Happy New Year and happy hacking in 2025!

[BigDumbDinosaur]

drogon wrote:

A 65C02 is a luxury I don't have.

What’s stopping you from getting one?

Quote:

I could save a few 10s of bytes with the C02 instructions (Mostly STZ and PHX/Y ...) and right now 10 bytes would be great!

Not only would you be saving some bytes, you’d be saving some clock cycles, although STZ executes at the same pace as STA—STZ’s value is in its convenience.  Especially in interrupt handlers, I’m always looking for ways to trim clock cycles. 

Some new-to-the-65C02 instructions, mainly TRB and TSB, are handy for managing bit fields and can replace the sequence of operations that would be required with the NMOS MPU to accomplish the same thing.  The firmware in my POC units is peppered with those two instructions, as well as BIT #.

[drogon]

BigDumbDinosaur wrote:

drogon wrote:

A 65C02 is a luxury I don't have.

What’s stopping you from getting one?

I only have a 28 pin CPU socket.

Which is the point - This is Project 28. A minimal 6507 system with just 4K ROM, 4K RAM and runs Basic.

(The RAM chip is under the 28-pin EEPROM)

-Gordon

[barnacle]

drogon wrote:

Keen to see your Basic though - keep going!

Cheers Gordon,

In spite of only occasional updates on the thread recently, it's progressing. The 'getting numbered lines into memory in the right order' is a pain, though solved in the C version; it needs a lot of helper bits (memmove, findline, list, comparison etc) all to work correctly before it all works and as you might have seen, comparisons have been a bit of a marathon...

It's currently holding at about 2k, assembled.

Neil

[drogon]

barnacle wrote:

drogon wrote:

Keen to see your Basic though - keep going!

Cheers Gordon,

In spite of only occasional updates on the thread recently, it's progressing. The 'getting numbered lines into memory in the right order' is a pain, though solved in the C version; it needs a lot of helper bits (memmove, findline, list, comparison etc) all to work correctly before it all works and as you might have seen, comparisons have been a bit of a marathon...

It's currently holding at about 2k, assembled.

Neil

Impressive. Keep going! I have DO...WHILE in mine an am pondering sacrificing it for wiring-style GPIO commands on the VIA...

-Gordon

[BigDumbDinosaur]

drogon wrote:

I only have a 28 pin CPU socket.

Ah-so!  I didn’t make the connection.

[DRG]

I know it's nearly February, but better late than never.

In life, 2025 will be... interesting for me. In April, I'll turn $3B. At the time of writing, I have one more week of working life left, then I retire. I just felt the time was right. My mother passed away last year at 80 years of age. I'd by lying if I said that didn't have some bearing on my decision - it made me contemplate my own mortality more than I'd ever done. No point working away the remaining days if I can be doing something else.

In term of 6502 aspirations, it's just to keep progressing my knowledge. I'd ultimately be ecstatic if I could design & build a 65C02 creation with video output and the icing on that cake would be the ability to run BBC basic on it. I don't think I'll ever get there, however. I know I'll have a lot more time on my hands but that can't necessarily overcome the amount of knowledge & experience I DON'T HAVE.

For some reason, I have this "hankering" to interface a Raspberry Pi Pico to the 65C02. Oh, I know it's been done before, but learning how it's done and writing C code of that complexity are lofty goals for me. It's a good job it's all about the journey, not the destination!

Dave

[plasmo]

It is interesting that many 6502 projects are working toward video/keyboard solutions. It is fun to see so many diverse solutions presented here. I also have a 6502 video/keyboard project under the topic of "6502 as VGA controller" and a closely related project with 3.3V 6502. Unfortunately I'm off detour with Z80/68K projects, even have a PowerPC project on the back burner.

My 6502 VGA/PS2 to-do list said: get rid of one chip by using ATF1504, add 1-bit audio, port EhBASIC, run BadApple with sound. Maybe I'll get around to it by year end 2025!
Bill

[barnacle]

My reasons for going that way were simple:

(a) I didn't have _anything_ around the house that could display PAL (or NTSC), and frankly I didn't feel that a relatively simple 6502 system had the horsepower to drive even VGA resolution beyond simple monochrome text, hence using a pi to sort out the VGA pictures; and

(b) parallel keyboards are close to, or actually, extinct; USB is less than universal, particularly when applied to 8-bit systems; hence we are effectively left with PS/2 keyboards (which, again, are not trivial in memory requirements for keyboard mapping unless you can transfer the logic off board). Building a physical keyboard which can be mapped to a memory scan is again a non-trivial activity (and not cheap!)

As I have explained ad nauseam, I don't have any great interest in configurable logic chips; I'd rather use glue logic - even though that is restrictive in both board size and circuit speed. But I'm happy to use external software to handle things...

Knocking up a basic 65(c)02 system is a piece of cake; half a dozen chips. Making it useful is a bit harder - definitely improved if it has a keyboard and some sort of video output, rather than using a terminal. But what any of us develops depends on our interests...

Neil

[greghol]

I'm surprised that you haven't done any test boards for all the Dragon Ball CPUs you have yet.

Greg

plasmo wrote:

It is interesting that many 6502 projects are working toward video/keyboard solutions. It is fun to see so many diverse solutions presented here. I also have a 6502 video/keyboard project under the topic of "6502 as VGA controller" and a closely related project with 3.3V 6502. Unfortunately I'm off detour with Z80/68K projects, even have a PowerPC project on the back burner.

My 6502 VGA/PS2 to-do list said: get rid of one chip by using ATF1504, add 1-bit audio, port EhBASIC, run BadApple with sound. Maybe I'll get around to it by year end 2025!
Bill

[plasmo]

I do have large number of Dragonball in BGA package and some in QFP. I have test boards for both, but I really want to build a dragonball mezzanine board for EPM240 dev system, something like the 68SEC000 mezzanine board but use dragonball instead.
Bill