Galaxy & Zen80 boards

[Duke]

Just thought I'd create a new thread for posting progress on my (maybe) coming boards, rather than cluttering the M4 thread even more.

A short video of the current progress of Galaxy board (booting SymbOS).

https://youtu.be/NAWO1etR-vQ
Now RAM expansion is working (allocated 320KB for the CPC/GX4000 for now).

Still need to implement USB keyboard, FDC emulation and more...

Of other interesting features:
I can now set hardware breakpoints on code execution and fully monitor all HW regs, probably this will develop into at least doing snapshots on the fly.

Zen80 board ?
This is a planned external version of Galaxy board, but with 8MB SDRAM.
More to come on this, once I am satisfied with the Galaxy board hardware design (hopefully next revision).

EDIT: updated with a few pictures of galaxy board, mounted in a GX4000.

[pelrun]

I can now set hardware breakpoints on code execution and fully monitor all HW regs, probably this will develop into at least doing snapshots on the fly.

Implement a gdb stub on it and that would be an *amazing* device. (well, it already is, but you know, *more*)

[LambdaMikel]

Wow, very cool!
But, in a nutshell - what is a Galaxy Zen80 board?

[Duke]

Implement a gdb stub on it and that would be an *amazing* device. (well, it already is, but you know, *more*)

Maybe - Atleast it would give some way to debug for people wanting to do net applications. Otherwise it's hard to compete with Winape etc for general development.

But, in a nutshell - what is a Galaxy Zen80 board?

Galaxy board is an extended version of M4 board.
It plugs into the Z80 socket on the CPC mainboard and will provide additional features such as RAM expansion & FDC emulation and also ability to plugin wireless USB keyboard & mouse, so you can upgrade a GX4000 console to a very expanded CPC+ without any soldering.
My initial posting on this is lost somewhere in the M4 thread, a basic explanation of the workings is here: http://www.spinpoint.org/2018/04/08/m7-galaxy-board/

Zen80 board pretty much the same, but externally like M4 board. And it will feature 8MB SDRAM (and MCU with more GPIO's),  which would be hard to fit in the internal version without going BGA.

[tjohnson]

Wow this sounds great Duke what is your estimated ETC for these, I would be very interested buying one.

Sent from my E5823 using Tapatalk

[Duke]

Wow this sounds great Duke what is your estimated ETC for these, I would be very interested buying one.

It will be more expensive than M4 board. Probably around 60 euro +/- some, but is very roughly estimated. M7 mcu's are still quite new and pricey in small quantities.
Will give a better estimate in some months when it is closer to being ready

[GUNHED]

Great news! Will the features (except ROM and RAM) also be available for the native CPC-OS?


What exactly do you mean by FDC emulation?

[Duke]

Will the features (except ROM and RAM) also be available for the native CPC-OS?

Yes, they will.

What exactly do you mean by FDC emulation?

It will emulate the FDC765 chip so that any read and write can be redirected to a DSK-image of choice. Think of it like gotek/hxc, except you don't need a floppy disc controller chip in the computer.

[LambdaMikel]

Yeah, I would buy one for sure!

[GUNHED]

Put me on the list too :-) The extenal version I guess, since it can be used for more CPCs by plugging and 8 MB RAM is nice too.


But how do you address the 8 MB? And are they compatible to the 4 MB expansions? The latter one would be really important since this would support already existing 4 MB software. 

[Duke]

Put me on the list too :-) The extenal version I guess, since it can be used for more CPCs by plugging and 8 MB RAM is nice too.

Thanks. I wont take pre-orders yet as I may be dead before it's finished  or have a mental breakdown or whatever else - Once I am closer to be done, I will let you know.

But how do you address the 8 MB? And are they compatible to the 4 MB expansions? The latter one would be really important since this would support already existing 4 MB software. 

I have not decided yet, I will of course make it compatible with what exists already (yarek 4MB I think would be most used?) and add another I/O reg for the additional 4MB and I can even add some config option to the interface if there is more options needed.
I just choose 8MB because SDRAM is ridiculously cheap. I don't think there is much sensible use for it, but if it cost $1 more than 4MB who doesn't want it

[GUNHED]

That's just right    And about the 'more than 512 KB' expansions. Up to now they are all compatible, I mean this expansions:
- Tot0' Y-MEM (enhances to 1 MB via port &7Exx)
- RAM7's 2 MB (enhances to 2 MB via ports &7Fxx to &7Cxx)
- RPalmers 2 MB (enhances to 2 MB via ports &7Fxx to &7Cxx)
- Jareks 4 MB (enhances to 4 MB via ports &7Fxx to &78xx)
- Piotrs 4 MB (enhances to 4 MB via ports &7Fxx to &78xx)

The all do the same using one port address for 512 KB, by decreasing the high-byte they add anothe 512 KB block.

Well, it could be absolutely cool to have a DMA on chip which can transfer inside all the 8 MB RAM :-)

And I really hope you can do finish your two great upcoming boards during one single life 

[Duke]

That's just right    And about the 'more than 512 KB' expansions. Up to now they are all compatible, I mean this expansions:
- Tot0' Y-MEM (enhances to 1 MB via port &7Exx)
- RAM7's 2 MB (enhances to 2 MB via ports &7Fxx to &7Cxx)
- RPalmers 2 MB (enhances to 2 MB via ports &7Fxx to &7Cxx)
- Jareks 4 MB (enhances to 4 MB via ports &7Fxx to &78xx)
- Piotrs 4 MB (enhances to 4 MB via ports &7Fxx to &78xx)

The all do the same using one port address for 512 KB, by decreasing the high-byte they add anothe 512 KB block.

Cool, thanks for the info

Well, it could be absolutely cool to have a DMA on chip which can transfer inside all the 8 MB RAM :-)

It's no problem to transfer within extended memory (fast).
I can add new instructions, like I have 0xed,0x01 for print string to serial console (used for zexall test). 0xed,0x02 for breakpoint to serial console.
However it is more problematic to transfer to base memory, but it's something I would like to add.

And I really hope you can do finish your two great upcoming boards during one single life 

Thanks, me too

[GUNHED]

Thanks a lot for all the info and ideas. Talking about ideas... well, probably dreams, because hardware always has limits. So... sorry for asking... Would it be possible to 'control' the new expansion by software running in ROM too? If not there will be other solutions. 

[Duke]

Would it be possible to 'control' the new expansion by software running in ROM too? If not there will be other solutions. 

Yes, it will feature similar rom board & cartridge slot as M4.
In fact it will be able to map any rom including ROM7 for 6128's (without data contention), and it can map roms similar to gx4000/464 plus/6128 plus on regular CPC.

[GUNHED]

Ok, since the Galaxy board will emulate/simulate/control RAM and ROM ... and it plugs into the CPU socket... would it be possible to run the Z80 with 8 MHz? Just take the Z80H and the CPU will be fine.

I got one 6128 here running at 6 MHz, the whole system is more quick, but it won't work with 8 MHz.

So in case of the Galaxy: Can there be a "switch" to speed up to 8 MHz (or even more) - except for I/O instructions (slower hardware on CPC-PCB?).

Sorry for spamming your thread ;-) It's just an idea I had :-)

[Duke]

Ok, since the Galaxy board will emulate/simulate/control RAM and ROM ... and it plugs into the CPU socket... would it be possible to run the Z80 with 8 MHz? Just take the Z80H and the CPU will be fine.

I got one 6128 here running at 6 MHz, the whole system is more quick, but it won't work with 8 MHz.

So in case of the Galaxy: Can there be a "switch" to speed up to 8 MHz (or even more) - except for I/O instructions (slower hardware on CPC-PCB?).

Sorry for spamming your thread ;-) It's just an idea I had :-)

I have been thinking about that. I even planned to put on a qfp 10 mhz variant to save board space (but couldn't find a suitable, non through hole DIL-40 male connector for the motherboard).
 However, while you could run code quicker from extended RAM (on the galaxy board), the base memory would still need to match the gate array, so it's not much fun without increasing rendering speed.

[GUNHED]

Yes, that's true of course.    However, when developing software for this expansion it could be made in a way to run in simulated RAM (therefore quick). It wouldn't enhance V-RAM access, but calculations a lot. 

[Sykobee (Briggsy)]

This sounds very interesting, I would be interested for my GX4000 (as I have no other Plus hardware).


What are you considering as the GX4000 configuration? 512KB + FDC + Simulated Disk Drive (Gotek compatible? Could you use FlashFloppy and attach an OLED display?) + WiFi/Bluetooth for Keyboard?


Not so concerned about overclocking the CPU TBH, that would be a very niche feature.

[Duke]

What are you considering as the GX4000 configuration? 512KB + FDC + Simulated Disk Drive (Gotek compatible? Could you use FlashFloppy and attach an OLED display?) + WiFi/Bluetooth for Keyboard?

Probably about 320KB + 64KB baseram = 384KB total, maybe I can spare another 64 KB. Will see in the end how much is left.
FDC + disk drive will not be firmware compatible with gotek/flashfloppy/hxc, as it's very different implementation on the FDC level. No display (don't have any spare gpio).
WiFi for network, USB (wireless) for Keyboard & mouse.

[Sykobee (Briggsy)]

Ah, the RAM is within the M7 microcontroller! Still, I think that's plenty for a CPC, not many 512KB RAM games about...

[pelrun]

Well since it doesn't look like I'm going to be able to lay hands on a Plus any time in the foreseeable future, I should start watching for GX4000's now...


(wish I'd got one back when there was a glut... oh well)

[Duke]

Well since it doesn't look like I'm going to be able to lay hands on a Plus any time in the foreseeable future, I should start watching for GX4000's now...


(wish I'd got one back when there was a glut... oh well)

When I started this, you could get a gx4000 for 30-40 euro, so the idea was it would be cheap way to have a fully expanded CPC+.
Prices seems to have gone through the roof now. This goes for regular CPC's too :/

[zhulien]

how about adding an 80Mhz coldfire or similar as per the Microbee?


https://www.ebay.com.au/itm/Microbee-256TC-SE-Special-Edition-Computer-with-Single-drive/332699606762
http://www.microbeetechnology.com.au/store/256tc-se.html

[Duke]

how about adding an 80Mhz coldfire or similar as per the Microbee?

Not sure what the advantage would be over the current setup?