The J64C

[J64C]

At present the specs are as follows -

CPU: W65C02 or W65C816 @ 18.625Mhz
RAM/ROM: $0000 - $3FFF (16384 bytes)
Screen RAM: $4000 - $44E2 (1250 bytes)
Character ROM: 4096 bytes (transparent to system at present)
I/O: Nothing yet, but have 9 GPIO pins to play with and and exposed address/data bus.

This is just starting out and will change as I add and modify things, but is pretty flexible. The only real main constraint is RAM, but this was somewhat of a test project with the next one already in mind. But, plenty to play with here.

[BigDumbDinosaur]

J64C wrote:

The letters look mangled at this speed, but they are fine. I haven't added any form of vSync testing yet, so they are getting overridden mid raster.

So I see.  Some of the As seem to have top hats. 

[barnacle]

Very polite of them. They're going to Ascot.

Neil

[BigDumbDinosaur]

barnacle wrote:

Very polite of them.  They're going to Ascot.

...or the Kentucky Derby. 

Seeya At the Races!

Whoa, Nellie!!!

[J64C]

Aww you guys, horsing around again!

Hopefully get to have more of a play around with this over the weekend. Would be great to get BASIC running in it, which I don’t have much experience in doing yet. I have had BASIC running in the past by using C64 ROM’s. But with the more limited space I have to work with on this one I may not be able to use that same sort of hack. But you never know.

So, if you guys have any tips on that front, I’m all ears. I’m not too concerned what variety of BASIC at this stage. Just something I can inject keystrokes in to would be awesome.

[gfoot]

Gordon's GIBL is really easy to get running, I would recommend it at least as a starting point. It is quite minimal but gives you a decent amount of functionality from the get go. If you end up needing something more complex you can cross that bridge later.

BBC BASIC is also meant to be not too hard to get running, maybe so long as you can load it at $8000 or $B800 - it interfaces to the operating system through just a few system call entry points and you can just provide dummy handlers for those if you don't care about the features that require them. It is famously large though (16K)

[BigEd]

There is a slightly subsetted BBC Basic too, by JGH, which leaves just enough room for a mini-OS in the same 16k ROM.
See this thread
https://stardot.org.uk/forums/viewtopic.php?t=31735

[BigDumbDinosaur]

J64C wrote:

Aww you guys, horsing around again!

Snicker!

Quote:

Would be great to get BASIC running in it...So, if you guys have any tips on that front, I’m all ears.

How about EhBASIC?  It’s not as powerful as BBC BASIC, but is also not as corpulent.  One thing to consider with any of these BASICs is they tend to need a lot of zero page storage to run.  Dunno if that would be a concern in your system.

[J64C]

That’s an option too. Not too worried about the pro’s and con’s so much at this stage. Would be nice to have something meaningful running.

Zero page is also not a problem. The entire memory map is up for grabs and useable. Maxing out at 32K on this system though.

[J64C]

Wrote the start of a somewhat loose emulator, so I can now I can work on some sort of kernel rather than the five minute cycle of loading it in to my hardware to test.

[BigDumbDinosaur]

J64C wrote:

Wrote the start of a somewhat loose emulator, so I can now I can work on some sort of kernel rather than the five minute cycle of loading it in to my hardware to test.

Looks as though the As lost their top hats and decided to go informal. 

What brand of o’scope is that sitting in between the monitors?

[J64C]

BigDumbDinosaur wrote:

J64C wrote:

Wrote the start of a somewhat loose emulator, so I can now I can work on some sort of kernel rather than the five minute cycle of loading it in to my hardware to test.

Looks as though the As lost their top hats and decided to go informal. 
What brand of o’scope is that sitting in between the monitors?

Indeed they have!

The oscilloscope is a cheap and nasty 4 channel from Vevor, which in turn is a rebadged Owon SDS1104. I also have an Owon SDS1102 (two channel). For my purposes they have both been fantastic.

Funnily enough I managed to get the Vevor for sub $300 (AUD) and to get the identical Owon version of it, you are looking at at least double that.

[J64C]

gfoot wrote:

Gordon's GIBL is really easy to get running, I would recommend it at least as a starting point. It is quite minimal but gives you a decent amount of functionality from the get go. If you end up needing something more complex you can cross that bridge later.

BBC BASIC is also meant to be not too hard to get running, maybe so long as you can load it at $8000 or $B800 - it interfaces to the operating system through just a few system call entry points and you can just provide dummy handlers for those if you don't care about the features that require them. It is famously large though (16K)

Funnily enough, I made a start on getting Tiny Basic running on this system and realised just now that Gordon’s GIBL is based upon that. Might be worth going straight to GIBL, now that I realise this.

[okwatts]

Hi
It's been a while and as far as I know little has changed since 2023 but you might want to check out this link: https://github.com/chelsea6502/BeebEate ... /README.md
It has no graphics and save/load but I did get this to run on Rich Cini's version of Daryl Rictor's SBC2.71, burned to a ROM using the ACIA for IO.
Would love to see this for CP/M-65 (running on a Nano) but the relocatable binaries might be a real issue.

[drogon]

J64C wrote:

gfoot wrote:

Gordon's GIBL is really easy to get running, I would recommend it at least as a starting point. It is quite minimal but gives you a decent amount of functionality from the get go. If you end up needing something more complex you can cross that bridge later.

BBC BASIC is also meant to be not too hard to get running, maybe so long as you can load it at $8000 or $B800 - it interfaces to the operating system through just a few system call entry points and you can just provide dummy handlers for those if you don't care about the features that require them. It is famously large though (16K)

Funnily enough, I made a start on getting Tiny Basic running on this system and realised just now that Gordon’s GIBL is based upon that. Might be worth going straight to GIBL, now that I realise this.

There are many TinyBasics.. Mine (GIBL; Gordons Interactive Basic Language) took the IL (Intermediate Language - a sort of VM designed to write TinyBasic interpreters in) from something called NIBL (National Industrial Basic Language - runs on the INS8060 or sc/mp CPU), hence the name...

One downside of GIBL is that it's more or less only for the ca65 assembler from the cc65 suite. IT may work for others but there are many macros that will need looking at.

I think the current 'release' is version 3 - I'm up to 6 now on my Project-28 board.

Also; Porting. At the end of the day you just need character in and character out. Once you have that you're all set to go.

And that's the same for MS Basics too - e.g. the 65C02 variant of EhBasic or any of the ones from the popular pagetable site - I built the one that ran on the Commodore PET, etc. from that site and got it going in a few minutes - same again, just supply character in and out. (Actually, I think it might also benefit from a "character ready" function. But that's it. https://projects.drogon.net/microsoft-basic/

BBC Basic - One of those you either love or ignore. I love it but I also love the simplicity of TinyBasic. It rarely gets much mention here, sadly. Probably a tribal thing. I started by writing enough hooks into my exiting monitor to support the bare essentials for BBC Basic and when it worked I wrote my own Acorn compatible operating system from scratch to better support it - including file handling and all that. If you want a Basic with built-in assembler then that's the one to use.

There are other Basics - Paul Robson has some 6502 and 65816 Basics on his github - aimed at the Foenix, neo6502 and X16 platforms. Ought to be portable as far as I can see but I've never tried.

And of-course there is VTL-2..

-Gordon