Help hacking and restoring AX-350II sakhr

Página 9/18
2 | 3 | 4 | 5 | 6 | 7 | 8 | | 10 | 11 | 12 | 13 | 14

Por gdx

Enlighted (5503)

Imagen del gdx

06-03-2018, 08:08

I think the 41464 Rams are usable instead of the LH2464 but note it's better to use same models and same speed in the same device. So if you use 41464, replace too the old Rams. I think 100ns is OK but if you can, it's better to take 120ns as the old ones to make sure it works.

"ali6x944" wrote:

Also can I upgrade my machine to MSX2+? Or even just replace the video chip I have?

This is possible but look for a tutorial because it's not enough to just replace the VDP. This requires some modifications.

Por Wild_Penguin

Hero (644)

Imagen del Wild_Penguin

06-03-2018, 23:27

I need to reply here because I gave a bit misinformation previously about removeing keycaps: they do come off (the SM was right).

However it is very difficult, you need to remove the mechanism first from the plate and then pull very straight and very hard on the keycap. Here are some details.

My recommendation: If you want to stay sane: Don't. Remove. The. Keycaps.

Or, don't dismantle the mechanisms (unless you really need to / have a good reason to, such as a non-workable keyboard because, of, say, sand inside the mechanisms, as I did). The process is very time consuming and tedious.

About RAM upgrade: Put sockets in the empty places while doing the mod. That way you can test with different models of (compatible) chips. They could just work as they should be compatible, and if they do, hey, you win! If you run into problems, remove old chips (and replace them with sockets) so you can put identical chips in. Even if you are a soldering god, there's always some risk in removing chips (and it is more difficult than just cleaning otherwise empty holes).

There is other good reasons for using sockets; the chips you order online might be faulty.

Por ali6x944

Master (197)

Imagen del ali6x944

07-03-2018, 09:37

Wild_Penguin]/About RAM upgrade: Put sockets in the empty places while doing the mod. That way you can test with different models of (compatible) chips. They could just work as they should be compatible, and if they do, hey, you win! If you run into problems, remove old chips (and replace them with sockets) so you can put identical chips in. Even if you are a soldering god, there's always some risk in removing chips (and it is more difficult than just cleaning otherwise empty holes).

There is other good reasons for using sockets; the chips you order online might be faulty.

Quote:
[quote=gdx

wrote:

I think the 41464 Rams are usable instead of the LH2464 but note it's better to use same models and same speed in the same device. So if you use 41464, replace too the old Rams. I think 100ns is OK but if you can, it's better to take 120ns as the old ones to make sure it works.

I see your point about the ram, but looking at the datasheets for both chips makes me think shorter read write cycles can be handled by the z80 , see this:
http://www.piclist.com/techref/mem/dram/slide4.html
Also both parts are pin to pin compatible and have similar specifications regarding input capacitance and read or write periods...
I can't but assume it will be fine from what I have read, but I am not 100% sure about it, because in the example used in the link above the z80 is running at 4MHz not 3.58MHz as I assume is running in the computer..

Por Wild_Penguin

Hero (644)

Imagen del Wild_Penguin

07-03-2018, 11:51

I'm not a chip/semiconductor/msx expert. but my reasoning is that any memory chip that meets the minimum requirements should work. It doesn't matter if they are not the exact same type, since the cpu does not care if some chip is ready or not. Just don't use too slow RAM, and everything should work.

Por ali6x944

Master (197)

Imagen del ali6x944

07-03-2018, 14:22

Wild_Penguin wrote:

I'm not a chip/semiconductor/msx expert. but my reasoning is that any memory chip that meets the minimum requirements should work. It doesn't matter if they are not the exact same type, since the cpu does not care if some chip is ready or not. Just don't use too slow RAM, and everything should work.

This is good, will order some of the chips then, thanks Smile

Por ali6x944

Master (197)

Imagen del ali6x944

07-03-2018, 15:25

also I found some guy selling samsung SFD-321B 1.44MB FDDs locally here in saudi , and I would like to know if I can Hack them or not before I buy them, see datasheet:
https://drive.google.com/file/d/1kzuTwLoi3bmP8qyZtbnw88jamas...

Por ali6x944

Master (197)

Imagen del ali6x944

07-03-2018, 17:16

another selling what looks like sony MPF920Z 1.44MB FDDs locally here in saudi , again I would like to know if I can Hack them or not before I buy them, see datasheet:
https://drive.google.com/file/d/10nwr6CHruIpJsFqC2NojEX0HstM...

Por ali6x944

Master (197)

Imagen del ali6x944

07-03-2018, 17:18

I think the sony would be a better candidate for the hack, because a lot people seem to modify it for their Amigas...

Por ali6x944

Master (197)

Imagen del ali6x944

08-03-2018, 10:03

Did anyone find resources about how to hack these for the msx?

Por rderooy

Paladin (686)

Imagen del rderooy

08-03-2018, 11:27

ali6x944 wrote:

Did anyone find resources about how to hack these for the msx?

There is a bunch of MSX FDD mod guides here:
http://msx.hansotten.com/do-it-yourself/msx-floppy-drives/

Unfortunately most of them are not in English.

Página 9/18
2 | 3 | 4 | 5 | 6 | 7 | 8 | | 10 | 11 | 12 | 13 | 14