Exactly how NOT to make a multicart for the C64
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Re: Exactly how NOT to make a multicart for the C64
Why you heroes of lost hardware dreams, don’t do something c o n s t r u c t i v e for this community?
http://sleepingelephant.com/ipw-web/bul ... 87#p108190
See first of my comment on that topic.
Since no one can prove the opposite, I declare this as the first and cheaper but more efficient way to play 8-bit mono or 4-bit stereo samples on Vicy. Challenge is open
http://sleepingelephant.com/ipw-web/bul ... 87#p108190
See first of my comment on that topic.
Since no one can prove the opposite, I declare this as the first and cheaper but more efficient way to play 8-bit mono or 4-bit stereo samples on Vicy. Challenge is open
Valid rule today as earlier: 1 Byte = 8 Bits
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Re: Exactly how NOT to make a multicart for the C64
That reminds me of a Plenty Of Fish date I had once.MCes wrote: ↑Wed Jul 01, 2020 2:33 pmSomeone has already tried it, here is the video of the experiment .... https://youtu.be/M2o2FRwn_hg?t=232Gyro Gearloose wrote: ↑Tue Jun 30, 2020 11:17 pm Is there a way to simultaneously use an Eslapion product and a MCes product in a VIC-20?
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Re: Exactly how NOT to make a multicart for the C64
It's trivially easy to hook up a DAC to the VIC's user port. As a matter of fact, when I was in college studying electronics, many years ago, I brought my VIC with me. Instead of using the school's IBM-based computers I used my trusty VIC-20. Hooking up the user port to the Motorola MC1408 8 bit DAC was a fascinating experiment.Noizer wrote: ↑Wed Jul 01, 2020 3:35 pm Why you heroes of lost hardware dreams, don’t do something c o n s t r u c t i v e for this community?
http://sleepingelephant.com/ipw-web/bul ... 87#p108190
See first of my comment on that topic.
Since no one can prove the opposite, I declare this as the first and cheaper but more efficient way to play 8-bit mono or 4-bit stereo samples on Vicy. Challenge is open
https://datasheetspdf.com/pdf-file/1243 ... a/MC1408/1
I remember using the MC1408 circuit to create a low frequency arbitrary signal generator. Using a few lines of BASIC I created a 256 byte table of values and I made the VIC cycle through it and output the values through the MC1408.
I also used this DAC to adjust the output voltage of a LM317 regulator. A few lines of BASIC to ask for the voltage and calculate the 8 bit value and I had a programmable power supply.
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Re: Exactly how NOT to make a multicart for the C64
Hey, buddy, I studied a couple of years at university, I created a couple of things for the VIC-20 and for the C64 and then here comes this guy who declares everything I learned is bullshit, everything I say is bullshit and everything I sell is crap.
Good luck indeed trying to do anything constructive under the circumstances.
You're not going to like me. I did that project back in 1984 and it has nothing to do with samples of any kind. It uses the shift register of the 6522 to play perfect square waves of various frequencies.http://sleepingelephant.com/ipw-web/bul ... 87#p108190
See first of my comment on that topic.
Since no one can prove the opposite, I declare this as the first and cheaper but more efficient way to play 8-bit mono or 4-bit stereo samples on Vicy. Challenge is open
If that thing is able to play samples, I have no clue how.
Be normal.
Re: Exactly how NOT to make a multicart for the C64
All that studying left out DAC and PWM?If that thing is able to play samples, I have no clue how.
I'm just a Software Guy who has no Idea how the Hardware works. Don't listen to me.
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Re: Exactly how NOT to make a multicart for the C64
I think Eslapion should do the DAC and MCes does the PWM. I want my Mum and Dad to work together. I don't like it when they fight.
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Re: Exactly how NOT to make a multicart for the C64
I know perfectly well of DAC and PWM - I used both to make a uC controlled variable speed fan for aeronautics.
There's just none of either in the 2 pages of the VIC-20 P.R.G. mentioned in that specific thread.
I also used DAC and PWM to make a pure sine wave 12Vdc to 120Vac converter.
Be normal.
Re: Exactly how NOT to make a multicart for the C64
Yet you cant imagine how to play samples with a shift register? I see.
I'm just a Software Guy who has no Idea how the Hardware works. Don't listen to me.
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Re: Exactly how NOT to make a multicart for the C64
You could use it as a 1bit DAC, I suppose.
But that's completely besides the point. The basic program proposed in the PRG has one function only, play square waves of various frequencies and it does it magnificently. Where that thread turned to samples and DAC, it was no longer about what the OP tried to discuss.
Be normal.
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Re: Exactly how NOT to make a multicart for the C64
Hi all
Please keep the debate friendly and constructive, do you even know how tiresome this is to follow?
In behalf of our community “please behave boys”.
Please keep the debate friendly and constructive, do you even know how tiresome this is to follow?
In behalf of our community “please behave boys”.
Kind regards, Peter.
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Re: Exactly how NOT to make a multicart for the C64
No, because I haven't been following. I just switch off from topics that don't interest me and this one has been going around for years; gold plated connectors = good, non-gold plated connectors = bad. Got it.joshuadenmark wrote: ↑Fri Jul 03, 2020 1:36 am Please keep the debate friendly and constructive, do you even know how tiresome this is to follow?
eslapion is an old hand at making Commodore hardware accessories so I'll defer to his judgement on this one. My BB is still working fine after many years and he has nothing to prove here as far as I'm concerned. Case closed.
Re: Exactly how NOT to make a multicart for the C64
Thanks for the more considerate moderation compared to the 20Q programming thread I was contributing to that was expunged in a digital version of Fahrenheit 451 with no warningjoshuadenmark wrote: ↑Fri Jul 03, 2020 1:36 am Hi all
Please keep the debate friendly and constructive, do you even know how tiresome this is to follow?
In behalf of our community “please behave boys”.
Last edited by Vic20-Ian on Sat Jul 04, 2020 7:41 am, edited 1 time in total.
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Re: Exactly how NOT to make a multicart for the C64
Yeah my Dad's pretty cool!English Invader wrote: ↑Fri Jul 03, 2020 3:11 am eslapion is an old hand at making Commodore hardware accessories so I'll defer to his judgement on this one. My BB is still working fine after many years and he has nothing to prove here as far as I'm concerned. Case closed.
Accidentally created in a Martian military experiment.
Re: Exactly how NOT to make a multicart for the C64
That thread is titled "User Port Sound" so the discussion fits in that frameeslapion wrote: ↑Thu Jul 02, 2020 6:38 pm But that's completely besides the point. The basic program proposed in the PRG has one function only, play square waves of various frequencies and it does it magnificently. Where that thread turned to samples and DAC, it was no longer about what the OP tried to discuss.
Very interesting, but have you ever tried doing these things in machine language rather than basic?Gyro Gearloose wrote: ↑Wed Jul 01, 2020 5:36 pm ...
I remember using the MC1408 circuit to create a low frequency arbitrary signal generator. Using a few lines of BASIC I created a 256 byte table of values and I made the VIC cycle through it and output the values through the MC1408.
I also used this DAC to adjust the output voltage of a LM317 regulator. A few lines of BASIC to ask for the voltage and calculate the 8 bit value and I had a programmable power supply.
Valid rule today as earlier: 1 Byte = 8 Bits
-._/classes instead of masses\_.-
-._/classes instead of masses\_.-
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Re: Exactly how NOT to make a multicart for the C64
It was 25 years ago but I definitely remember that the loop for the function generator was in ML, otherwise it would have been glacial.
For sure the code that created the table of values is much easier in BASIC.
I enjoyed making the stupidest formulas possible, like (SIN / TAN ^ 2 * COS / pi)
etc
Just to see what is the craziest waveform I could show on the oscilloscope. The novelty wore off quickly however. It was too slow.
Reading 256 values from RAM and sending them out, I guess, would be what, 4 cycles for a LDA, 4 cycles for a STA, so 1MHz/8 = 125000 I/Os per second, and 256 values for a full cycle would give about 490Hz as the maximum frequency, but I guess you could improve that by unrolling the loop and using immediate mode LDA # and save two cycles that way, but I don't think I did that. It's also hard to get rid of the blip when the CPU has to jump back to the beginning instead of sending out a byte. Not clean.
490Hz fits with my recollection. Of course you can increase the frequency by reducing the time resolution of the table, maybe fit 2 to 4 cycles in there.
The voltage regulator would not benefit in the slightest from ML, just calculating a value and POKEing it to get the voltage doesn't need speed. At all.
My teachers didn't know what to make of me with my hand-painted zebra-striped VIC-20, but the coursework never specified I had to use the school's computers... My stuff worked and I passed the courses.