6502.org

Welcome! Thanks for the detail and the links about this machine.
Cheers
Ed

Welcome to our little 6502 world.

Welcome, Anonimo. Sounds like quite a project.

Hello all,

I've been batting around joining for about a month, and I have a question that doesn't seem adequately answered in the forum for me to join. But that's in another thread I'll make later today.

I'm a 23 year old with a bachelor's in ECE who is finishing up his masters in said field. For the past 3.5 years, I've been interested in the old IBM PC world, and take less interest in machines that I have no hope of fully understanding or have limited control over, such as the Raspberry Pi (though I have one anyway ). I have an IBM PC, XT, AT, Compaq Portable, and a few others. Not very interested in the Commodore or Apple world, though I have a VIC20 from my dad.

In about May 2013, I decided to broaden my horizons and try programming a non-IBM PC system- the good ol' SNES/Super Famicom. While I can't say I'm wonderful at creating beautiful art, I learned enough to at least to make an event queue for Vblank, and print strings to the screen. I don't intend to stop SNES programming, but I do take breaks until time/energy permits.

I find the '816 an interesting chip, in design, features, and assembly language- and I like how the programmers manual is very in depth. However, it seems it's features tend to be underutilized (ABORT signal, VDA/VDP for cache), considering the SNES core adds a lot of supporting hardware, and it was used in relatively basic home computers. I would be interested in using it's various control signals and features in a new design as an educational exercise just to see how it could be done.

Recently, I got my amateur radio license, and have been batting around making a hardware solution for at least the digital transfer modes- a small embedded computer. I feel I could possibly put the '816 to good use in a small design for basic digital transfer modes attached to the input to an amplifier. I've done some (flawed) sketches, but so far everything I've thought of for this design is described here.

This is a long term project, and won't be something that I can even meaningfully construct for a few months from now. However, I still have questions leading up to the time that I build it, and I hope the members here can bring me up to speed. This forum seems pretty relaxed and accommodating to new users- and I hear you can use new younger members .

Great intro, and welcome! I like to think we're relaxed and accommodating, so it's nice to hear that we come across that way.
Cheers
Ed

Welcome to our 6502/65C02/65C816/??? world.
They appear to be underutilized, although there may be embedded applications we don't know about that do use the more arcane inputs and signals. I make use of VDA and VPA in my POC unit. ABORT is tricky—timing is exact and unforgiving. Also, ABORT doesn't actually abort instructions, it just discards the computational results. Some of the other signals, e.g., E, MX and MLB, have very limited value in the majority of applications.
I read your post:
Implementing 65C816-compatible DMA is something that I've chewed on ever since I got SCSI working on my POC unit—having DMA would produce a substantial performance boost. I've considered implementation by using the 65C02 as a co-processor and by making a CPLD act as a DMAC. I've abandoned the cp-processor idea, as I don't think it will produce enough of a performance gain to justify the required hardware hoop-jumping.

Although I note your aversion to using programmable logic, it really is the logical(!) path to achieving maximum performance. However, starting out using discrete logic is the best way to learn how to build a stable-running unit.
There is no shortage of compatible devices that are current production. The 65C816 and its support devices (65C21, 65C22, etc.) are readily available from major electronics sources. Ditto for 74-series logic, although older logic families are disappearing. I used 74AC logic in my POC unit, in PDIP.
Hey, watch it! Just because I'm old, feeble, on life support and...uh...a big, dumb dinosaur doesn't mean you young whippersnappers can just barge right on in here and take over. Actually, I and other other members tend to be somewhat amazed about how much attention the 6502 family continues to get from new generations of computer hobbyists. So welcome and please start a topic about your ham radio project.

Hi all,

I'm another younger member (I'm 22 and just graduated with a BS in computer science). I've been planning on building a 6502 based computer for the past year or so and I've finally got it assembled and I've started programming it in the past couple weeks. Many thanks to this site and particularly to Garth Wilson's 6502 primer. I don't have a background in electronics so all these resources have been invaluable.

Right now I have a wdc 65c02 running on a breadboard at 1.8432MHz with 32kb sram, 8kb eeprom, a 65c22, a 65c51 and a couple nand gates for address decoding. I'm in the process of adding a serial lcd module controlled by the VIA and I just recently got serial running and a monitor program to load programs into ram.

My future goals for this project are to get forth running (although the last time I sat down to learn forth I got distracted and got into haskell instead...) and I'd like to get this machine off the breadboard and make a wire wrap SBC as well, but I might consider using the 65c816 the second time around. I love the simplicity of the 65xx hardware and the fact it was designed so long before I was even born makes it that much cooler.

So thanks everyone, I'm glad there's such an active, friendly and intelligent community for the 6502!

Just graduated with a BS in computer science, and interested in Forth? I didn't think that was possible. Forth is too outré for most computer science departments. On the bright side, judging from the Forth conversations I've seen on this forum, I'd say you've come to the right place.

Welcome and congratulations for diving right in and building a working unit. If you decide to build with a 65C816 for your second project be sure to look at my POC website and Daryl Rictor's SBC site (links on the 6502.org projects page). The '816 is a bit of a different breed of cat than the 65C02 and offers quite a bit more power and flexibility, but remains well within the reach of a hobbyist.

Indeed, welcome!

Hi,

I'm a sysadmin who has dabbled in electronics and programming a bit in the past, always trying to learn more and challenge myself.
I've done a bit of C and python in the past for work and for fun, now it's time to get right down to Assembly

I love learning how things work, and playing with the 6502 is teaching me a lot of fun and interesting things!

So far I've got a 6502, 8k rom and 64k of ram on a breadboard driving one of those 16x2 LCDs, but I'm going to order some peripheral chips so I can handle serial and other inputs, can't wait!

The information on this site has been invaluable, and so has the help I've received from the forum members, so thanks!

Good to hear your story, and here's a belated welcome from me! (I think I see some breadboarding in my future...)

Welcome. You've definitely come to the right place to learn about the 6502 family.

Hi

Programmer with a habit of messing with electronics... I recently build a slow backplane based 6502 mini computer.

Then I decided that what I really wanted was a 65c816 based single board computer. I'm currently in the process of designing that - so I figured I might as well join this forum.

/norby

Welcome. Just type 65C816 into the search functions and plenty of posts will pop up. Also, have a look at Daryl Rictor's website and my POC site for some design and construction ideas.