Norbert Landsteiner
@masswerk.at
Mostly retro and vintage computing content, I guess.
www.masswerk.at
www.masswerk.at
PS: Of course the flags seem to be added manually, as well, but still follow in their distribution the rule of alotting detail to a central (or topical) mass, regardless of function.
Compare the image below.
Yet, while being pushed to the periphery, these alotted elements carry the very maessage.
Compare the image below.
Yet, while being pushed to the periphery, these alotted elements carry the very maessage.
January 10, 2026 at 1:16 PM
PS: Of course the flags seem to be added manually, as well, but still follow in their distribution the rule of alotting detail to a central (or topical) mass, regardless of function.
Compare the image below.
Yet, while being pushed to the periphery, these alotted elements carry the very maessage.
Compare the image below.
Yet, while being pushed to the periphery, these alotted elements carry the very maessage.
December 25, 2025 at 12:45 PM
December 24, 2025 at 10:11 AM
We also see the basic conundrum of this approach: there's an internal encoding, using a half-byte bit vector to represent a quarter-blocks character (see image).
If we look up the character value in video RAM, this spans over values from 0x20 to 0xFF and we need a 256 byte lookup table.
1/2
If we look up the character value in video RAM, this spans over values from 0x20 to 0xFF and we need a 256 byte lookup table.
1/2
December 22, 2025 at 11:20 AM
We also see the basic conundrum of this approach: there's an internal encoding, using a half-byte bit vector to represent a quarter-blocks character (see image).
If we look up the character value in video RAM, this spans over values from 0x20 to 0xFF and we need a 256 byte lookup table.
1/2
If we look up the character value in video RAM, this spans over values from 0x20 to 0xFF and we need a 256 byte lookup table.
1/2
BTW, the forest in its natural habitat (yes, it's JS):
December 22, 2025 at 10:54 AM
BTW, the forest in its natural habitat (yes, it's JS):
X-Mas Quest:
Can I do a 6502 X-mas themed game for the Commodore PET in a single day?
Progress so far…
Can I do a 6502 X-mas themed game for the Commodore PET in a single day?
Progress so far…
December 21, 2025 at 10:00 AM
X-Mas Quest:
Can I do a 6502 X-mas themed game for the Commodore PET in a single day?
Progress so far…
Can I do a 6502 X-mas themed game for the Commodore PET in a single day?
Progress so far…
I think, I finally managed to capture "PET Invaders" with sound.
Grab it here:
masswerk.itch.io/pet-invaders
#petscii #commodore #8bit #mos6502
Grab it here:
masswerk.itch.io/pet-invaders
#petscii #commodore #8bit #mos6502
December 19, 2025 at 3:27 AM
I think, I finally managed to capture "PET Invaders" with sound.
Grab it here:
masswerk.itch.io/pet-invaders
#petscii #commodore #8bit #mos6502
Grab it here:
masswerk.itch.io/pet-invaders
#petscii #commodore #8bit #mos6502
December 18, 2025 at 8:02 PM
Here's a short example.
Mind how this supports indentation and how we may use 'LOG' as a procedure name, while this also a standard BASIC token (for the function "LOG()").
Mind how this supports indentation and how we may use 'LOG' as a procedure name, while this also a standard BASIC token (for the function "LOG()").
December 17, 2025 at 4:25 PM
Here's a short example.
Mind how this supports indentation and how we may use 'LOG' as a procedure name, while this also a standard BASIC token (for the function "LOG()").
Mind how this supports indentation and how we may use 'LOG' as a procedure name, while this also a standard BASIC token (for the function "LOG()").
Time to get ready for that time of the year: updated "Season's Greetings" available for Commodore PET (40 cols).
Get it here:
masswerk.at/pet/prgs/#se...
Get it here:
masswerk.at/pet/prgs/#se...
December 15, 2025 at 5:37 PM
Time to get ready for that time of the year: updated "Season's Greetings" available for Commodore PET (40 cols).
Get it here:
masswerk.at/pet/prgs/#se...
Get it here:
masswerk.at/pet/prgs/#se...
Continuing a theme on EOR operations for managing sprite state, as it previously arose in thread by @0xc0de.bsky.social :
This is how "PET Invaders" runs at 60 fps (and also, why it doesn't fit into just 8K of memory): there are lots of pre-shifted graphics, and a table with references to them:
This is how "PET Invaders" runs at 60 fps (and also, why it doesn't fit into just 8K of memory): there are lots of pre-shifted graphics, and a table with references to them:
December 5, 2025 at 12:47 PM
Continuing a theme on EOR operations for managing sprite state, as it previously arose in thread by @0xc0de.bsky.social :
This is how "PET Invaders" runs at 60 fps (and also, why it doesn't fit into just 8K of memory): there are lots of pre-shifted graphics, and a table with references to them:
This is how "PET Invaders" runs at 60 fps (and also, why it doesn't fit into just 8K of memory): there are lots of pre-shifted graphics, and a table with references to them:
Ha-ha!
The PET 2001 emulator now exports SVG images, rendered from the current state of the video memory and the character ROM in use. And, yes, these are optimized paths.
masswerk.at/pet
(SVG export is available via the screen's context menu.)
The PET 2001 emulator now exports SVG images, rendered from the current state of the video memory and the character ROM in use. And, yes, these are optimized paths.
masswerk.at/pet
(SVG export is available via the screen's context menu.)
December 4, 2025 at 1:43 AM
Ha-ha!
The PET 2001 emulator now exports SVG images, rendered from the current state of the video memory and the character ROM in use. And, yes, these are optimized paths.
masswerk.at/pet
(SVG export is available via the screen's context menu.)
The PET 2001 emulator now exports SVG images, rendered from the current state of the video memory and the character ROM in use. And, yes, these are optimized paths.
masswerk.at/pet
(SVG export is available via the screen's context menu.)
Back in 1998 talking toys like the Furby could run on a Sunplus SPC81A microcontroller, a cut-down 6502 without the Y-register.
Modern talking toys, like the "Large Language Furbies" of our times, are threatening to swallow the entire electronic manufacturing capacity and eventually the Planet.
Modern talking toys, like the "Large Language Furbies" of our times, are threatening to swallow the entire electronic manufacturing capacity and eventually the Planet.
November 26, 2025 at 3:39 PM
Back in 1998 talking toys like the Furby could run on a Sunplus SPC81A microcontroller, a cut-down 6502 without the Y-register.
Modern talking toys, like the "Large Language Furbies" of our times, are threatening to swallow the entire electronic manufacturing capacity and eventually the Planet.
Modern talking toys, like the "Large Language Furbies" of our times, are threatening to swallow the entire electronic manufacturing capacity and eventually the Planet.
Make sure to turn on your DED ("Dark Emitting Diode") when prompting your "A.I.", to hide your traces.
November 26, 2025 at 12:00 PM
Make sure to turn on your DED ("Dark Emitting Diode") when prompting your "A.I.", to hide your traces.
Whatever you ask your "A.I.", always keep in mind that the Mighty Space Blanket is watching you.
November 26, 2025 at 12:38 AM
Whatever you ask your "A.I.", always keep in mind that the Mighty Space Blanket is watching you.
For #ChuckPeddleDay, I added an option to load the Oric Atmos ROM (1.1B that is) to the Virtual 6502 online emulator.
masswerk.at/6502/
masswerk.at/6502/
November 25, 2025 at 6:55 PM
For #ChuckPeddleDay, I added an option to load the Oric Atmos ROM (1.1B that is) to the Virtual 6502 online emulator.
masswerk.at/6502/
masswerk.at/6502/
"Sprachuhr" (Talking Clock) is a fun little Commodore PET program displaying an analog and digital clock (in BASIC) and announcing the time at full minutes (in ML).
Originally program by Heinz-E. Obermann for the 8000 series (1981), port for 40-col PETs by me (2025).
masswerk.at/pet/prgs/#sp...
Originally program by Heinz-E. Obermann for the 8000 series (1981), port for 40-col PETs by me (2025).
masswerk.at/pet/prgs/#sp...
November 20, 2025 at 6:38 PM
"Sprachuhr" (Talking Clock) is a fun little Commodore PET program displaying an analog and digital clock (in BASIC) and announcing the time at full minutes (in ML).
Originally program by Heinz-E. Obermann for the 8000 series (1981), port for 40-col PETs by me (2025).
masswerk.at/pet/prgs/#sp...
Originally program by Heinz-E. Obermann for the 8000 series (1981), port for 40-col PETs by me (2025).
masswerk.at/pet/prgs/#sp...
"PET Invaders" just got a liitle bit better.
(It's really just about when we stop any background sounds when a level ends. But polish is polish.)
Get Rev.2025-11-19 here:
masswerk.at/pet/prgs#pet-invaders
(It's really just about when we stop any background sounds when a level ends. But polish is polish.)
Get Rev.2025-11-19 here:
masswerk.at/pet/prgs#pet-invaders
November 20, 2025 at 6:55 AM
"PET Invaders" just got a liitle bit better.
(It's really just about when we stop any background sounds when a level ends. But polish is polish.)
Get Rev.2025-11-19 here:
masswerk.at/pet/prgs#pet-invaders
(It's really just about when we stop any background sounds when a level ends. But polish is polish.)
Get Rev.2025-11-19 here:
masswerk.at/pet/prgs#pet-invaders
Now, for our game, we just have to figure out, what keyboard is used, for which we peek into the ROM, in order to know which combinations we'll have to check for each of the keys in use.
And this is what our kbd scanning routine looks like:
And this is what our kbd scanning routine looks like:
November 19, 2025 at 4:55 PM
Now, for our game, we just have to figure out, what keyboard is used, for which we peek into the ROM, in order to know which combinations we'll have to check for each of the keys in use.
And this is what our kbd scanning routine looks like:
And this is what our kbd scanning routine looks like:
Regarding A. Brzenska, the oldest references is a German blog article from 2007: blog.c128.net/archives/17
Then, there's a compilation "Space Invaders MR NOP.d64", which shows a copyright message in just one of those games, the 2001 version, which is obviously hacked – and crashes.
Then, there's a compilation "Space Invaders MR NOP.d64", which shows a copyright message in just one of those games, the 2001 version, which is obviously hacked – and crashes.
November 13, 2025 at 1:14 AM
Regarding A. Brzenska, the oldest references is a German blog article from 2007: blog.c128.net/archives/17
Then, there's a compilation "Space Invaders MR NOP.d64", which shows a copyright message in just one of those games, the 2001 version, which is obviously hacked – and crashes.
Then, there's a compilation "Space Invaders MR NOP.d64", which shows a copyright message in just one of those games, the 2001 version, which is obviously hacked – and crashes.
Are there any links between A. Brzenska and Commodore Japan?
The other, lesser known Space Invaders for the PET, sometimes also known as "Galaxy Invaders", looks like this (featuring plain PETSCII blocks for game characters and a liberal amount of enemy missiles):
The other, lesser known Space Invaders for the PET, sometimes also known as "Galaxy Invaders", looks like this (featuring plain PETSCII blocks for game characters and a liberal amount of enemy missiles):
November 12, 2025 at 9:40 PM
Are there any links between A. Brzenska and Commodore Japan?
The other, lesser known Space Invaders for the PET, sometimes also known as "Galaxy Invaders", looks like this (featuring plain PETSCII blocks for game characters and a liberal amount of enemy missiles):
The other, lesser known Space Invaders for the PET, sometimes also known as "Galaxy Invaders", looks like this (featuring plain PETSCII blocks for game characters and a liberal amount of enemy missiles):
Moreover, there was a Space Invaders game by Commodore Japan. (Compare a short review in Compute! Magazine, Issue 2, Jan/Feb 1980.) Is it this one, or the other one with the smoothly moving PETSCII blocks? (I personally presume the latter.)
Dow we know more about this? Are there vintage ads?
Dow we know more about this? Are there vintage ads?
November 12, 2025 at 9:40 PM
Moreover, there was a Space Invaders game by Commodore Japan. (Compare a short review in Compute! Magazine, Issue 2, Jan/Feb 1980.) Is it this one, or the other one with the smoothly moving PETSCII blocks? (I personally presume the latter.)
Dow we know more about this? Are there vintage ads?
Dow we know more about this? Are there vintage ads?
Apparently, the famous Space Invaders for the Commodore PET (the one starting with the "how to produce sound effects" screen), was written by A. Brzenska for the PET 2001 in 1979 and then adapted for the 30xx and 40xx in 1980.
Does anyone know a historic source for this?
And what is "A." for?
Does anyone know a historic source for this?
And what is "A." for?
November 12, 2025 at 9:40 PM
Apparently, the famous Space Invaders for the Commodore PET (the one starting with the "how to produce sound effects" screen), was written by A. Brzenska for the PET 2001 in 1979 and then adapted for the 30xx and 40xx in 1980.
Does anyone know a historic source for this?
And what is "A." for?
Does anyone know a historic source for this?
And what is "A." for?