This is just a concept for now but for more info see my 6502 page in my signiature for more info as it is updated.

My concept is based on a multi-board expandable architecture. The slot will be similar to a PC expansion slot (i.e. PCI, AGP, ISA, PC/104, etc.). It will consist of 9 boards:

CPU - 6502 with a 32k ROM for in-Chip use
ROM - 1M includes BASIC interpreter as well as a Question/Awnswer new song writer that sends the code out to...
Cartridge - Flash EEPROM (Almost any)
Sound - quarter-inch out
TV - RCA / S-Video / Co-Ax
AT / PS/2 - Keyboard
Power - 110 V AC / 5 V DC
Base - 8 32 pin slots
RAM - 1 M

Here is a diagram:

A = PWR
B = CPU
C = ROM
D = RAM
E = KBD
F = SND
G = TVO
H = CAR



(Concept)
On Boot it shows an ASCII Logo and asks if you want to make a new song or not. If no then it loads a song from CAR. If yes then it asks you questions about the new music (Octave, tempo, etc.). It then throws that into the BASIC "play" function. Then you can save it on a blank CAR.
(/Concept)

If you have any thoughts or ideas or concepts or if you could help in any way just let me know. I am doing this for my 8th-Grade science project.

zeckalpha@gmail.com

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6502/Music - www.6502.tk

Your project sounds interesting. Have you put any of your sub-system designs down on paper yet? It all sounds pretty straight forward. Have you considered that the 6502 can only address 64k directly? I'd be interested in your sound system as well.

Let us have more details as you define them.

Good luck!

Daryl

Thank you.



No. I just have general ideas on how it will work.



Is that positive or negative?



I did not know that but I was going use a second 6502 sort-of like an interfacer. It will function similarly to a northbridge on a modern PC motherboard. It will mange only data storage. So an architecture design is:





It is sent out to a microcontroller and it turns an Oscillator on and off (More detail later).



This is fine. Thanks for the 64k mem access thing... But I got a workaround.

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6502/Music - www.6502.tk

On your memory expansion, how 'bout eliminating the second 6502 as a middleman and using a window of, say, 8K in the main memory map to access the much larger memory. Bits 0-12 of the processor's address bus will serve as the same bits 0-12 of the extended memory bus, but the extended memory's higher address bits will be latched into some output device on the 6502's bus. When you set the higher bits to select what 8K portion of the large memory you want to be working with, that 8K portion will be windowed into the 6502's own 64K memory map, just as if it were in main RAM.

It’s positive in that you are trying to create a system with subsystems that have already been successfully implemented, therefore making your goals reachable.

Daryl

Like this?
Say you want to paint a picture that is 65k... You look through a hole to view only a small amount at a time... then you paint what you see... then you move the wood to move the hole and you repeat?



Thanks for the responses

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6502/Music - www.6502.tk

Close, but not quite. Unfortunately I'm not equipped to post diagrams, so I'll just make it as clear as I can in text.

8K=8192 bytes. 2^13 is 8192, which is how many locations you can access with 13 bits.

Let's say you put your 8K window at addresses $6000-7FFF of the 6502's memory map. Then, let's say you have an 8-bit latch at 6502 address $8800 in your I/O space. That lets you have 13+8 address bits for your extended memory, allowing 2^21 addresses, which gives two megabytes. (You could add another 8-bit latch if you want more memory. 8 more address bits would allow half a gigabyte capacity.)

We'll call each 8K section of the extended memory a "bank". To select what bank you're working with at the moment, you write the bank number to your latch at address $8800. Now all 8192 bytes of that bank are directly accessible to the processor in its own memory map at addresses $6000-7FFF. To use your analogy, that section of the extended memory gets moved right behind your 8K hole, lining up perfectly so when you look through it, it's like there's not even a hole-- it just appears to be part of the same surface. You don't move the hole, but rather the larger surface behind it. You select what "tile" of that larger surface is going to line up with the hole.

So the low 13 address bits of the extended memory are the 6502's own 13 low address bits, while the higher address bits come from the latch(es) you write to. The extended memory's 8 data bits, the phase-2 signal for its chip selects, and the R/W\, are connected directly to the 6502's buses.

This is probably most useful for data, but you can have sections of program in the extended memory too. You just have to be careful about certain things; for example, writing to the bank-select latch is something that generally should not be done by a program running directly from extended memory. Edit, May 2014 (almost 10 years later!): My code in PIC16 microcontrollers has been overflowing the first 2048-word program page into the second, and the mickeymousities of the program-memory page-select bits have caused an awful lot of bugs, and wasted a lot of my time. Doing this kind of thing on a 65xx system, for data only, with only part of the memory map being a window into a much larger memory space, might work fine; but I sure wouldn't want to duplicate the PIC's problems. What a rotten design!

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Thanks for this... It is harder to set up than my idea but I think it will be save time in the long run.

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6502/Music - www.6502.tk