Yamaha MSX2 upgrade

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By Alexey

Guardian (1796)

Alexey's picture

01-05-2018, 23:54

Just bought the Yamaha for upgrading it to MSX2+, but decided not to go all the way, because I already have the similar 2+ in my collection. I also have the untouched MSX2. Finally I decided to patch the BIOS and leave the old VDP. What was done:

- changed the default font (it is now like in MSX2+, much better looking - see the image below)
- changed the keyboard layout so that the numbers are input without a Shift http://podrezov.com/msx2up/yis503iii_basic-bios2_special.rom
- in the EPROM with Subrom I still have the CPM, but later will replace it with something useful, for example FMPAC BIOS http://podrezov.com/msx2up/yis503iii_msx2sub_cpm.rom
- installed the FMPAC/F4 module, the original Z80 CPU was carefully desoldered and put on top https://github.com/RBSC/F4-FMPAC
- installed 1Mb module designed by Kamil Karimov https://github.com/Wierzbowsky/Yamaha_RAM
- installed the SFG clone into the side slot https://github.com/RBSC/SFG_Clone
- installed the new video board with S-Video and better Composite video https://github.com/RBSC/YamahaVideoBoard

So in the end I got a nicely upgraded MSX2. :) Still thinking of getting a 7MHz upgrade... Also thinking of modifying the BIOS to show the real amount of RAM.

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By Manuel

Ascended (14888)

Manuel's picture

02-05-2018, 00:25

What is that font? Don't know why you said it's like the MSX2+, because the font of all MSX generations is identical (except for a few region specific characters).

By Alexey

Guardian (1796)

Alexey's picture

02-05-2018, 01:35

Didn't know that. I cut this font out of the MSX2+ BIOS that we used in our YIS503III 2+ upgrade. I believe this BIOS is a modified version of a Sony's or Panasonic's BIOS for their MSX2+ models. But probably the font was replaced there already.

By Alexey

Guardian (1796)

Alexey's picture

04-05-2018, 02:57

Here's the custom MSX2 subrom test with the working RAM counter (borrowed from MSX2+ subrom) and the awesome MSX logo effect made by Nyyrikki. Now I need to figure out how to make custom images...

https://www.youtube.com/watch?v=qB6rl8jfsGE

By sdsnatcher73

Master (233)

sdsnatcher73's picture

04-05-2018, 06:10

Very cool, also how the text appears as if it were typed! Funiest thing: the image youtube chose as a preview has the text printing unfinished, without the 1024Kbytes. So my first thought: working RAM counter? There is no RAM value...

By alexito

Master (234)

alexito's picture

04-05-2018, 18:16

That is an AWESOME SPLASH SCREEN for sure.

Wink

By Meits

Scribe (5226)

Meits's picture

04-05-2018, 19:20

I guess it's one of Nyyrikki's boot screens (scroll a bit)

By ToriHino

Master (249)

ToriHino's picture

04-05-2018, 19:29

Meits wrote:

I guess it's one of Nyyrikki's boot screens (scroll a bit)

Yes it is ;) :

Alexey wrote:

...the awesome MSX logo effect made by Nyyrikki...

By Meits

Scribe (5226)

Meits's picture

04-05-2018, 20:38

Yeah, I see... I didn't read everything Wink
I should've written 'probably one of these' Running Naked in a Field of Flowers

By Alexey

Guardian (1796)

Alexey's picture

05-05-2018, 00:27

I found out what could be useful inside the custom subrom... Smile

https://www.youtube.com/watch?v=qCJwKXcSDD0

Also the right alignment of the text was adjusted to be always the same regardless of the amount of the detected RAM. The file is here:

http://podrezov.com/msx2up/yis503iii_msx2sub_special.rom

Will test this ROM on the real MSX2 during the weekend.

By Alexey

Guardian (1796)

Alexey's picture

05-05-2018, 20:41

Verified to be working on a real YIS503III machine.

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