*Finally* do it yourself MSX (GR8BIT) released

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By Eugeny_Brychkov

Hero (603)

Eugeny_Brychkov's picture

12-08-2011, 10:33

Hello guys,

I finally released it. Rebranded as GR8BIT.

Site = GR8BIT.RU

I already have some people interested in it, looking forward for more, who are interested for themselves, as gift-makers (for parents, children, friends etc), or for the purpose of improvement of educational process in engineering at the university (college) nearby :)

Your comments are welcome!

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By ro

Prophet (3697)

ro's picture

12-08-2011, 13:26

sweet Smile

By Huey

Prophet (2479)

Huey's picture

12-08-2011, 14:25

Love the name "gr8bit".

By legacy

Hero (570)

legacy's picture

12-08-2011, 15:21

Well,I would like to know more about, and play with.

By lfantoniosi

Supporter (3)

lfantoniosi's picture

12-08-2011, 15:52

I'm interested too. How much for a single-user licence ?

By jltursan

Paragon (1843)

jltursan's picture

12-08-2011, 17:01

Yep, I'm also interested, how much?

Btw, I've some doubts about the info provided:

MSX2+ standard vs V9938 VDP. I suposses that it has a V9938; so it must be a MSX2 really, isn't it?
Composite TV output (grayscale). WHY?, grayscale, I mean...

By Eugeny_Brychkov

Hero (603)

Eugeny_Brychkov's picture

12-08-2011, 17:15

MSX2+ standard vs V9938 VDP. It runs MSX2+ BIOS. V9938 was selected as starting graphics chip intentionally.
Composite TV output (grayscale). Build your own composite converter and insert it into connector on the video board. Or use RGB. Creation of grayscale signal is one of the educational items on processing video signals.

Everyone, please contact me by email, address can be seen in my profile.

By PingPong

Prophet (2579)

PingPong's picture

12-08-2011, 17:27

@Eugeny: so if it run the msx2+ bios, the latter assume VDP V9958. most sw will have malfunctions if relying only on msx version.
to explain better: a sw ask what kind of msx version is :
reply: msx2+
so the sw can assume v9958! and you have only v9938!

was the v9958 not easy to interface in your schematics?

By OeiOeiVogeltje

Paragon (1077)

OeiOeiVogeltje's picture

12-08-2011, 17:53

it shouldn't be that hard to put in a v9958
but this really is a bit confusing ,yes

and
actually MAKING the pcb's is the hardest part,maybe it would be easier to have them made in bulk and send them out to people who want to participate?

By Eugeny_Brychkov

Hero (603)

Eugeny_Brychkov's picture

12-08-2011, 22:52

actually MAKING the pcb's is the hardest part,maybe it would be easier to have them made in bulk and send them out to people who want to participate?
Anyone will help with it? (at least storing PCBs ordered in bulk and doing further distribution). I can't do it because of location.

was the v9958 not easy to interface in your schematics?
I will change specification to MSX2. But it will not change the meaning, value and user/learner experience.

By PingPong

Prophet (2579)

PingPong's picture

13-08-2011, 13:24

was the v9958 not easy to interface in your schematics?
I will change specification to MSX2. But it will not change the meaning, value and user/learner experience.
maybe is better to use a v9958 and leave specs to msx2+. Great gfx...

plus there is a wait line that can be used to 'freeze' the z80 during vdp access.
(I'm not sure however if this work, from tech docs appear that the time needed by the vdp to assert WAIT signal is to high, and maybe the z80 at high clock rate will 'sample' too early the wait pin, seeing a 'no wait' condition )

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