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Re: MSX2 Compatible Computer Project [message #7921 is a reply to message #7920] Sat, 22 August 2020 08:36 Go to previous messageGo to next message
kman is currently offline  kman
Messages: 45
Registered: February 2019
Location: Germany
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> Well, I use the F4 / FMPAC module as a mixer input in OMEGA: U48. I connect the AMP -GND output of the FMPAC to pins 2-4 of U48.

yes you can, but a additional summing-R for U48 is needed: see Summing_R-Network_U48.png

> Is it safe to do this with the circuit you send me?
> What security measure could I take, do I compare the signals with the oscilloscope?

1. you should delete the marked resistor in the schematic: see Modified2_Sound-Interface.png
2. you should measure the amplitude that are feed to the summing network of U48 from the F4/FM-Pack. The amplitude should be in
the same range as from the other sound sources (that simplifies life). Check that the sum of all sources does not overdrive U48
on its output. If the amplitude needs some adjustment, try to adjust R3 & R4. Rxx for U48 should be left as is to keep the
voltage range the same for all inputs.

I have always a bad feeling using elkos when the DC potential on both legs is on the same level (due to the polarized nature of elkos). Check the DC-level on both sides, the (+)-leg should be more positive then the (-)-leg (obvious fact, but this thought is based on some very exciting personal experiences I had during my business life with this ;-) Wink. If this can't be garantieed try to use a film capacitor or two elkos in +][- -][+ series connection.

Kurt

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Re: MSX2 Compatible Computer Project [message #7951 is a reply to message #7921] Tue, 08 September 2020 08:43 Go to previous messageGo to next message
jordi.solis is currently offline  jordi.solis
Messages: 119
Registered: March 2017
Senior Member
Thank you for your answer I didn't saw it until now.
I mentioned that I sue the AMP output, so it includes a resistor and capacitor like in your defined schema, good.
However the mixed sound from the FMPACK was too low and so I increased this by modifying R4 (like your Rxx) to 1k.
I don't know if that was risky but it actually works.
I can compare the current amplitude on the mixer and at the U48 output. Then I will probe what this schema does.
thank you.

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Re: MSX2 Compatible Computer Project [message #7977 is a reply to message #7951] Sun, 20 September 2020 18:38 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
Junior Member
Hi
Another successful build here. Thank you for sharing.
I do have one strange issue. I have built a few cartridges and they seem to function if the rom file is 16K or less. I did see the post about reprogramming the GAL and have done this but the issue remains.
Have tried with PAL and NTSC bios with the same result. As i am yet to get a 32K file that works could somebody be so kind as to share or provide a link to a know good 32k rom file so i can test it.

Many Thanks
John

Update:
The 32k roms I have do work in a emulator but on the Omega

[Updated on: Fri, 25 September 2020 17:47]

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Re: MSX2 Compatible Computer Project [message #8001 is a reply to message #7977] Tue, 06 October 2020 11:56 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
Junior Member
Problem solved.
Seems my lack of MSX knowledge was the issue. Swopping the upper and lower halves of the 32K ROMS solved the issue.

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Re: MSX2 Compatible Computer Project [message #8004 is a reply to message #7977] Tue, 06 October 2020 23:59 Go to previous messageGo to next message
jordi.solis is currently offline  jordi.solis
Messages: 119
Registered: March 2017
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jmannz wrote on Mon, 21 September 2020 03:38
Hi
Another successful build here. Thank you for sharing.
I do have one strange issue. I have built a few cartridges and they seem to function if the rom file is 16K or less. I did see the post about reprogramming the GAL and have done this but the issue remains.
Have tried with PAL and NTSC bios with the same result. As i am yet to get a 32K file that works could somebody be so kind as to share or provide a link to a know good 32k rom file so i can test it.

Update:
The 32k roms I have do work in a emulator but on the Omega
Hi John,
You say you built some cartridges? What schematic did you use?
The problem may be with the connection design you are using. Does the /CS12 signal reach the enable chip correctly?
I have used the schematic of the MSXpi card. With a 32K ROM chip you can activate /CS1 and load a 16K game (first half of memory) activate /CS2 and load another 16K game (second half) or activate the /CS12 signal if you have a game that occupies 32K.
You can compare that scheme with yours to see if there are differences.

regards.

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Re: MSX2 Compatible Computer Project [message #8008 is a reply to message #8004] Fri, 09 October 2020 20:48 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
Junior Member
Hi
Thanks for the reply.
I have vert simple cartridge PCB's with jumpers (No mapper or other chips). the selections are
select CS_1,CS_2 or CS_12 and connect to OE (Pin 22)

With CS_12 connected to Eprom OE (Pin 22) and halves swopped the rom works fine.
as this is a 27C512 I have 2 x 32k roms and can select them by setting A15 low or high

https://github.com/Wierzbowsky/SGC_ImageCreator was the reason i tried swopping the halves

Regards
John

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Re: MSX2 Compatible Computer Project [message #8020 is a reply to message #4137] Tue, 13 October 2020 13:32 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
Hi guys, I'm new here and have also built a working omega. I have recently made myself a copy of The Cure and patched it to work on my hx-10, however it crashes on my omega (both patched and original ROM files) anyone else had this issue?

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Re: MSX2 Compatible Computer Project [message #8026 is a reply to message #8020] Fri, 16 October 2020 20:18 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
Junior Member
@martinmurphy30

What size is your rom file?.
Flick me copy or point me to obtain a copy and I will test it on my Omega.

Regards
John

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Re: MSX2 Compatible Computer Project [message #8027 is a reply to message #8026] Sat, 17 October 2020 06:37 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
Thanks for the reply John, the ROM is 48k and can be downloaded here:https://www.msxdev.org/msxdev-archive/msxdev05/
Will be interesting to see if it works for you.

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Re: MSX2 Compatible Computer Project [message #8029 is a reply to message #8027] Sat, 17 October 2020 15:42 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
Junior Member
The Rom boots with the splash screen and then the next screen "Press fire" I don't have a joystick so no fire to press Smile
Then it restarts with the same sequence. So i can only assume this is normal behavior. This s the rom file as downloaded no patching.

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Re: MSX2 Compatible Computer Project [message #8030 is a reply to message #8029] Sat, 17 October 2020 15:46 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
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Next question.
Has anybody got a TDC:600 floppy controller or clone to work. Mine just goes to a blue screen. I have tried various rom versions all with the same result.
Could somebody be so kind as to test a TDC:600 in the Omega

Many Thanks
John

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Re: MSX2 Compatible Computer Project [message #8033 is a reply to message #8030] Sun, 18 October 2020 09:15 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
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After the press fire screen it should play the video intro and music, if it just restarts then it appears to be some kind of incompatibility with the omega. my copy plays perfectly on my hx-10, but crashes on the omega. Which bios are you using? I'm using a NTSC bios but mite try a pal one to see if it makes any difference.

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Re: MSX2 Compatible Computer Project [message #8034 is a reply to message #8030] Sun, 18 October 2020 09:18 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
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https://msxmakers.design.blog/proyectos/proyecto-tdc-600/
Jordi has tested the floppy controller on his omega and it works fine.

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Re: MSX2 Compatible Computer Project [message #8037 is a reply to message #8034] Mon, 19 October 2020 02:05 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
Junior Member
martinmurphy30 wrote on Sun, 18 October 2020 09:18
https://msxmakers.design.blog/proyectos/proyecto-tdc-600/
Jordi has tested the floppy controller on his omega and it works fine.
Thank you

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Re: MSX2 Compatible Computer Project [message #8038 is a reply to message #8034] Tue, 20 October 2020 07:14 Go to previous messageGo to next message
jordi.solis is currently offline  jordi.solis
Messages: 119
Registered: March 2017
Senior Member
martinmurphy30 wrote on Sun, 18 October 2020 18:18
https://msxmakers.design.blog/proyectos/proyecto-tdc-600/
Jordi has tested the floppy controller on his omega and it works fine.
Thanks

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Re: MSX2 Compatible Computer Project [message #8039 is a reply to message #8038] Tue, 20 October 2020 07:15 Go to previous messageGo to next message
jordi.solis is currently offline  jordi.solis
Messages: 119
Registered: March 2017
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I really had no idea that you were interested in my progress.
I don't know if you can understand or translate my blog. Thanks for your interest.
If someone wants to collaborate and help me by translating the content into English it would be wonderful.
I thought everyone here knew like me or even more.

I intend to extend the omega with FM / MUSIC, Turbo button, a disk drive without wasting a slot, designing a wide case for the extensions, and of course I do not have that much time, any help is welcome.

I would also like to build a BUS monitor cartridge with stop and go, step by step and logic test. Surely it doesn't fit, well on multiple cards.

[Updated on: Tue, 20 October 2020 07:17]

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Re: MSX2 Compatible Computer Project [message #8045 is a reply to message #4137] Thu, 22 October 2020 12:21 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
I'm currently waiting for a few konami mapper prototype PCBs to be delivered, basically a konami PCB using a plcc 512k flash memory. I have a DIY Rom cart finalised which can accept 8k, 16k,32k and 64k eproms. Have been playing with a homebrew beer ide on my hx-10 and was considering making the floppy controller also, but was thinking of a cart with built in gotek. Any interest in this project? Can't decide whether to go the floppy/emulation route, or something like carnivore, sofarom etc...

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Re: MSX2 Compatible Computer Project [message #8076 is a reply to message #8045] Sun, 08 November 2020 04:34 Go to previous messageGo to next message
jordi.solis is currently offline  jordi.solis
Messages: 119
Registered: March 2017
Senior Member
Hi,
I would like to share with all you we are working on a new Acrylic long case for the Omega and even it's a work in progress, I think we almost have it.
of course I will share all designs with the community as soon as we consider it's finished.

https://www.msx.org/node/58752?page=49
https:// www.instagram.com/p/CHVDlVaHUhL/?utm_source=ig_web_copy_link

Kind regards.

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Re: MSX2 Compatible Computer Project [message #8110 is a reply to message #4137] Sun, 29 November 2020 19:20 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
Junior Member
Hi
Anybody made an ASCII mapper cartridge.
I have one based on the schematic below but unfortunately is does NOT seem to work with any of the ACSII roms i have tried.
/forum/index.php?t=getfile&id=1931&private=0

Thanks
John
  • Attachment: acsii.JPG
    (Size: 51.66KB, Downloaded 2528 times)

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Re: MSX2 Compatible Computer Project [message #8112 is a reply to message #8110] Mon, 30 November 2020 09:07 Go to previous messageGo to next message
norwestrzh is currently offline  norwestrzh
Messages: 196
Registered: November 2015
Senior Member
Hi John,

I don't know anything about MSX or "ASCII mapper cartridges", but I have used the 74LS670 quite successfully to interface a 512x8 SRAM to a Z80. It gives either 16k or 32k bank switching capability. Seems to work quite well. If you were using the older version (74LS170), I would suggest pull-ups on the outputs (open collector), but I guess that you are not. I could try to locate the schematics for my Z80 project if you thought that it might help? There was a guy who used this technique quite a while ago, but again, it was to expand the address space of a Z80. I think his name was Gormaker? (I could check that), and he wrote a little article about it. Maybe it is available on line somewhere?

Roger

[I just checked, and the name is Francis Gormarker. There are also schematics of my Z80 project on my Web site -- www.hanscom.us. Look at the "A Simple MMU for the Z80" tab.]

[Updated on: Mon, 30 November 2020 09:25]

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Re: MSX2 Compatible Computer Project [message #8116 is a reply to message #8110] Tue, 01 December 2020 10:22 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
Hi mate, I'm pretty sure that's actually a konami 128k mapper, I think the ASCII carts used a custom chip. Can you try running vampire killer or another konami 128k ROM to see if it works? I made the largest version using 2 74ls670's but so far I've had no luck getting it to work! Laughing

[Updated on: Tue, 01 December 2020 11:51]

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Re: MSX2 Compatible Computer Project [message #8117 is a reply to message #8110] Tue, 01 December 2020 13:16 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
Oops! Sorry hard to make out the chips used there but the konami mapper uses 1 74ls02 and the 74ls670, I see now there's a 74ls32 and possibly a 74ls00 in the schematic you posted. Rolling Eyes

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Re: MSX2 Compatible Computer Project [message #8125 is a reply to message #8117] Fri, 04 December 2020 00:38 Go to previous messageGo to next message
jmannz is currently offline  jmannz
Messages: 9
Registered: September 2020
Junior Member
Hi
Yip i modified the ascii mapper to a Zemina/Konanmi verison with the schematic below and it works perfectly.
Just cant seem to get an ascii verison to work. I know we cant get megarom cartridges but i am going for a single cartridge look and feel.
( The single game cartridge really appeals to me)

The ASCII 8kb has the following mapping: Maybe there's a way to poke the address from basic and confirm the mapper is working correctly
by checking the 74LS670 outputs (ideas welcome)

Bank 1: 4000h - 5FFFh
Bank 2: 6000h - 7FFFh
Bank 3: 8000h - 9FFFh
Bank 4: A000h - BFFFh
And the address to change banks:

Bank 1: 6000h - 67FFh (6000h used)
Bank 2: 6800h - 6FFFh (6800h used)
Bank 3: 7000h - 77FFh (7000h used)
Bank 4: 7800h - 7FFFh (7800h used)


/forum/index.php?t=getfile&id=1932&private=0

Regards
John

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Re: MSX2 Compatible Computer Project [message #8127 is a reply to message #8045] Tue, 08 December 2020 16:56 Go to previous messageGo to next message
jordi.solis is currently offline  jordi.solis
Messages: 119
Registered: March 2017
Senior Member
martinmurphy30 wrote on Thu, 22 October 2020 21:21
I'm currently waiting for a few konami mapper prototype PCBs to be delivered, basically a konami PCB using a plcc 512k flash memory. I have a DIY Rom cart finalised which can accept 8k, 16k,32k and 64k eproms. Have been playing with a homebrew beer ide on my hx-10 and was considering making the floppy controller also, but was thinking of a cart with built in gotek. Any interest in this project? Can't decide whether to go the floppy/emulation route, or something like carnivore, sofarom etc...
I think a cartridge with HxC integrated would be nice.
I'm interested, do you want support?

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Re: MSX2 Compatible Computer Project [message #8139 is a reply to message #4137] Wed, 16 December 2020 15:11 Go to previous messageGo to next message
jordi.solis is currently offline  jordi.solis
Messages: 119
Registered: March 2017
Senior Member
Guys, you would like to know there's a new Omega's case design available.

https://www.thingiverse.com/thing:4686651
cheers.

J. S.
MSXmakers

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Re: MSX2 Compatible Computer Project [message #8141 is a reply to message #8127] Sat, 19 December 2020 04:37 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
Hi Jordi, sorry I have been busy with work/ life recently. I have found a nice layout of the gotek on easyeda, just Google gotek easyeda and you will find it. I was in the process of working out what jumpers would be needed for msx but havent found a definite answer. The floppy controller chips are available in plcc format so it should be possible to build this as a single cart with oled display. As for support, feel free to do what you want I have so many projects on-going I don't know when Il get round to this! But if/when I do I will keep you posted and make any schematics, layouts etc available.

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Re: MSX2 Compatible Computer Project [message #8160 is a reply to message #8125] Wed, 30 December 2020 16:52 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
Hi John, I've attempted to build the zemina/konami mapper again in its simplest form as you posted but I cannot get this to work. Looking at the schematic A14 of the msx cart connector is not connected to anything? Is this correct? I seem to have no luck with msx hardware! Lol!

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Re: MSX2 Compatible Computer Project [message #8191 is a reply to message #8160] Tue, 12 January 2021 12:30 Go to previous messageGo to next message
borutk is currently offline  borutk
Messages: 34
Registered: November 2015
Member
The problem with this mapper is that the translation is not initialized, because RAM has no predetermined initial value on power on.
I guess that on reset, original Konami mapper presets at least translation for 0 and 1.
So you have to first manually initialize at least locations 0 and 1, before you can run anything from the ROM.

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Re: MSX2 Compatible Computer Project [message #8192 is a reply to message #8191] Wed, 13 January 2021 01:33 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
So how would you initialise them manually to get this to work?
Thanks for the reply!

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Re: MSX2 Compatible Computer Project [message #8193 is a reply to message #4137] Wed, 13 January 2021 01:58 Go to previous messageGo to next message
martinmurphy30 is currently offline  martinmurphy30
Messages: 11
Registered: September 2020
Junior Member
Maybe il experiment with pull up resistors to set the bits to a 1 on power up? Any thoughts guys?
Thanks for the reply!

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Re: MSX2 Compatible Computer Project [message #8196 is a reply to message #8193] Fri, 15 January 2021 04:55 Go to previous messageGo to next message
borutk is currently offline  borutk
Messages: 34
Registered: November 2015
Member
Pull ups won't help, the values in the address translation (HC670) RAM are random at powerup.
What you have to do is write a small program that initializes the values in address translator and than do a reset.
Check that your modified mapper works both for reading and writing at the correct addresses.

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Re: MSX2 Compatible Computer Project [message #8700 is a reply to message #8196] Mon, 21 June 2021 07:43 Go to previous messageGo to next message
andrii_kutepov is currently offline  andrii_kutepov
Messages: 29
Registered: November 2015
Junior Member
The project is completely finished. Was to builted and run a long time ago, but lacked little things. That's it now. A few photos for history

https://pic.maxiol.com/thumbs2/1624285911.3280619512.img3979.jpg

https://pic.maxiol.com/thumbs2/1624286038.3280619512.img3985.jpg

https://pic.maxiol.com/thumbs2/1624286083.3280619512.img3986.jpg

https://pic.maxiol.com/thumbs2/1624286114.3280619512.img3987.jpg

https://pic.maxiol.com/thumbs2/1624286140.3280619512.img3988.jpg

https://pic.maxiol.com/thumbs2/1624286176.3280619512.img3989.jpg

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Re: MSX2 Compatible Computer Project [message #8701 is a reply to message #8700] Mon, 21 June 2021 08:30 Go to previous messageGo to next message
tingo is currently offline  tingo
Messages: 114
Registered: February 2017
Location: Oslo, Norway
Senior Member
Beautiful - well done!

Torfinn

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Re: MSX2 Compatible Computer Project [message #8702 is a reply to message #8701] Mon, 21 June 2021 13:28 Go to previous messageGo to next message
lynchaj is currently offline  lynchaj
Messages: 1080
Registered: June 2016
Senior Member
Very nice!

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Re: MSX2 Compatible Computer Project [message #8855 is a reply to message #8700] Thu, 15 July 2021 10:23 Go to previous messageGo to next message
bigpete is currently offline  bigpete
Messages: 7
Registered: May 2020
Junior Member
That case looks fantastic!

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Re: MSX2 Compatible Computer Project [message #9133 is a reply to message #8855] Fri, 17 September 2021 18:21 Go to previous messageGo to next message
ABurrows is currently offline  ABurrows
Messages: 26
Registered: October 2015
Junior Member
Could anyone suggest a link to the case design, or where i would be able to purchase one?

andrii_kutepov wrote on Mon, 21 June 2021 07:43
The project is completely finished. Was to builted and run a long time ago, but lacked little things. That's it now. A few photos for history

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Re: MSX2 Compatible Computer Project [message #10026 is a reply to message #9133] Wed, 20 July 2022 13:28 Go to previous messageGo to next message
jdgabbard is currently offline  jdgabbard
Messages: 76
Registered: March 2016
Member
In the event anyone is looking to build a memory expansion board I redesigned the 4mb memory board. Link to the gerbers is below. This is a much more compact board. But it does require a little skill to solder the SMD components.

https://github.com/jdgabbard/RD-O4MEGA-V1

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

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Re: MSX2 Compatible Computer Project [message #10027 is a reply to message #10026] Thu, 21 July 2022 17:34 Go to previous message
cheshirenoir is currently offline  cheshirenoir
Messages: 14
Registered: June 2022
Junior Member
Nice work Doug! Thanks for sharing.

Chesh

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