AX-230 photos/ROMs - How to update WiKi and BlueMSX?

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By Tabajara-Labs

Expert (90)

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12-06-2018, 16:02

Hello All!

Just got an AX-230 from my good friend Paulo Maluf and there will be a post on tabajara-labs.blogspot.com later.

I already took many internal/external photos, wrote something about the circuit, read the two roms (one 128K being used as 64K and one 1mb with the internal software, using a LZ93A13 megarom mapper)

How do I add this info to the WiKi, and send to BlueMSX team to add this machine to the pool?

Thanks
Alexandre

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By mars2000you

Enlighted (5413)

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12-06-2018, 16:20

You can contact me by using the MRC contact form on my profile.

By mars2000you

Enlighted (5413)

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12-06-2018, 18:12

Thanks to Tabajara-Labs, I've succeeeded to build a config of this machine for blueMSX. It will be soon available on the Resource page of the blueMSX website.

The MRC Wiki will also be updated. I need to make a choice with all the pictures I've received from Brazil.

By Tabajara-Labs

Expert (90)

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12-06-2018, 18:29

I think I'll retake the motherboard bottom photo. It needs to be better focused and better resolution. Will do ASAP

By mars2000you

Enlighted (5413)

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12-06-2018, 19:52

It seems me a good idea.

By Tabajara-Labs

Expert (90)

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12-06-2018, 22:24

An interesting update analysing the circuit of AX230.

Pin 134 of the T7937A MSX engine is /clock - a clock output for the slots. On this AX230, it is a clock INPUT from a generator with a 74HC02 and an unmarked crystal (I'll measure here, but I bet 3.579545MHz). Of course, the output of this generator is also directed to the slots. So, MAYBE the engine is overclocked and an external clock is used for the slots, OR this higher master frequency is used to create the correct color signal for the composite output (I don't know what video color system is used on the country of this computer) and a correct NTSC subcarrier frequency oscilator is used to keep compatibility with the standard.

Since the engine doesn't have a datasheet avaiable, I bet this can be configured as input or output by software, but I have no way of attesting it

By Manuel

Ascended (14983)

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12-06-2018, 23:00

Can you share the information so I can create a configuration for openMSX as well?

By Tabajara-Labs

Expert (90)

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12-06-2018, 23:15

Sure Manuel, here you are
https://www.dropbox.com/s/1yepcqm0lvd4ivm/MSX%20AX230%20phot...

Anyone who needs it, feel free to download.

By Manuel

Ascended (14983)

Manuel's picture

13-06-2018, 00:07

So, what is in these 2 ROMs? The first 32kB of IC125 seems to be normal BIOS/BASIC, but what about the last 32kB?
It seems to be calendar like stuff for the 3rd 16kB block. The 4th one is "Sakhr BASIC". How are these last 2 mapped into the slot system?
And what kind of mapper is that LZ93A13? ASCII 8kB?

By Manuel

Ascended (14983)

Manuel's picture

13-06-2018, 00:25

Hmm, the slot map on the Wiki isn't consistent with the MSXMEM2 output.
MSXMEM2 (and the box) says 64kB RAM in slot 3-0 and a ROM in slot 1-0. Seems consistent with the AX170. But as I said: how is this ROM spread over the slots?
Tabajara-Labs: can you do a 64kB dump of all slots and subslots (except the cartridge slot)?

Does this machine have an external slot 2 where you had a MegaFlashROM SCC+ SD or something in? Or what am I looking at, in your slot 2?

By Tabajara-Labs

Expert (90)

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13-06-2018, 01:47

Yes Manuel, I was using a SD/Mapper on slot 2. I can do whatever you feel like, just instruct me how to do, I'm not very knowledgeable about these MSX programs Smile
BTW, the machine only has 32K of RAM, this is something me and Mars2000you still haven't figured out how. The memory chip is a 32K PSRAM one.

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