My father made a 6116-based battery backed rom emulator that had nothing but the rom plug on a ribbon cable in terms of connectivity. You could program it with any eprom programmer. It behaved like a “button-press-erasable” eprom. Since he already had eprom programming figured out, an ersatz-eprom that could be electrically erased seemed like the most straightforward way to go. Slightly more cumbersome perhaps than serial downloads, but when you had an eprom programmer card in the CP/M machine, it was quick enough.
I will forever have the number 76 burned into my brain? Why 76? The TIA and CPU run in sync with the raster beam. No interrupts. 3.58MHz colorburst frequency, divided by 15kHz horizontal television frequency = 228 rounded to integer. the 1.19MHz system clock is colorburst divided by 3. So 3 machine cycles for each complete color clock. 228 / 3 = 76, 76 machine cycles from one side of the horizontal line, to the other. WSYNC register to cause the READY line on the 6507 to be asserted by the TIA, to wait for the next horizontal line. This gave sanity. You had to use the RIOT timers to keep track of how many lines you had off screen to do computation (both vblank and overscan) 20 byte playfield register (symmetrical/reflected playfield register), 2 8 bit player registers, 3 1 bit missile and ball registers. Any writes to those registers caused an instant change in output, and thus needed to happen before they needed to. Player/missile/ball registers were designed to be easily checked via carry overflow (and games like Combat would abuse the stack pointer to do this very quickly). All of which had to be carefully scheduled on screen before they were to be visible (you had the horizontal blank on the left to facilitate stuff on the very left of the screen), all of which had to be done each and every frame, so up to 60% of your available CPU time was spent hammering the TIA to draw the screen. You became acutely aware of precisely how long each instruction took (in cycles) to ensure that you never went over 76 (or you'd spill over to the next line. There's a reason many early games had two line kernels, what we called the display portion of the code) All player, missile, and ball positioning done via a reset register, which due to system clock, could at best case be positioned in 15 pixel increments, to counteract this, horizontal move registers were provided to scoot a player/missile to the right place, when the HMOVE register was accessed. This caused a black bar "comb" on the left of the screen. Collision happened through a series of registers, playfield to player to ball to missile etc, all of which would latch, and could then be read (e.g. during overscan), then subsequently cleared via CXCLR. 128 bytes of RAM. 4K of addressable ROM space. No read/write line, so any additional RAM bifurcated the address space. RIOT provided the RAM, and the I/O (controllers), as well as the only timers in the system. Since no interrupt, you had to poll INTIM to determine if a timer was done. INTIM would continue to count after expiry, and this was often exploited. So yeah, 76. always in my brain. -Thomas Cherryhomes :)
We want to present all perspectives and will continue to in the future. Please also check out our talks from Stacy Devino and Jennell Jaquays too, as they had very interesting presentations at VCF Southwest 2023.
Boy does this bring back memories! I didn't develop games but did work on embedded systems. Got to use an Applied Microsystems 6809 Emulator (in circuit emulator). That was a fantastic tool for debugging.
She's only three years older then I am, but those were insanely powerful years she lived through. She's definitely insane, gifted, talented, and brighter then I ever was, but insane. I may not agree with her choices, but I would gladly die defending her right to make those choices. Period. A Brilliant person, thank you for these amazing nuggets of your personal history and your bravery.
Then those who would see your way of life destroyed shall destroy it all the while you die defending them do it.. and in your final moments you will see the only thing you defended was your own ending. Good day.
Amazing video , thanks a lot for sharing ! This is what you call top notch hacking in a good meaning of this word. I so appreciate Rebecca’s work and sense of humor ! I guess with this level of a brain power you don’t need to carry phone chargers around since your brain can charge them wirelessly :)
I absolutely love this woman! Lol !
Such an awesome history lesson and what a character !! 😊
Damn Good Stuff !!!
My father made a 6116-based battery backed rom emulator that had nothing but the rom plug on a ribbon cable in terms of connectivity. You could program it with any eprom programmer. It behaved like a “button-press-erasable” eprom. Since he already had eprom programming figured out, an ersatz-eprom that could be electrically erased seemed like the most straightforward way to go. Slightly more cumbersome perhaps than serial downloads, but when you had an eprom programmer card in the CP/M machine, it was quick enough.
Created on an Apple ][ GS. Apple ][ Forever! Had to see... It's there !
I will forever have the number 76 burned into my brain?
Why 76?
The TIA and CPU run in sync with the raster beam. No interrupts.
3.58MHz colorburst frequency, divided by 15kHz horizontal television frequency = 228 rounded to integer.
the 1.19MHz system clock is colorburst divided by 3.
So 3 machine cycles for each complete color clock.
228 / 3 = 76, 76 machine cycles from one side of the horizontal line, to the other.
WSYNC register to cause the READY line on the 6507 to be asserted by the TIA, to wait for the next horizontal line. This gave sanity.
You had to use the RIOT timers to keep track of how many lines you had off screen to do computation (both vblank and overscan)
20 byte playfield register (symmetrical/reflected playfield register), 2 8 bit player registers, 3 1 bit missile and ball registers. Any writes to those registers caused an instant change in output, and thus needed to happen before they needed to. Player/missile/ball registers were designed to be easily checked via carry overflow (and games like Combat would abuse the stack pointer to do this very quickly).
All of which had to be carefully scheduled on screen before they were to be visible (you had the horizontal blank on the left to facilitate stuff on the very left of the screen), all of which had to be done each and every frame, so up to 60% of your available CPU time was spent hammering the TIA to draw the screen. You became acutely aware of precisely how long each instruction took (in cycles) to ensure that you never went over 76 (or you'd spill over to the next line. There's a reason many early games had two line kernels, what we called the display portion of the code)
All player, missile, and ball positioning done via a reset register, which due to system clock, could at best case be positioned in 15 pixel increments, to counteract this, horizontal move registers were provided to scoot a player/missile to the right place, when the HMOVE register was accessed. This caused a black bar "comb" on the left of the screen.
Collision happened through a series of registers, playfield to player to ball to missile etc, all of which would latch, and could then be read (e.g. during overscan), then subsequently cleared via CXCLR.
128 bytes of RAM. 4K of addressable ROM space. No read/write line, so any additional RAM bifurcated the address space.
RIOT provided the RAM, and the I/O (controllers), as well as the only timers in the system. Since no interrupt, you had to poll INTIM to determine if a timer was done. INTIM would continue to count after expiry, and this was often exploited.
So yeah, 76. always in my brain.
-Thomas Cherryhomes :)
I was born in 76.
Nuff said 🤘
Rebecca is wonderful! It felt like reading a book where you just can't stop, remembering and imagining those vintage days! Thanks for sharing!
what an inspirational lady.
This was GOLD!!! 👏👏👏 This was seriously blowing my mind the whole time. A true pioneer sharing the goods! Thank you!
Awesome to hear this history.
This lady is a genius
A legend
Burger Becky is legend.
She’s a legend!
Watch a lot of these vcf talks, I don't remember ever seeing a woman talking, genuine lady and very well put together and interesting presentation.
We want to present all perspectives and will continue to in the future. Please also check out our talks from Stacy Devino and Jennell Jaquays too, as they had very interesting presentations at VCF Southwest 2023.
LOVED This!!! Such great stories and memories of tech-days gone by!
Boy does this bring back memories! I didn't develop games but did work on embedded systems. Got to use an Applied Microsystems 6809 Emulator (in circuit emulator). That was a fantastic tool for debugging.
She's only three years older then I am, but those were insanely powerful years she lived through.
She's definitely insane, gifted, talented, and brighter then I ever was, but insane.
I may not agree with her choices, but I would gladly die defending her right to make those choices.
Period.
A Brilliant person, thank you for these amazing nuggets of your personal history and your bravery.
Then those who would see your way of life destroyed shall destroy it all the while you die defending them do it.. and in your final moments you will see the only thing you defended was your own ending. Good day.
*older than (comparative)
*brighter than (also comparative)
*brilliant
*person. Thank (to fix your comma splice run-on)
I love this women to ,Incredible lady .
*woman (singular)
women = plural
It's like "man" vs "men," but with "wo" on the front.
*too. Incredible
*lady.
Genius is beautiful.
This was like being in a computer game museum with the world's greatest docent. I couldn't get enough.
Amazing video , thanks a lot for sharing ! This is what you call top notch hacking in a good meaning of this word. I so appreciate Rebecca’s work and sense of humor ! I guess with this level of a brain power you don’t need to carry phone chargers around since your brain can charge them wirelessly :)
I really need to get to one of these VCF events to see these kind of talks.
Apple I supported the 6800 CPU, not the 6809.
Atari used PDP-11 dev systems. So did Activision really use PDP-8s?
Thanks a lot! Hope these unreleased GS games might somehow be leaked if no other solution were found...
*was
BurgerOS :).
I love this stories
*this story. (singular)
plural: these stories.
Where is Nox Arcana for the IIgs?? maybe she should be working on that instead of toying around at these useless events.
It's a man, baby!
WTF is wrong w you