Very sorry to hear you are not enjoying it any more. Don't be surprised if you are drawn back in! Your work is amazing, and greatly appreciated by all here.

On the SD card issue, I was thinking about something similar a couple of years ago and was considering smart cards. They are basically just EEPROMs in a card, pretty easy to read with minimal code, but I don't know what the largest size available is.

Thanks, it has been fun.
I will repost my last message so it is on a fresh page here, in case someone comes here and reads from the bottom up...


This may sound a bit crazy, but I am going to retire from my electronics hobby.

Lately I have not been enjoying it much. Vulcan was fun, but that's about it.
In a world of Arduinos, Raspberry Pi, and non-hackable technologies, it's just not the same.
The days of jacking into a modern keyboard or display are gone. You need FPGA for anything.
Code is bloated, pre-made hi level cores and libraries. Not my kind of thing.
All of the reasons that made me start Vulcan-74 (see first post) are now overwhelming.

No big deal really, I have a LOT of other interests!
I change my life like this when I feel things getting stale. It was a long time coming!

Anyhow, I hope this thread will inspire others, it has been a slice.
I won't be returning, and all of my boards, parts, and tools are boxed and put away.

For the next decade, I intend to pursue self sustainable living (old technology mixed with new).
Also working on several other new web ventures that have zero to to with hacking or electronics.

This forum was a great source of community for me, and I enjoyed y stay here.
I would ask that this thread be locked now. I would like to end on this note.

6502.org.... Please keep the Old Spirit alive!!!!

Cheers!
Radical Brad

I once made a SPI-only driver for SD cards, and have never met a card that didn't work. There are a bunch of differences, though, and the spec requires very careful reading and jumping through the right hoops to make it work. If you ever decide you want to try this again, let me know.

Very cool you stopped by 6502.org and shared your project with us!
I enjoyed following your work on here (I was lurking) and lucidscience.com.

Good luck in your future endeavours!

Live long and prosper.

_________________
65Org16:https://github.com/ElEctric-EyE/verilog-6502

Ok, I have come back to sanity!
Seems I had cabin fever thanks to a long Northern winter, and needed to expand my interests somewhat.

Since my last post, I have been mixing electronics with heavy metal, and enjoying the hobby again.
My summer project is a huge autonomous Robot called The Sentinel...

http://forum.atomiczombie.com/showthread.php/10080-The-Sentinel-Autonomous-Farm-Robot-Build-Log?p=102527#post102527

It's been a while since I sparked up my welder, but being outdoors has really helped.
So, I will not be quitting electronics as a hobby, and will not abandon Vulcan-74.

I will however, be "re-purposing" Vulcan-74 into an even more radical project!
Until I have the details worked out, I will keep it a secret, but let's just say it will probably have 4x the number of ICs when it's complete.
... and yes, it will have a single 6502 at it's core!
This time interfacing new technologies will not be necessary, so the frustration factor will not be there.

It will be some time before I am down in this lab again, but will post details on the "Vulcan-74 Reloaded" when I get the chance.
Ok, back to the chicken coop and 800 pound robot for now!

Cheers!
Radical Brad

Dang it ... where's the "thumbs up" button?!?!

Mike B.

Back to sanity?? Erm, uh... Ok, Brad!

Looking forward to hearing about The Sentinel, though. All the best,

Jeff

_________________
In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html

So, I know this is a dormant thread, but I just came back to check on it, and I have to get this idea out of my head...


So many tradeoffs talking about boot schemes!

I think I have a solution that adds some parts to gain incredible versatility: Two cartridge ports AND a smallish PROM.

Big port: Lots of pins, parallel bus. If there's a cartridge in here, the internal PROM is disabled, the 6502 boots from the cartridge, and you do whatever -- could even put additional hardware in the cartridge and it'll have access to whatever signals you bring it. BUT, if there's no cartridge in this port, the internal ROM should be enabled instead.

Small port: SPI flash or SD card, just leave the big port empty and the internal boot ROM should have a program to make the 6502 speak enough SPI to find the flash or SD device, read bits from it, possibly grok a filesystem or two. Either bulk-load the whole RAM, or just load the first morsel and jump to it, allowing a chainloading scheme as previously described. (Using the "magic key at the start of the sector" trick would allow a filesystem-agnostic hunt for the secondary bootloader sector, which could then contain filesystem-specific routines for loading this particular card, allowing even future filesystems to be supported by the same old PROM.)


Pretty sure that's a CT4810, aka the first PCI SoundBlaster.

Hello, and congrats for identifying the SoundBlaster PCB!
Vulcan-74 is far from dead, but this thread will be sleeping for some time as my summer chores keep me from it.

I no longer need SPI or SD for this project, as it is going through a radical and extreme change.
Vulcan-74 will no longer be a Game System when it is reborn.
Most likely, I will rip out everything that has been done so far to start over!

I am keeping the new design a secret until I have time to detail my plan, but here are some small bits...

- Totally redone VGA section with higher resolution. Will now be 512x480 instead of 400x300.
- Possibly 4x the number of IC originally planned. Will probably need 4 of these massive breadboard panels.
- Absolutely no interfacing required with external modern devices. Everything to be "self contained".
- Circuitry will include both 7400 logic as well as "era correct" analog circuitry.
- Everything will be controlled by one or more onboard 6502's. Parallel EEProms to boot this time.

For those that want to venture a guess as to what I may create from ~500 retro ICs....
I am currently making a few Vactrols from CDS Cells, LEDs, and black tubing!

The new Vulcan-74 is going to be a hell of a thing!

Cheers,
Radical Brad

Today I finished my Homesteading chores ahead of schedule and had some time to cool off in my basement lab.
I have been hacking around on design ideas for the new Vulcan-74 project, and made some progress.
before I commit to the huge breadboards, I like to test ideas on my smaller 16"x12" breadboard.

Today's successful test was entitled... "How to NOT require a Vactrol".

For those that don't know what the purpose of a Vactrol is, here is a quick description...
It is a voltage controlled resistor that can swing from almost 0 ohms to infinity.
One purpose of a Vactrol is to alter the level of an analog signal with a control voltage.

A Vactrol is a difficult to find part, so I just made one that worked perfectly fine.
One diffused red LED and an LDR wrapped together in black tape... done!

In my case, I needed the Vactrol to become part of a digitally controlled potentiometer.
I fed an 8 bit value to an R2R DAC and then to an op-amp to control the LED brighness.
The Vactrol then passed an audio signal with a volume level proportional to the 8 bit value.
This worked perfectly, but during my yard work today I thought of a way to go all digital instead.

Since a 6502 does not offer hardware PWM, I decided to make a bolt on solution using a few logic ICs.
A 74HC590 timer is clocked at 20MHz, allowed to continuously wrap around from 0 to 255.
The 8 bit output of the counter is fed to Compare Value A of a 74HC682 magnitude comparator.
A 74HC574 is set by the 6502 with the Compare Value B going to the 74HC682 comparator.
When the count value A is greater than the test value B, the result pin is LOW.
As you can guess, this creates a fast 20MHz PWM signal with 8 bits of resolution.
Now the 6502 has fast 8 bit PWM with the help of 3 common logic chips.

I then feed the PWM value to the Enable pin of a 74HC4066 analog switch, which toggles the audio signal.
The result is a perfectly proportional 8 bit digital potentiometer that is more predictable than a Vactrol.
I can now control the volume level of the audio signal with a range from 0 (silent) to 255 (loudest).

This digital PWM potentiometer is going to come in handy in the new design. I may require 16 of them!
The reborn Vulcan-74 will also have a large Analog Section that will require digital interfacing.

So this is all positive, and I am now laying out some of the new design.
While I test ideas on the smaller board, I am tweaking the VGA Generator for higher resolution.
I am ripping up everything but the bare VGA Generator, as I won't really need the Sprites anymore.
I do however, require as much resolution as possible to display detailed information.
512x480 should be decent, and will offer a text screen of 64 x 60 characters.

Ironically, my massive double breadboard is not even close to large enough now!
I currently have 48 breadboards together, for a total working area of 740 square inches and 42,336 tie points!!
Rough calculations are showing that I would need 4 more of these large boards to complete everything!
Luckily, I am duplicating a lot of the deign 8 identical times, so I will be able to test at least 2 segments.
Hand wiring the final board with what will probably be 500-700 ICs is going to be a bit of work, no doubt.

Since the new Vulcan-74 is no longer a Game System, I will soon start a new thread with the details.
Besides the 6502(s), the only other parts to be used will be basic 7400 logic chips and some op-amps.
There will be NO modern components, and no requirement to interface (for input) with modern hardware.
All input devices will be mostly home built or hacked, so no more pesky SD cards or computer keyboards.
Vulcan-74 is going to be a self contained system that I intend to enjoy for many years.

Ok, so what type of monstrosity will require 600 retro logic ICs and a 6502?....

An 8 Voice Digitally Controlled Synthesizer with a built in Tracker and VGA Display, of course!

I have a massive list of features that I am putting together for the new thread.
Will try to get down here and post on the next rainy day!

Cheers,
Radical Brad

You still have yet to implement a 6502 hard/soft core in your design.

I don't fault you, because your apparent skill in designing with discrete TTL is impressive.

I'm sure I'm not the only one continuing to watch your progress Brad, as your older projects are very impressive and you do not disappoint...

I just wish you would join club FPGA.

_________________
65Org16:https://github.com/ElEctric-EyE/verilog-6502

Thanks!

I do actually have a membership to Club FPGA, but I hang it on the door on my way in here!

In 2009, I did an FPGA / Verilog Game System with similar specs to where Vulcan-74 was at.
This one did NTSC 320x200, and could also interface to any external host. I called it Lazarus-64...



Also did a few HDMI and other VGA designs, sporting resolutions up to 1024x768 with 24 bit color.
I must admit though, that the HDL designs are not as fun for me. The OldSkool is what does it for me.
When it comes to just wanting to "get-r-done", then I usually go either AVR or FPGA.
On the massive Farm Robot I am making, I have several FPGAs and a PIC32 going into the navigation system.
The FPGA will do some real-time machine vision, and the PIC32 will handle motor control and sensors.

Ok, back to the good ole days... I must forget all things FPGA and remember that 8 bits is enough bits!
My next experiment will be a Resonant Low Pass Filter with 8 bit digital control.

Cheers,
Radical Brad

Just a few ramblings as I experiment with ideas and hardware...

Wow, it's amazing how clean 8 bit samples sound when played back at 44 KHz in Stereo.
Of course, that speed is nothing for the SRAM and counters, so now I can use the 512k DIP Memory.

I now have the basics hardware working to play one Stereo Voice of the 8 I intend to have.
Each Voice has its own 1024K (512K per channel), and 16 bit accuracy for the Frequency Control.
Samples are sent from SRAM to an R2R DAC, and then through the PWM (8 Bit) Volume Mixer.
So in total, the Sound Generator section of Vulcan-74 will have 16 x 512K=8MB SRAM (AS6C4008).

Now since I am not allowing external input, one might wonder; how are "Samples" are going to get into the SRAM?
Well, this is where the 6502 earns its keep... all Waveforms are going to be generated programmatically.

A very intuitive and feature rich Waveform Editor will be presented as part of the "Operating System", which will be powered by one or more 6502s. The Vulcan Operating System (VOS) will be responsible for several tasks, which include Tracker live recording and playback, Waveform editing, Song and pattern editing, Digital control of analog functions, and many other tasks, such as writing information to the 512x480 VGA display and scanning the piano keyboard matrix.

I envision the Waveform Generator as a graphical presentation that allows the musician to draw complex envelopes that control the many analog features such as low pass, resonance, tone shaping, echo, etc. The actual base waveforms will also be generated by complex formulas mixed with user input. So to make say a distorted drum hit, the user would start by choosing white noise as a base waveform, and then add a steep attack and decay, followed by a slow decay and release. A similar envelope could be chosen for the distortion effect and then layered with a bit of tone shaping, cross channel reverb, and maybe a bit of random equalization. This complex Waveform will be shown visually on the VGA display, and can be played "Live" by pressing keys on the Piano Keyboard to see how it sounds at various frequencies. When the Waveform sounds good, the user then selects "Write to Voice" and the 6502 will send the sample data to the appropriate set of SRAMs for that Stereo Voice.

I have also decided that for the most part, Vulcan-74 is an instrument to be played live, although it will also be a fully featured "Tracker". I used to mess around with OctaMED way back in the day, but found it tedious when compared to simply jamming out on my Ensoniq (thanks Bob!). So Vulcan is going to bridge both Worlds for me, with the ability to record tracks directly on a piano keyboard, and will even capture the many analog knobs I intend to add for effects. All analog controls will first pass though an ADC0804 ADC chip and then to the 6502, which will record the digital values. Vulcan will also allow playback of all other Voices while recording, so you can keep on layering tracks to make a song. As for tracks and Patterns, VOS will allow editing much like any Tracker such as OctaMED, Renoise, etc.

The fact that all analog controls are internally converted to digital for capture by the 6502 will allow for a much more expressive recording. Trying to "Edit" such things in a tracker leads to a robotic sound, in my opinion. Quantization is nice when you have no sense of timing, but when you are trying to capture something like a lazy lag or live jam, it just ain't gonna happen by plugging stuff into an editor!

There will also be a set of "Final Effects" that apply to the entire output. These will also be presented to the user as sliders and knobs, but converted digitally inside Vulcan-74. Final Effects will have their own "Tracks" as well, which can be captured during playback. An example of this would be the user tweaking the Resonant Low Pass Filter knob as the song winds into the Lead Synth Track (think... Second Reality Demo music).

For musical input, I plan to hack a keyboard and jack right into the matrix. That way I am not stuck messing around with MIDI.
For the user interface, I may do something similar with a computer keyboard, and simply gut the thing so I am keeping to my "no modern interfacing" rule.

Anyhow, there will be an amazing number of features and the chip count is going to be insane!
Everything is going to be done in 7400 logic... Audio and Video Generation. The 6502 will just be the "Conductor".
Besides jacking into a sound card to record the final Music, there will be no connection to the modern world.
Vulcan-74 will be a true Retro Music Station made of parts available in 1980 and still available today.

Cheers,
Radical Brad

Sounds similar to a 16-bit sound sampling keyboard I used to own back in the late 1980's called the Ensoniq ASR-10. 16-bit audio was all the rage, and CD players were just making their entrance into the market with their 44.1Khz 16-bit oversampling. I wasn't a musician by any means, but the RE-sampling one could do with the mixing and feedback available from 32 voices, in order to create new sounds, was incredible.

_________________
65Org16:https://github.com/ElEctric-EyE/verilog-6502

With all of those cool goodies and retro components, portability might be an issue ... you're going to have to gut a full-size upright piano to fit it all in!

Mike B.