Commander X16

17 hours ago, BruceMcF said:

Which is why I argue it's probably OK if the X8 and the X16p DIY are released side by side, because they are hard to confuse with each other.

I very much agree with you, Bruce. But we both followed this project and this thread from the beginning and with paying attention to details. I noticed that members, who just read some announcements occasionally, are confused.

After all discussion in this thread I still think it's a good idea to release X8 alongside with X16 or even before X16. David made valid points in the first post of this thread. There is hardly a confusion here. Those who understand - will understand. Those who don't - will encounter things to confuse with and to complain to.

Re X8, X16, and VERA.  The X8 is more like Commodore's memory-mapped I/O.

Because college was soooo long ago, I had forgotten about using ports.  But because I first learned programming on Commodore machines, I thought memory mapped I/O was not only natural, but just right.

The X16's interface to VERA is a pair of ports, isn't it?  I can handle it, but I prefer memory mapped.

 

I just joined this forum to comment on this crossroad.

I am excited about the Phase 1 DIY board and even more excited about the community surrounding this effort.

My perspective on this project is that it is pragmatically realizing an 8-bit computer that many of us first learned on while incorporating new features that a beginner could still wrap their head around to understand and peek and poke at the whole thing.

Some of those new features are expandability and modularity including the VERA video card/sound card/storage and expansion bus.  These features make the system more relevant going forward in a world where kids look at 8-bit graphics and ask why is it blurred?

The heart of the system is an 8-bit processor and the limitations and idiosyncracies required.

This standard system is a challenge to builders and developers to do their best and when possible show their work on github etc.

I even see this as an important cultural thing where people have been shut out of building/fixing/tinkering with new tech at a hardware level because it is unapproachable.  This system will be approachable for centuries.  Education and curiosity will both benefit.

So based on the above I am ready to put some cash down on ten Phase 1 X16 DIY kits.  I will hire a couple guys in the Philippines to solder together 8 of them and resell those completed with a reasonable markup to cover labor.

I see having a finished Phase 1 board in your own personalized case and accessories as a badge of honor and pride.

I am also currently developing a Populous style game in Assembly for the emulator in order to learn more.

I want the audience for the software developed for the system to be as large as possible so I would support a much cheaper FPGA hardware emulation as long as it didn't segment the market with different specifications.  I also agree with a cheaper surface mount system with expansion if demand supports it which makes for a great Kickstarter test.

I would not support segmentation with a lower common denominator X8 / X16 bifurcation issue.  Why not use an X16 emulator in the meantime?  Perhaps there is a way to make the X8 and X16 even more similar?  The video ram window is a nice feature and I wish both could support it.

I also think the VERA video card/sound card/storage cartridge for other systems would be an excellent feature to increase the audience for porting new X16 software to these other systems.

I can imagine where the video card/sound card/storage for the X16 could be upgraded as a replacement daughter board or expansion card.

Thanks for reading this and reflecting on my perspective.

This whole project has made me very excited including this conversation.

13 hours ago, Ender said:

@BruceMcF Are you saying then that the range of CPU RAM directly maps to the VRAM from a hardware perspective?  That makes sense, I didn't know that.  The way I imagined it was just how I interpreted David's wording in the original post, but I don't know a lot about the hardware side, so your way probably makes more sense.  (Technically though, you could use it as CPU RAM if you really wanted to ?).

Yes. From the FPGA people have worked from pictures of Vera, there is a 128KB RAM module built into that FPGA. It is single ported ram, so only one FPGA circuit can write it or read it at a time. The fact that it is built in is how Vera can have an internal VGA dot clock of 50MHz.

The X16 uses all of that as "VRAM". The X8 reallocates 64KB for the 65C02 " soft core" to use.

From unofficial information about the X8, the page in the X8 CPU system address at $0400 is always the page of VRAM set by the VRAM bank register. The page at $0500 always maps to a fixed set of Vera registers. The I/O that takes part of page $0700 always accesses the control and data registers for that I/O. The VRAM window "moves around" in VRAM, but its location in the CPU memory map is fixed.

5 hours ago, Colin said:

I have read through most of the thread, so I don't think this has been asked or discussed, maybe I missed it.  Why can't the case be included with the kit?  I would purchase a kit version of the X16, but it would be more attractive to me if the case could be included.  Is it that anticipated sales of a kit version would be way below the minimum 1000 units that the case manufacturer requires?

It's almost certainly economies of scale. When you subtract the kits bought by people who don't want cases, the number of large cases can easily be less than 1000. Indeed, if you don't have cases, but have "support" tiers that include keyboards and some different goodies (name on a supporters page, printed docs, etc), it's a lot easier to put together a crowdfund campaign that can be structured to break even on keyboards than to structure one that can break even on cases. You might even want to set the "go" volume on kits at 200 and cap the first campaign under 500 X16p kits, to make sure you avoid "fulfillment hell" and the bad reputation it brings.

If the crowdfund is a runaway success, then there should be financial flexibility to just produce more kits and sell them on pre order in batches. And if it funds but doesn't max out, you know where to set expectations on the market.

If there is also an X8 with keyboard tier in addition to keyboard support tiers and a range of 200-500 kits in the first campaign, hitting break even on keyboards would be pretty straightforward, while hitting break even with the Micro-ATX cases could easily be infeasible.

48 minutes ago, BruceMcF said:

Yes. From the FPGA people have worked from pictures of Vera, there is a 128KB RAM module built into that FPGA. It is single ported ram, so only one FPGA circuit can write it or read it at a time. The fact that it is built in is how Vera can have an internal VGA dot clock of 50MHz.



The X16 uses all of that as "VRAM". The X8 reallocates 64KB for the 65C02 " soft core" to use.



From unofficial information about the X8, the page in the X8 CPU system address at $0400 is always the page of VRAM set by the VRAM bank register. The page at $0500 always maps to a fixed set of Vera registers. The I/O that takes part of page $0700 always accesses the control and data registers for that I/O. The VRAM window "moves around" in VRAM, but its location in the CPU memory map is fixed.

Do you have any links to the source of those addresses/pages on the X8? 

Is the memory at page $0600 affected?     What 'part' of page $0700 is also spoken for?  

 

2 hours ago, Snickers11001001 said:

Do you have any links to the source of those addresses/pages on the X8? 



Is the memory at page $0600 affected?     What 'part' of page $0700 is also spoken for?  



 

See the general chat thread at:


That also explains more clearly what I mean by "from unofficial sources". This is tentative until/unless there is a specification from official sources, but it makes sense based on the simplest way to give access to the part of the internal FPGA RAM dedicated to the Vera functions.

 

 

Thanks to the x16 team for giving the community this option.

The reality is your bringing out a system 40 years after the cpu inside it was cutting edge, and this will be a system that will have possibly a few thousand owners, why dilute that pool by having different levels of system ability, that is X8 vs X16 this makes no sense to me.

I understand you wish for a low entry point to fit the original intent to allow cheap entry point due to the rising costs of a c64 or apple 2e etc, but isn't that what emulation attempts to replace anyway?

On another note, just wanted to take this opportunity to thank David and the team for not giving up on this project i've been looking forward to it since falling over over it earlier this year.

Great idea and really look forward to building one.

 

2 hours ago, MarkV said:

The reality is your bringing out a system 40 years after the cpu inside it was cutting edge, and this will be a system that will have possibly a few thousand owners, why dilute that pool by having different levels of system ability, that is X8 vs X16 this makes no sense to me.

I think the harsh reality of economics are at play. Supply issues and cost increases related to chip fab constraints aren't going away anytime soon, which along with the logistics, practical and cost overheads of buying/storing/shipping the intial X16p mean the likely price of the kit is rocketing, which will weaken sales overall (and the device needs some economies of scale to break even).

My guess is that without the safe, low risk income from sales of the X8 the X16 might never become a reality - (certainly not the surface mounted or embedded versions need to reach a price point and critical mass of sales). There is a very, very niche market for a totally DIY solder it yourself product costing $500+ (once the bundled custom keyboard, cost of a case and PSU, shipping and taxes etc are taken into account). Even less for one if you need to spend another $150+ to have it hand assembled for you. 



Releasing the X8 would incur almost zero financial risk (its already developed, works, and the parts aren't nearly as constrained as the X16 BOM, it can be produced locally etc), could likely be sold for comfortably sub $100 (including a load of margin to pump in to the big boy X16 development and de-risk the jump to a surface mounted version), would demonstrate that the X16 line-up isn't vaporware (in terms of a physical product seeing release), and would get a near identical (if constrained) version of the VERA platform out there in v1.0 form to encourage developer and tutorial writer efforts.



And that's before considering that the X8 (with its constraints) might be a device a lot of people might actually want.

8 hours ago, BruceMcF said:

See the general chat thread at:




That also explains more clearly what I mean by "from unofficial sources". This is tentative until/unless there is a specification from official sources, but it makes sense based on the simplest way to give access to the part of the internal FPGA RAM dedicated to the Vera functions.



 



 

Sheesh.   So on the X8, we would lose the ability to put ML code BASIC helpers/wedges at $0400 to $04FF, $0500 to $05ff, and part of page at $700. 

Additionally, since there's no longer banked ram, the 8K at $A000 to $BFFF that on the X16 is 'page 0' of the banked ram and reserved 'for KERNAL/CBDOS variables and buffers" is the only RAM in that range.  

So, uh, if you want to include a machine code routine as a BASIC helper (such as sound effects like the simplest sound library, or a little routine to handle collision detection, or your own interrupt handler for music, or a wedge to implement some currently unavailable bitmap stuff from BASIC (e.g., circle, flood fill)),  etc., where do we put it?    Sounds like it has to go in the 39K of actual BASIC memory now. 

Anyone know the 'pokes' for the X16/X8 in terms of the pointer to move down the top of BASIC memory like addresses $37 and $38 on the C64?!