Commander X16

For amusement or bemusement, I'm comparing 8 Bit Guy's article (http://www.the8bitguy.com/2576/what-is-my-dream-computer/) with the Commander X16.  I expect this to of course be an almost perfect match.  Let's double check!

 

I'll rate each requirement on a "ten-points" scale.

9/10: OFF THE SHELF COMPONENTS

Quote

[...] I prefer to avoid any FPGA or microcontrollers if possible, but that’s not a deal-breaker.

-1 for the FPGA.  (To be fair, though, I suspect this is unavoidable.)

10/10: CPU

The 65C02 at 8mhz ticks all the boxes.

10/10: MEMORY

Quote

I would want 128K or 256 of static RAM, with possibly the ability to upgrade it.  If using 6502 then there will need to be some sort of banking [...]

...exactly what the X16 does.

10/10: VIDEO

Quote

...I’d definitely want the computer to be able to output Composite or VGA...   ...I’d want it to be similar to 8-bit machines of the era, possibly with different modes.  640×480 would be fine for a maximum resolution.... I could see this chip being an FPGA or microcontroller if need be.

Again, VERA ticks the boxes.

 

10/10: SOUND

VERA has the PSG (and PCM) so we're done.  Adding the YM chip is nice for synthesizer fans like 8BG, but frankly that's not the deal-breaker.

 

10/10: STORAGE

He wants an SD card; if necessary, the Commodore IEC serial connection would let him use SD2IEC.  So we get both.  Win-win.

 

10/10: OPERATING SYSTEM

He wants a Commodore "successor" machine, with the Commodore fullscreen editor, that uses PETSCII.

Quote

...Hopefully somebody would even write emulator support for it so that we could code and test on a PC.

...and he got that, too. 

 

 

OVERALL PHILOSOPHY

 

Quote

I want the machine to have some of the conveniences of the modern world, such as SD storage and modern keyboard and video standards.  But, at the same time.. I don’t want it to be “too powerful” because then you begin to lose the magic of an 8-bit system.  

Yup.

 

In short, the X16 is not missing any of the "requirements" of the "dream computer".

Call it 69 out of 70 points.

When I compare this with, for instance, Ben Eater's 6502 breadboard, or the FW8B PET single board, or the PE6502, I see this:

10/10 Off the Shelf

10/10 65C02

0/10 128K+ Memory.  These generally live within the 6502's 64K limits, and so don't deal with RAM banking.

10/10 Composite or VGA Video*: Composite for the PET and PE6502, "Poor Man's VGA" for Ben Eater's video card (might need some improvement tho...)

0/10 Sound.  I don't think any of these have sound (does the PET?)

Storage (SD): 2/10 for the PET (IEEE-488), 5/10 for the PE6502 (fast serial), and 0/10 for Ben's breadboard (no I/O).

Commodore Operating System: 10/10 for the PET.  0/10 for the PE6502.  2/10 for Ben's breadboard (because you probably could just drop in a KERNAL).

 

So out of 70 points, 

The standalone PET gets 42 points.

The PE6502 gets 35 points.

Ben's breadboard 6502 gets 32 points.

On the other hand, Ben's breadboard projects, being super flexible, have the most potential.  If you can drop in a KERNAL into Ben's project, then it would be in a tie with the standalone PET.  If you could drop in a sound synthesizer, then it would surpass the others.

If you rejiggered the system to use memory banking, you'd then be close to "dream computer" level (there's one schematic posted on Ben's website: https://www.reddit.com/r/beneater/comments/k6tgfg/a_simple_way_to_add_banked_memory_to_be6502/).

You'd need to attach an SD or IEC port.

Of course, all those bits would add up to quite an achievement.

 

44 minutes ago, rje said:

 

9/10: OFF THE SHELF COMPONENTS

-1 for the FPGA.  (To be fair, though, I suspect this is unavoidable.)

 

2/10: OFF THE SHELF COMPONENTS

Gray market YM2151/3012 do not meet the criteria.  I am quite certain others will disagree with this opinion.

23 minutes ago, picosecond said:

2/10: OFF THE SHELF COMPONENTS



Gray market YM2151/3012 do not meet the criteria.  I am quite certain others will disagree with this opinion.

They don't meet it perfectly, but then again, Vera FPGA and YM2151 grey market, 65C02 stock, VIAs stock, glue logic stock, RAM stock, FlashROM stock ...

... 2/10 is a silly score to give on that basis. That's at least a C, so set it at 7/10.

2 hours ago, BruceMcF said:

... 2/10 is a silly score to give on that basis.

The scale is wholly arbitrary so I don't see why any score should be labelled "silly".  I thought I was being generous.

Here's the thing:  I don't care at all about purity tests.  I care about building reliable computers.  Using these parts poses risks that nobody on the design team can quantify.  Maybe the supply will be great quality and they have no problems.  But if not, what then?

• 
  Pay someone to screen the parts?
  


• 
  Develop a test procedure (not so easy) and screen parts themselves?
  


• 
  Hope for the best and ship spares to kit builders who complain about no sound?
  


• 
  What about damaged but not dead parts that die some months after systems are shipped?
  

None of this matters for hobbyist builds.  All of it matters when shipping systems in quantity.  It's just not worth the risk to reputation and personal bank accounts to take chances with iffy semiconductors.  Maybe 2/10 was too generous.

9 minutes ago, picosecond said:

The scale is wholly arbitrary so I don't see why any score should be labelled "silly".  I thought I was being generous.



Here's the thing:  I don't care at all about purity tests.  I care about building reliable computers.  Using these parts poses risks that nobody on the design team can quantify.  Maybe the supply will be great quality and they have no problems.  But if not, what then?

• 
  Pay someone to screen the parts?
  


• 
  Develop a test procedure (not so easy) and screen parts themselves?
  


• 
  Hope for the best and ship spares to kit builders who complain about no sound?
  


• 
  What about damaged but not dead parts that die some months after systems are shipped?
  

None of this matters for hobbyist builds.  All of it matters when shipping systems in quantity.  It's just not worth the risk to reputation and personal bank accounts to take chances with iffy semiconductors.  Maybe 2/10 was too generous.

Yaaaaaaawn we already know that if the YM2151 supply craps out then they'll roll an FPGA daughterboard. Literally posted by Lorin less than 48 hours ago.

2/10 is patently vindictive. 7/10 is reasonable. If you're that convinced that the FPGA YM2151 will become mandatory, maybe a 6/10.

38 minutes ago, StephenHorn said:

If you're that convinced that the FPGA YM2151 will become mandatory, maybe a 6/10

Supply crapping out and poor quality parts are different things.

FPGA YM2151 gets 10/10 from me.  Then it would be 100% new, off-the-shelf parts.  I don't care if parts are fixed-function vs programmable.  I do care if they are new vs used.  If a suitable new fixed-function part isn't available FPGA is a great solution.

BTW, despite not posting here often I do read every one of Lorin's posts.  Don't assume I am uninformed because my perspective is different from yours.

 

7 hours ago, rje said:

When I compare this with, for instance, Ben Eater's 6502 breadboard, or the FW8B PET single board, or the PE6502, I see this:



10/10 Off the Shelf

FW8B PET and PE6502 both use microcontrollers for video. I think David would prefer this less than FPGA.

9 hours ago, picosecond said:

The scale is wholly arbitrary so I don't see why any score should be labelled "silly".  I thought I was being generous.



Here's the thing:  I don't care at all about purity tests.  I care about building reliable computers.  Using these parts poses risks that nobody on the design team can quantify.  Maybe the supply will be great quality and they have no problems.  But if not, what then?

It IS an ordinal scale. 2/10 is saying that is there is only one step between this board and not meeting the criteria in any way whatsoever, and seven steps between this board and meeting the criteria perfectly.

I don't have any experience buying from these channels, but since the source will be Chinese, they are indeed likely to prescreen the chips to sort between those they sell to their ongoing customers and those they sell to hucksters selling to people gambling on components on eBay. If someone with experience buying from the first channel reports that they have good experience, I don't have any reason to assume that that will change for these orders.