>The (old) datasheet specified that MLB was active (low) for the last 3 >cycles of a RMW instruction. I have found experimentally that this is not >the case, at least with the DEC zp opcode. MLB goes low on the dead >cycle after the first data (read) cycle, stays low for the next cycle (write >data ...

Wikipedia of course!

Hi Everyone,

The person could use an FRAM from

http://www.ramtron.com/

This device is a "dream machine" for the original posters application. This is because it can function as a pseudo RAM and NVRAM at the same time.

Note, I haven't actually used one of these in practice, so be sure to read the ...

Hi Everyone,

Remember... the ST7 from ST micro is a 6502 look alike. It IS a single chip device with Flash, RAM, and IO.

Note, I haven't actually used one of these yet.

Cheers,

Paul

Try this manual from the manufacturers web-sitel
(it is quite large :) )

http://www.westerndesigncenter.com/wdc/ ... manual.pdf

It has everything (and I do mean everything).

Cheers,

Paul

Hi,

I remember that 8250's have pretty slow access times.
Watch your bus timing parameters when connecting.

Bye,

Paul

Hi Everyone,

The bus structure is simple and it's a Von Neuman architecture. The 6089 is nice but you can't get it in CMOS any more (the 6309 is out of production).

Cheers,

Paul

Hi Everyone,

This is a heavily debated subject, but I'll try and to speak about the most basic definition (there isn't really an absolute one though) of a RISC processor. Some people define RISC processors as ones where the instruction length (of opcode and operand) is fixed where CISC processors ...

Hi Everyone,

What is comical is that in the Atari piece (see link in last post) the fifth paragraph has a mistake about the 6800! The 6800 sets the "sign" bit in the condition code register after a load of the accumulator. Consequently, you can follow a "LDAA $65" instruction with a BPL/BMI ...

Hi,

Pull-up resistors are just regular resistors.


Bye,

Paul

Hi Garth,

You've touched upon somthing big.

Starting from the late 70's as silicon got faster, micros that had "asynchronous" buses had an advantage over the synchronous bus processors like the 6502 and 6800 family.

Why, because you could run a Z80/8085 at higher and higher speeds and still ...

Hi Wally,

Thanks for the heads-up.

Bye,

Paul

Hi Everyone,

Am I the first to see that Western Design has put-up a programming manual for the 6502/65816?

http://www.westerndesigncenter.com/

Look at the bottom right hand corner of the main page.

Way cool.

Cheers,

Paul

Look in the documents archive of 6502.org

Cheers,

Paul