the scenes. I even endeavored into a major reorganization of some of the source code in order to facilitate this and future work. And, last but not least, there’s now even a suitable help file / documentation. — Reason enough to promote the emulator from its previous beta state to version 1.0!
A closer look at the logic behind Commodore ASCII, AKA “PETSCII”, and the PET 2001.
Investigations into a somewhat mysterious character code.
The flavor of ASCII used by the Commodore 8 bit computers, commonly known as PETSCII, is asking for a bit of an explanation. PETSCII is a peculiar beast, close to ASCII, but not quite, somewhat compatible, but not really, there are duplicate ranges of characters all over the place, and the special characters are lacking any recognizable order… — But look at all these these funny graphics characters!
In order to make sense of this and how the character set is organized, it may be helpful to have a closer look at it with a particular focus on the PET 2001. At least, this is the very machine, this character set originated on and for which it was designed for, with no idea yet that this may become the ancestor of a succesful line of home computers. Here, we may discover logic, in what must remain a puzzling enigma on the more popular and better known machines that followed, like the C64.
Learning from history: How to keep calm while panicking and carry on with face masks
Wear a mask or go to jail — California, 1918. (Raymond Coyne, 1918-11-03)
Influenza and influencers, and a friendly customer information from 1918. Apparently, it’s not the first time, we’re facing an epidemic. Some prefer doing so while wearing a face mask, others may prefer desinfectants. Arguably, masks make the better photographs.
String exploits and a reasonably paced video game in just 10 lines of Commodore BASIC.
Yee-haw! — A canyon to ride by just 10 lines of BASIC!
In continuation of and as a finale to our mini series on the internal representations of Commodore BASIC, we’ll now put some of our findings to use, especially some possible exploits of string variables.
What we’re going to do, is a classic canyon run game, where a single player rides/flies/drives/navigates a procedurally generated canyon down from the top, trying to progress as far and deeply into the winding depths as possible while avoiding the walls of the canyon. And we’re going to implement it in just 10 lines of BASIC, which puts some serious constraints on our solution. As do some of the intricacies of the PET 2001. Especially, we’ll have to avoid any direct access to the video memory (as in PEEKs and POKEs), meaning, we’ll do it all by print statements. So we’ll have to consult our bag of tricks — and come up with some exploits of the string mechanism.
Spoiler alert: It will be about fast partial strings and fast FIFO queues, while avoiding garbage collection.
Investigations into the memory utilization of Commodore BASIC (PET 2001, VIC-20, C64)
The astounding intricacies of Commodore BASIC variables.
In continuation of our last episode, we return to our investigations into Commodore BASIC memory representations. This time, it’s about variables, arrays, and, especially, strings.
How to thoroughly renumber Commodore BASIC programs (PET 2001, VIC-20, C64)
The curious wonders of Commodore BASIC renumbering.
Renumbering a is popular beginner’s sport for those who dare to venture into the mythical realms of intricacy, which the BASIC interpreter and its storage formats provide. Since it is also a useful utility, there are numerous programs for this, especially it’s a favorite example in the intructory sections of machine language guides. However, as always, there’s an easy way and a thorough one. And we’ll see soon, why this may be.
I am happy to announce a long planned for update to meSpeak.js, an open source TTS for the Web in JavaScript. This version brings some major update (and some minor discontinuities in API as well.) In a nutshell, meSpeak.js is the open source eSpeak program crosscompiled to JS using Emscripten (a minimal POSIX runtime to run LLVM compiler output in JS) running in the browser with some additional API glued on top. MeSpeak.js is based on speak.js, which has been an early demo application for Emscripten, but differs somewhat in architecture and features (like access to the entirety of eSpeak options, facilities for export and/or buffering of audio data, a built-in audio playback API, modular voice and language descriptions, etc) and also in compatibility.
Affordable computing by rotating bits at 3700 rpm.
In July 1956, when IBM was still considering its answer (which was to become the IBM 1401) to the French challenge that was the Bull Gamma 3 (1952), then posing a serious threat to IBM’s monopolic line-up of punched card appliances, Librazette, Librascope’s employees’ and PR gazette, proudly announced that the company’s new LGP-30 computer had been promoted to production.
The computer had been developed by Stan Frankel as the MINAC at CalTech in 1954 and Librascope had bought Frankel’s design (apparently in the same year), releasing it as the LGP-30 in 1956. (…)
LGP-30 sales brochure, Royal McBee Corporation, 1956.
The computer generally known as the Royal McBee LGP-30 was a desk-sized appliance and weighed in at about 800 pounds (360 kg). It came with a Flexowriter-style console typewriter and consisted internally of just 113 vaccum tubes, 1,450 solid state diodes, and a magnetic drum for memory (4K of 31-bits words) and 3 registers. It plugged into an ordinary wall socket, from which the combined circuitry drew up to 1500 Watts. All this could be yours for just US$ 47,000 ($433,000 in 2018), which was actually the first viable option for small-to-medium scale computing.
