History
The history and stories behind PETSCII¶
PETSCII is a character set designed for the Commodore PET computer. Its creation arose out of necessity rather than foresight, as the system’s hardware limitations — particularly its lack of bitmap graphics — required a different approach to character display. With no ability to address individual pixels, the solution was to create a set of 8x8 blocks, each capable of displaying 256 possible patterns.
Leonard Tramiel, the creator of PETSCII, recalls the pivotal moment in the design process when Chuck Peddle, a key figure in the development of the PET, made a simple but important request: the character set should include the four suits of cards for a Blackjack game. This seemingly modest request helped shape the character set that would become central to the PET's user interface. Beyond this, the character set needed to accommodate the standard alphabetical characters, numbers, and punctuation marks. Leonard was given complete creative freedom to design all other characters in the set.
The design process itself was anything but straightforward. Using graph paper and numerous experiments, Tramiel explored different character arrangements and patterns. The result was the PETSCII character set, which included letters, numbers, punctuation, and a variety of other symbols. However, one notable oversight was the exclusion of lowercase letters. Initially, Chuck Peddle felt they weren’t necessary, but this decision would later be revisited, and lowercase letters were added in subsequent versions of the PET. Had they been considered earlier, Tramiel notes, the character set would likely have been designed differently, with space allocated more efficiently for both uppercase and lowercase letters.
An interesting anecdote from this period involves Chuck Peddle introducing Leonard to Robert Heinlein's science fiction novel The Door into Summer. Chuck envisioned a world where nearly everything had a computer in it, much like the futuristic society depicted in Heinlein's book. This vision profoundly influenced the development of the PET, aiming to create an affordable and accessible personal computer that could bring computing to the masses.
Despite the absence of lowercase characters in the initial design, PETSCII became a foundational element in the Commodore lineup, including the VIC-20 and the Commodore 64. Its simplicity and adaptability made it ideal for systems without bitmap graphics, and it thrived in this context, proving that practical constraints could lead to innovative solutions.
While the team was aware that bitmap graphics were possible, incorporating them into a machine like the PET would have significantly raised its cost. PETSCII’s success, then, was not merely a workaround — it became a defining feature of early home computing, illustrating how ingenuity in the face of technical limitations can shape an enduring legacy.
Leonard Tramiel¶
Leonard Tramiel played a crucial role in shaping the early personal computer and video game industries. From his work on the Commodore PET to his contributions to the Atari ST, TT, and Jaguar, his influence spans decades of innovation. His legacy is undeniable — he is the father of PETSCII, the character set that became an iconic part of the 8-bit computing era. His work laid the foundation for the expressive, blocky graphics and creative text art that defined an entire generation of computing.
Holding a PhD in Physics from Columbia University, Tramiel has since dedicated himself to promoting science and critical thinking, working to improve public understanding of these fields.
Part 1 - Commodore¶
In this part Leonard talks about the creation of PETSCII starting at 30 minuts into the video.