RetroBrew Computers Forum
Discussion forum for the RetroBrew Computers community.

Home » RBC Forums » General Discussion » MSX2 Compatible Computer Project
Re: MSX2 Compatible Computer Project [message #6529 is a reply to message #6527] Tue, 10 September 2019 17:16 Go to previous messageGo to next message
jdgabbard is currently offline  jdgabbard
Messages: 76
Registered: March 2016
Member
Sergey wrote on Tue, 10 September 2019 16:38
Hi Doug,

Nice case... I've initially 3D printed case for my own Harlequin build. It took more than 24 hours if I recall correctly. Unfortunately in my case I had some wrapping on the edges, and it didn't look too good. So eventually I've purchased an injection molded case with the membrane keyboard.
I bet the mechanical keyboard feels nicer and works better than my membrane keyboard Smile

The mainboard size is 150 mm x 330 mm. Perhaps it could be printed in two halves.

Thanks,
Sergey

Sergey,

I followed your build when you did the Harlequin. And saw that you had printed a case, but I don't remember you mentioning the warping. It is a real problem when using abs. This case was printed in PLA. So warping wasn't an issue. However, I do need to finish a bed upgrade on my bed. I started a MK2 upgrade on my Da Vinci Pro. But the supports I printed are not holding up to the bed temp I'd like to maintain. So once that is fixed I plan on trying with ABS.

As for the bed size vs case size, it sounds doable. It'll be a tight fit in halves, but I guess about 150x175 print size would be a ballpark estimate. The case should be fairly easy depending on layout. I'll have to wait until you have boards ready before I could really start drawing anything up. So I'll wait on you to verify it before committing, since you may need to make some changes to layout.

As for the Harlequin keys, they're great! But I don't have any real reference for the speccy, only the ZX81 (more precisely the TS1000). Touch typing is a bit awkward due to the layout of the keyboard. But it's not too terrible. I plan on a slight redesign adding holes for a reset switch and a bank switch for the ROM's A14 line. But other than that, I've very happy with it. I can share the STLs if you're interested. But I'll stop there, as I'm getting pretty far off topic of the thread, and it's only meant as a reference to the fact I enjoy creating things like that.


Doug Gabbard
Creator of the G80-S Micro Computer and 'Porter' of TinyBASIC 2.5g
Website: http://retrodepot.net
z80 TinyBASIC 2.5g: http://retrodepot.net/?p=424
AtariAge Username: jdgabbard
Re: MSX2 Compatible Computer Project [message #6571 is a reply to message #6529] Thu, 26 September 2019 09:32 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Hi,

Here is the project status update:

  • I've received the PCBs.
  • I've compiled a preliminary Bill of Materials
  • I've soldered most of the components, or in case of ICs - sockets, that are required for minimal test configuration.
  • I am waiting for some components from Mouser, as it turned out I haven't ordered everything I need for this project just yet Smile
  • The next steps are to complete that minimal configuration - VDP, Z80, memory, PPI, slot/paging logic, SPLDs, timing logic, keyboard, and test and debug that configuration.
  • Once it is working, I'll gradually add other components: Video circuitry, PSG, slots' buffers, printer control, cassette tape recorder support, and so on.
  • So far I've found a few issues, all related to the silkscreen, they are documented in Known Issues section.
Here is the photo of the board so far:
/forum/index.php?t=getfile&id=1516&private=0

Cheers,
Sergey
Re: MSX2 Compatible Computer Project [message #6572 is a reply to message #4137] Thu, 26 September 2019 09:48 Go to previous messageGo to next message
ajacocks is currently offline  ajacocks
Messages: 15
Registered: November 2015
Junior Member
Looks fantastic, Sergei!

I can't wait to build this machine.

- Alex
Re: MSX2 Compatible Computer Project [message #6575 is a reply to message #6572] Thu, 26 September 2019 11:17 Go to previous messageGo to next message
lintweaker is currently offline  lintweaker
Messages: 69
Registered: April 2018
Member
Hi,

Looks very nice! good luck with testing!
Re: MSX2 Compatible Computer Project [message #6576 is a reply to message #6575] Fri, 27 September 2019 01:14 Go to previous messageGo to next message
andrii_kutepov is currently offline  andrii_kutepov
Messages: 29
Registered: November 2015
Junior Member
It's perfect, like everything Sergey does.
I'm looking forward to the end of the tests.
Already bought a timer and VDP chip on ebay
Re: MSX2 Compatible Computer Project [message #6577 is a reply to message #6576] Fri, 27 September 2019 02:18 Go to previous messageGo to next message
etchedpixels is currently offline  etchedpixels
Messages: 333
Registered: October 2015
Senior Member
Awesome, definitely interested.

And I'm going to have to go finish the MSX1 Fuzix port Cool
Re: MSX2 Compatible Computer Project [message #6585 is a reply to message #6577] Sat, 28 September 2019 05:19 Go to previous messageGo to next message
andrii_kutepov is currently offline  andrii_kutepov
Messages: 29
Registered: November 2015
Junior Member
Sergey,
Please correct the link to the project on the mouser.
Project Access ID:ffffffffff is not correct.

[Updated on: Sat, 28 September 2019 05:19]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6590 is a reply to message #6585] Sun, 29 September 2019 13:34 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Andrii,

The BoM is still changing as I am testing and debugging the board.
Please wait until I have it working Smile

Thanks,
Sergey
Re: MSX2 Compatible Computer Project [message #6591 is a reply to message #6590] Mon, 30 September 2019 10:00 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Hi,

I've spent some a few hours this weekend trying to debug the main board. The process somewhat complicated due to lack of a "printf" output device.
So I had to connect a TIL311 to the printer port instead Smile

/forum/index.php?t=getfile&id=1518&private=0

I found some (really beginner's) mistakes in the schematic:


  • 74*32 pinout was incorrect... well, not exactly incorrect. It was correct for "De Morgan" normal symbol (positive logic OR), but incorrect for "De Morgan" convert symbol (negative logic / NAND with inverted inputs). As the result there's 11 OR gates that have 22 incorrect connections. I had to patch my system, cutting multiple traces and soldering a bunch of wires. The funny thing is that I am using a custom library exactly because while ago KiCad library had some pinout issues.
  • Swapped /RD and /WR lines in the subslot register read/write decoder. "Fortunately" the fix didn't require cutting additional traces... the traces were already cut while fixing the previous issue. I just had to re-solder a couple of wires.
/forum/index.php?t=getfile&id=1519&private=0

After fixing these issues the system seems to get stuck at enumerating expanded slots. That's the next thing to debug.

Also, the right angle keyboard header seems to interfere with printer port latch. Gotta use straight header instead...

Thanks,
Sergey

[Updated on: Mon, 30 September 2019 10:05]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6592 is a reply to message #6591] Mon, 30 September 2019 11:43 Go to previous messageGo to next message
lintweaker is currently offline  lintweaker
Messages: 69
Registered: April 2018
Member
Nice progress, do/did you use a logic analyzer? I found it a very useful tool debugging where the system gets stuck and seeing the board actually executing Z80 code.
Re: MSX2 Compatible Computer Project [message #6593 is a reply to message #6592] Mon, 30 September 2019 15:52 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
I do have a mixed signal oscilloscope. I didn't have to use the logic analyzer on this board just yet.
Oscilloscope on the other hand was quite useful in the initial troubleshooting.
Now the board is fetching and running the code from ROM.
I still have to determine if the issue that I am seeing now is related to RAM access. The RAM implementation in MSX2 is quite complex - it involves two slot decoders (primary and expanded) and paging.
Re: MSX2 Compatible Computer Project [message #6599 is a reply to message #6593] Tue, 01 October 2019 10:52 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Found another silly issue... Apparently V9938 VDP /INT output is an open drain output, but I don't have a pull-up on it. As the result it reads as "LOW", which causes an interrupt right after the first EI instruction. That's why it was getting stuck at, or rather at the end of enumerating expanded slots subroutine.
Re: MSX2 Compatible Computer Project [message #6601 is a reply to message #6599] Tue, 01 October 2019 11:20 Go to previous messageGo to next message
lintweaker is currently offline  lintweaker
Messages: 69
Registered: April 2018
Member
Ha! good catch! My board has a pullup on the /INT line on the Z80 end so I never encountered that issue (your design allows for a seperate /INT from the slots as it should, my design omits the feature)
Does slot enumeration now work? It sounds like your getting close on MSX bootup...You can always try to boot MSX1 which is a bit simpler
Re: MSX2 Compatible Computer Project [message #6602 is a reply to message #6601] Tue, 01 October 2019 11:30 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Yes, the slot enumeration seems to work. It worked before too. It just there is an EI at the end of the slot enumeration.
Frankly, I am not quite sure why check_expanded subroutine in C-BIOS has an DI/EI around it.
The interrupts are disabled anyway at reset. The first instruction of C-BIOS is DI. And they get enabled later on.
And check_expanded is only called during the initialization. They could have saved two bytes on these DI/EI! Smile

I'll connect a pull-up to VDP later today, and will continue working on debugging the board.

On an unrelated note, I am wondering how useful the printer port is... Perhaps I should replace it with a WD37C65 FDC?

[Updated on: Tue, 01 October 2019 11:32]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6603 is a reply to message #4137] Tue, 01 October 2019 12:24 Go to previous messageGo to next message
martin8bity is currently offline  martin8bity
Messages: 21
Registered: October 2015
Location: Kurim
Junior Member
Great to see, that it becomes alive. I think the FDC could be more useful than a printer port, if it will fit on board.

www.8bity.cz
Re: MSX2 Compatible Computer Project [message #6606 is a reply to message #6603] Tue, 01 October 2019 14:58 Go to previous messageGo to next message
etchedpixels is currently offline  etchedpixels
Messages: 333
Registered: October 2015
Senior Member
The FDC on an MSX machine normally goes in a cartridge. It's usually memory mapped at 0x4000 with the cartridge 16K space holding the MSXDOS and the MMIO for it just to ensure that combined with subslots it's as painful as possible to program - like all MSX it was designed by a sadist who hated programmers ;)

Alan
Re: MSX2 Compatible Computer Project [message #6608 is a reply to message #6606] Tue, 01 October 2019 15:30 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Right... potentially it is possible to map the FDC itself to the I/O space (instead of memory), and use one of the subslots for the Disk ROM. My design allows mapping Flash ROM to any subslot.
More work though, as I'll need to disassemble one of these WD37C64 Disk ROMs and replace all the MMIO LDs with IN/OUT.
Re: MSX2 Compatible Computer Project [message #6612 is a reply to message #6608] Tue, 01 October 2019 19:57 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Good news are that after connecting a pull-up to VDP /INT the system no longer getting stuck at EI.
In fact according to my POST display it boots all the way and gets stuck not finding any ROMs to boot from.
The not so good news are that I still don't have any display.
Nothing on V9938 VDP RGB and VIDEO pins. There's ~127 kHz signal on CSYNC and HSYNC instead of expected ~14.59 kHz. Also the /INT frequency is about 250 Hz instead of expected 60 Hz.
I am wondering if C-BIOS doesn't initialize VDP correctly (e.g. skips initializing some essential registers)?
I've checked the VDP wiring, compared it to other designs and I haven't find any issues. I also checked that chip select is generated, and in fact I can even see VDP writing to VRAM, apparently when BIOS is clearing the screen.

[Updated on: Wed, 02 October 2019 11:21]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6615 is a reply to message #6612] Thu, 03 October 2019 11:52 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
It boots!

/forum/index.php?t=getfile&id=1526&private=0

Well, kind of. It appears that VDP does get configured properly once in a while (every 5th attempt or so).
I still haven't figured out why it doesn't get configured properly other times.
I had a suspicion that /RESET gets asserted for too short time. Although, according to ADM693 datasheet the reset is active for 200 ms, and according to V9938 datasheet it needs only 10 ms reset pulse.
I've also tried connecting VDP /RESET to the RS flip-flop that deactivates slot selection at power on, which gets reset the first time PPI is accessed. That didn't seem to help. So it might not be the RESET after all.
Another suspicion is power supply. I use 5 V / 2.5 A regulated wall type power supply. It might be that the voltage drop is too big.... Anyway, that's the next thing I am going to check.
I'd appreciate any ideas on this VDP issue.

Other than that I've spent some time ironing out the SYNC signal generation. On V9938 CSYNC is a "three level" signal. This actually means that the logic low is about 2.8V and logic high is about 4.8V. CXA1645 encoder expects TTL level sync signal. So I had to re-purpose Q2 and use one of optional 74HCT04 gates to generate the proper SYNC signal.
/forum/index.php?t=getfile&id=1524&private=0

For the folks that want to use RGB output. Any idea what HSYNC level in this case should be? It appears that VGA has a TTL level sync. If that's true, I can just output the SYNCIN to the RGB connector...

Cheers,
Sergey
Re: MSX2 Compatible Computer Project [message #6617 is a reply to message #6615] Fri, 04 October 2019 00:21 Go to previous messageGo to next message
lintweaker is currently offline  lintweaker
Messages: 69
Registered: April 2018
Member
Good to see that familiar screen!
I am not sure if the V9958 is different wrt CSYNC. I am also using the CX1645, I did not encounter issues with SYNC.

Excerpt from my video board:
https://slimnet.home.xs4all.nl/v9958-cx1645p-excerpt.png

[Updated on: Fri, 04 October 2019 00:30]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6618 is a reply to message #6617] Fri, 04 October 2019 00:48 Go to previous messageGo to next message
martin8bity is currently offline  martin8bity
Messages: 21
Registered: October 2015
Location: Kurim
Junior Member
Try different 9938/9958. I do not know the source, but there is a lot of the second quality ICs on eBay, that have peculiar problems.

www.8bity.cz
Re: MSX2 Compatible Computer Project [message #6621 is a reply to message #6618] Fri, 04 October 2019 06:41 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Jurgen:
My CSYNC level shifter works just fine. I assume it will also work with V9958, although in this case it is possible to bypass it. I am wondering if you're outputting the sync signal(s). And if so, what signals and voltage levels (e.g. VGA needs both VSYNC and HSYNC in TTL levels, SCART uses composite sync at 0.7V or so level, but apparently it can get sync from composite video too)

Martin:
I've tried 3 VDPs. I believe I bought them in three different opportunities from different sellers. I also think that I bought them from US and not China. All behave similarly.

Some other updates:
- The boot success rate is better than I thought. So I can "reliably" boot the system from the second or the third try... Might be a power thing, although I haven't tested that just yet.
- I found yet another silly error. This time in PSG clock divider... I've got /CLK and D inputs swapped on a 74HCT74
- And yet another (not so silly) PSG issue... I've used a single power supply op amp for the filter, and it needs a virtual ground (2.5V signal). I've connected a real ground instead. The sound output is not working as the result.
- The slots work! At least that Vampire Killer cartridge that I have plays nicely Smile
- It had been brought to my attention that the slot connectors need to be rotated 180 degrees. That would require some considerable board rerouting.

That's all for this morning.
Have a great weekend!
- Sergey

Re: MSX2 Compatible Computer Project [message #6622 is a reply to message #6621] Fri, 04 October 2019 08:05 Go to previous messageGo to next message
lintweaker is currently offline  lintweaker
Messages: 69
Registered: April 2018
Member
Sergey wrote on Fri, 04 October 2019 15:41

Jurgen:
My CSYNC level shifter works just fine. I assume it will also work with V9958, although in this case it is possible to bypass it. I am wondering if you're outputting the sync signal(s). And if so, what signals and voltage levels (e.g. VGA needs both VSYNC and HSYNC in TTL levels, SCART uses composite sync at 0.7V or so level, but apparently it can get sync from composite video too)
I am not using a 'real' VGA output. I do not have a VGA monitor that still works with a 15kHz signal, although I use a VGA connector for output with RGB and COMP as sync signal. I can switch COMP between composite video and VDP csync.
With the VGA connector I am using a VGA-to-SCART cable which has an additional USB connector for the switch signal. This then goes to a cheap SCART to HDMI converter. An other option is a VGA 'scan doubler'.

[Updated on: Fri, 04 October 2019 08:09]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6625 is a reply to message #6622] Fri, 04 October 2019 21:16 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Meanwhile I've fixed the sound. And kids are already enjoying this thing 😊
https://youtu.be/P6nD6vv4WaA

Jurgen: I have an 8 pin Mini DIN connector for everything video and audio. I suppose I'll add composite video there along with RGB.

[Updated on: Fri, 04 October 2019 21:20]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6644 is a reply to message #6625] Wed, 09 October 2019 17:23 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Yet another update. I've fixed the issues I found so far, and I rerouted the PCB to rotate cartridge slots 180 degrees. This actually also simplified the routing, as I didn't have to route the data bus all the way to the right side of the board.
Other changes include swapping DB25 printer connector to MSX standard Micro Ribbon 14-pin connector (aka Centronics).

I would really appreciate if few of you would take a look at the schematic and the PCB design, and report any issues you'll find.

Latest updates are on GitHub: https://github.com/skiselev/omega/blob/master/Mainboard.md

I'll also will do a few more checks, and also test the joystick and cassette recorder functionality on my v1.0. And then I'll order another set of PCBs.

Thanks,
Sergey
Re: MSX2 Compatible Computer Project [message #6645 is a reply to message #6644] Thu, 10 October 2019 06:48 Go to previous messageGo to next message
martin8bity is currently offline  martin8bity
Messages: 21
Registered: October 2015
Location: Kurim
Junior Member
Did you find the "boot success rate" or "VDP initialization" issue reason?

www.8bity.cz
Re: MSX2 Compatible Computer Project [message #6646 is a reply to message #6645] Thu, 10 October 2019 09:13 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
martin8bity wrote on Thu, 10 October 2019 06:48
Did you find the "boot success rate" or "VDP initialization" issue reason?
Kind of. It is definitely power related. First of all it seems that 5 x 47 uF bypass capacitors on 5V rail is a bit too much. This causes the voltage to ramp-up slowly, especially given that I use a 5V "wall wart" type of power supply with a fairly long cable. I've removed all these capacitors, except the one closest to the power jack. Now board boots almost 100% of the time. And if it doesn't a short off/on fixes the situation.
Next, the power supervisor which I am using (ADM693) has a typical reset voltage of 4.4 V, while VDP shows minimal voltage of 4.75 V. I've ordered ADM691 instead, which has a higher reset voltage of 4.65 V. The 0.1 V difference hopefully is not a big issue, since there is a delay between power reaching 4.65 V and reset signal.
Re: MSX2 Compatible Computer Project [message #6722 is a reply to message #6646] Wed, 30 October 2019 00:56 Go to previous messageGo to next message
bifo is currently offline  bifo
Messages: 48
Registered: October 2019
Member
Very excited to build this project when everything is finalized. I've got boards for an N8 and a Harlequin 128 to build in the meantime, but an MSX2 has been a holy grail computer for me for a long time.
Re: MSX2 Compatible Computer Project [message #6724 is a reply to message #6722] Wed, 30 October 2019 09:46 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
One more update. Yesterday I went ahead and ordered version 1.1 PCBs. This version fixes all the known issues found so far, and hopefully it won't introduce any new ones Smile
The GitHub repository has been updated with the new design files. I also have updated the documentation. Of course it can use more work, as for example it doesn't really describe how to generate Flash ROM images.

I'll build and test the board once I get the PCBs - probably some time next week.
Re: MSX2 Compatible Computer Project [message #6725 is a reply to message #6724] Fri, 01 November 2019 02:16 Go to previous messageGo to next message
lintweaker is currently offline  lintweaker
Messages: 69
Registered: April 2018
Member
Nice! You've been busy Smile

I am busy with my very first MSX cartridge, if it works it could make a nice companion for the Omega. The cartridge can be used as a (virtual) disk drive using a Rasperry Pi Zero as master.
The boards just arrived yesterday, I'll put one together this weekend...fingers crossed it works...

BTW the project is based on smbaker's "Raspberry Pi Virtual Floppy for ISA (PC XT/AT) Computers"

Added a picture of the current state:
/forum/index.php?t=getfile&id=1557&private=0

[Updated on: Sat, 02 November 2019 02:20]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6738 is a reply to message #4137] Fri, 08 November 2019 00:17 Go to previous messageGo to next message
bifo is currently offline  bifo
Messages: 48
Registered: October 2019
Member
I was just poking around on ebay checking the prices on 9938s, and for some reason they're significantly more expensive than 9958s. The 9958 isn't pin compatible but the modification is apparently relatively simple (it's an extremely common upgrade), but I was wondering why you chose the 9938 over the 9958?

Of course, it is entirely possible that we've created a small price bubble in anticipation of building this board. Very Happy
Re: MSX2 Compatible Computer Project [message #6739 is a reply to message #6738] Fri, 08 November 2019 12:16 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Quote:
I was just poking around on ebay checking the prices on 9938s, and for some reason they're significantly more expensive than 9958s. The 9958 isn't pin compatible but the modification is apparently relatively simple (it's an extremely common upgrade), but I was wondering why you chose the 9938 over the 9958?
The Omega board actually supports both V9958 and V9938 VDPs. And I personally would recommend V9958 over V9938 because it provides better video quality, and has some additional (MSX2+) features.
Re: MSX2 Compatible Computer Project [message #6740 is a reply to message #6739] Sat, 09 November 2019 03:08 Go to previous messageGo to next message
bifo is currently offline  bifo
Messages: 48
Registered: October 2019
Member
Another question: Given that the owner of the MSX standard has agreed that it's all freely available, and said that you owe a $1 debt to Microsoft for using MSX basic (i defy you to find someone in microsoft who would not turn around and say 'we don't need your dollar'Wink, what obstacle is there for you for providing a generic compatible MSX2+ bios? Just don't brand it with the MSX logo.
Re: MSX2 Compatible Computer Project [message #6741 is a reply to message #6740] Sat, 09 November 2019 16:04 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
Quote:
what obstacle is there for you for providing a generic compatible MSX2+ bios?
I don't really feel like getting into a legal hurdle with Microsoft and whoever owns the MSX stuff now. So I don't plan to distribute MSX2 BIOS or BASIC. The open source alternative (C-BIOS) is available. Also there are plenty of places on the internet one can get MSX2 ROMs. I plan to provide a script to create the ROM image using either one of these options.

Quote:
Given that the owner of the MSX standard has agreed that it's all freely available
In an interview to someone? There is no official statement. There's no place where MSX binaries or source code had been officially released.

Quote:
you owe a $1 debt to Microsoft for using MSX basic
Where do I put that dollar? But seriously. I personally don't feel like I owe anything for using 30+ old piece of software for recreational and non profit purposes, that hasn't been a money maker for the company for at least 25 last years. Yet, it is quite possible that some patent troll representing MSX will go after me, just because there is "MSX" string somewhere in the binaries.

[Updated on: Sat, 09 November 2019 16:37]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6742 is a reply to message #6741] Sat, 09 November 2019 16:31 Go to previous messageGo to next message
Sergey is currently offline  Sergey
Messages: 236
Registered: October 2015
Location: Portland, OR
Senior Member
I have some good news: I've built and tested Omega Mainboard v1.1, and it is working properly.

/forum/index.php?t=getfile&id=1563&private=0

I made many updates to the documentation, including the bill of materials. Please read it, and the next "Configuration options" session carefully before ordering parts. Let me know if you have any questions or comments.

For those of you who expressed an interest in building Omega, I have a dozen extra PCBs available for $20 each. With that being said I am traveling next week and I won't be able to mail anything. So please hold on your orders until I am back (November 16th).

/forum/index.php?t=getfile&id=1564&private=0
/forum/index.php?t=getfile&id=1565&private=0
Re: MSX2 Compatible Computer Project [message #6743 is a reply to message #4137] Sat, 09 November 2019 17:13 Go to previous messageGo to next message
jdgabbard is currently offline  jdgabbard
Messages: 76
Registered: March 2016
Member
Sergey,

That looks great! Looks like I have something to build in the not too distant future!


Doug Gabbard
Creator of the G80-S Micro Computer and 'Porter' of TinyBASIC 2.5g
Website: http://retrodepot.net
z80 TinyBASIC 2.5g: http://retrodepot.net/?p=424
AtariAge Username: jdgabbard
Re: MSX2 Compatible Computer Project [message #6744 is a reply to message #6742] Sat, 09 November 2019 22:10 Go to previous messageGo to next message
pbirkel is currently offline  pbirkel
Messages: 61
Registered: October 2015
Member
Very nice! PM sent with my PCB request, when you return :-}.
Re: MSX2 Compatible Computer Project [message #6746 is a reply to message #6741] Sun, 10 November 2019 00:49 Go to previous messageGo to next message
bifo is currently offline  bifo
Messages: 48
Registered: October 2019
Member
Quote:
Quote:
Given that the owner of the MSX standard has agreed that it's all freely available
In an interview to someone? There is no official statement. There's no place where MSX binaries or source code had been officially released.
Given that this project is 'build-your-own' and in theory teaches people how the various parts work with each other, you should drop a line to the man who did the interview and try to get in touch with Nishi-san himself. I think this project would tickle his fancy.

Frankly, we should let him know about all of what retrobrew does, I think he'd appreciate the existence of a place like this, a community of old school hackers.

[Updated on: Sun, 10 November 2019 00:52]

Report message to a moderator

Re: MSX2 Compatible Computer Project [message #6747 is a reply to message #4137] Sun, 10 November 2019 01:00 Go to previous messageGo to next message
bifo is currently offline  bifo
Messages: 48
Registered: October 2019
Member
now I want to call microsoft and ask them where i can send my dollar
Re: MSX2 Compatible Computer Project [message #6749 is a reply to message #6747] Mon, 11 November 2019 04:53 Go to previous messageGo to previous message
jordi.solis is currently offline  jordi.solis
Messages: 114
Registered: March 2017
Senior Member
Hi people.
there's another MSX project witch you can buy to Eugeny Brychkov who includes MSX official license.
maybe you can ask him.
here you are the project: http://www.gr8bit.ru/what-is-gr8bit.htm
Previous Topic: New Dragon 64 clone
Next Topic: Building an Apollo Guidance Computer


Current Time: Thu Mar 28 22:14:14 PDT 2024

Total time taken to generate the page: 0.01299 seconds