welcoming newcomers to the 6502 world

[eye3sg]

Hi, I'm Ondra. I'm glad I found this forum. Here are a few things about me.

I have been interested in electronics, electricity, and tinkering since I was a child. It started with taking apart toys and figuring out how they worked. I played with a soldering iron, switches, and light bulbs. The first computer I had was a Didaktik M, a Czechoslovak clone of the ZX Spectrum. I programmed in BASIC. It was just child's play, but I enjoyed it.

Later, I continued with x86 in DOS. I programmed simple scripts in the shell. Then I got to the PIC16F84 processor. I programmed in assembler. It was really hard, but also very rewarding. Only here I really understood how a computer works.

Embedded systems still interest me and I am interested in them. But I feel that they are getting more complex. Yes, MicroPython is an amazing language, but assembler and simple hardware have their charm. Knowing exactly what it does.

More and more it draws me back to the roots. Now I am interested in the 62C02 processor. I build a KIM-1 clone based on Arduino. I enjoy working with low-level programming. I like systems like the keyboard input monitor, because I can program right away. It reminds me a lot of old Paradox security systems.

[BigDumbDinosaur]

eye3sg wrote:

I build a KIM-1 clone based on Arduino.

Welcome to 6502 land.

How did you build your clone? Do you have any photos you can show us? (Photos can be attached to posts here, as well as PDFs and ordinary text files.)

[maurice6502]

Hi 6502 lovers,
I am an old hardware & software developer, just retired and now with a little time to try do develop some crazy ideas
Thank you for this space and for shared know how, 6502 was my first processor (I start with KIM1..) and I dont forget all adventures with this evergreen pioneer.
Hear you soon !
maurizio

[Dr Jefyll]

Welcome, maurizio! I too am fond of crazy ideas and I look forward to hearing more about your activities in the past and going forward.

-- Jeff

[GARTHWILSON]

Welcome.  Let's hear those "crazy ideas."  Crazy ideas are often DOA; but other times they're the kind that make me say, "That's ingenious!  So simple, and yet a perfect solution!  Why didn't I think of that?!"  Even now, closing in on 50 years after the introduction of the 6502, I expect there are still great techniques, especially in software, that remain to be thought of, or at least published.

[maurice6502]

GARTHWILSON wrote:

Welcome.  Let's hear those "crazy ideas."  Crazy ideas are often DOA; but other times they're the kind that make me say, "That's ingenious!  So simple, and yet a perfect solution!  Why didn't I think of that?!"  Even now, closing in on 50 years after the introduction of the 6502, I expect there are still great techniques, especially in software, that remain to be thought of, or at least published.

Hi Garth,

there are a huge quantity of 3D and very interesting articles in your website and in this forum, it's no easy for me to find specific argument.. but I will try in the next year
In the meantime pardon me if I ask infos about my first curiosity: sharing RAM with external device, to allow pseudo "transparent" use of one intelligent HMI.
In the past I solve this job with dual port RAM (see attachment) but hardware implementation is not cheap; I remember that old Commodore machines share part of system ram with video device (VIC 6561)
Well, in your opinion should be possible to manage system RAM during PHI2=0 when 65C02 dont access to RAM/ROM ?
For example, with one system board that run 65C02 at 1.8432 we will have:

- PHI2 active more or less for 270 nS and inactive for similar time
- PHI1 active for 270nS , alternate to PHI2
- we dont permit access bus for 50 nS from PHI rising to avoid overlap on systemn address/data bus

Teorically - with 70nS RAM - we have more than 100nS to read or write 1 byte of RAM (obviously non cuncurrent writing, unsemaphored and asinchronous data exchange require use of 2 separated memory block..)

I suppose that this opportunity was already discussed, do you have memory of that ?

Thank you in advance !

maurizio

[nrrd]

Hello all. I've been lurking for a while, reading all the great posts and building up my knowledge of all things 6502.
I've also been watching Ben Eater's videos, reading the 6502 primer, and thinking of building an 8 bit computer.

My software programming job is so complicated now (you'd probably call me a "full stack developer", but I work in a research institution) that I'm getting interested again in the computers of my youth.

I had a Dragon 32 (not great!) then a ZX Spectrum 128K (okay, but the colour clash was off putting) and then an Amiga. This was by far my favourite computer family ever. I had an A500+, with the RAM expansion, then an A1200 with hard drive, 68030 50MHz accelerator and 8MB RAM, and could program it in 68000 assembly language. I did actually work as a games programmer (PS2 era) for a few years before returning to academia and research.

I also enjoy electronics, having built synths and guitar pedals, I'd like to build something in complexity between the Spectrum and A500, and I think a 6502 system would fit the bill.
Something like an Apple IIc+, but with better graphics and sound. I'll probably use the new-ish Arduino Nano R4 as a VGA and sound card.

So, hello everyone! I've got a question to ask straight away, but I'll put that in another thread.

[Infinite-Mantra]

Howdy howdy, y'all! I'm new to 6502 Assembly, but I thought it'd be good to start off on the right foot! I got "6502 Assembly Language Programming" by L. Leventhal, and I figured this forum might help me fill in any other gaps in my understanding.
The reading is dense, you know? But I don't want that to stop me.

I'm excited to meet everyone; I can't wait to get started on my first project!

[barnacle]

Welcome!

You might consider Rodnay Zaks' "Programming the 6502", also. It currently appears to be listed (second hand) for a ridiculous amount of money, but the Internet Archive hosts a scan which might help you decide. https://archive.org/details/Programming_the_6502_OCR

It has a particularly good section explaining each instruction, the modes available, and the flags affected.

But remember that if you buy a new processor now, it will likely be a WDC65c02, which has extra instructions which can make some things easier!

Neil

[BigDumbDinosaur]

Also, there is the official WDC programming manual that covers the 6502, 65C02 and 65C816 in great detail.  I recommend you download it, and have someone print and bind it for you, as it is a very comprehensive reference.

[Dr Jefyll]

Infinite-Mantra wrote:

I'm excited to meet everyone; I can't wait to get started on my first project!

It's nice to meet you, Infinite-Mantra.

As for your first project, are you planning to use a wireless breadboard? I do see the appeal of those, but there are some serious drawbacks. Most notably, a low-quality breadboard won't grip the component leads adequately, leading to connections which may just barely work most of the time... but that's not enough! Just one microsecond of flakiness is all it takes to crash your program, which means you face the threat of maddening intermittent failures unless you use a good quality board -- such as one from Twin Industries, for example.

(Or, forget about breadboards and use wire wrap, point-to-point wiring or a PCB!)

-- Jeff