Author Topic: SD card interface (Read 313062 times)

Zozosoft · « **Reply #165 on:** 2014.May.12. 11:29:03 »

Is it possible to add a jumper for EP64/128 selection? Many people have both types.

Z80System · « **Reply #166 on:** 2014.May.12. 11:34:35 »

Quote

I should add the only reason that the memory needs to be at F8-FB is because of "naughty" programs just assuming that these memory pages are available.

In this case that would be the simplified approach (for plain users like me) if there would be a jumper, or something like that, and the different type of cards would be mapped at different places by default,

and if somebody want one of the card assembled currently mapped from f8 (because of EP64 case, or anything), then that jumper would be connected on a specific card. only for that card, what the user want to map from f8. multiple jumper connection at multiple cards is a collision and not supported ...

or somthing like this ...

Saint · « **Reply #167 on:** 2014.May.12. 11:38:11 »

Quote from: Zozosoft

Is possible add jumper for EP64/128 selection? Many people have both type.

Possibly, but not with the current PCB. I don't have any lines free on the GAL to be able to use as an input to alter the address decoding at the moment. But I could reduce the precision of the address decoding a little (from 256 bytes to 512 bytes) and add a jumper to set the spare pin high or low which would alter the address decoding. This would certainly be the best option for future revisions.

For most collectors, in the UK at least, a fixed memory mapping for the Enterprise 64 would be enough. So I can quite happily sell these boards to people who don't have the need for moving the memory address, and get some new boards made up with the jumper for those who need it.

Z80System · « **Reply #168 on:** 2014.May.12. 11:39:25 »

Of course, the inside expansion cards already done, cannot have this feature ... but at the pluggable expansions maybe the need is bigger for flexibility ...

gflorez · « **Reply #169 on:** 2014.May.12. 17:29:46 »

We must talk(better suggest) about the future of the interface. Saint has mentioned it will be an all in one expansion, usable for all the EP users, not conflicting with older expansions.

If the 64k users memory problem had been discussed earlier , now Saint could have an easy solution.

He had mentioned his expansion card has space for more upgrading, and I think now is the time to propose things.

There are some obvious improvements yet made in the nineties of the past century....by the Mészáros team, easy to implement as they already have EXOS extensions or utilities(Zozotools), like Real Time Clock, Serial port(mouse) or Keyboard adapter, but what the EPs need more is real connexion with other computers or directly to the WEB. Now that the storage problem seems to be fixed....

Now is the time when every EP user can reach by few money that future the creators promised us but rarely was perceived on all that years.

But we must talk about it, please.

lgb · « **Reply #170 on:** 2014.May.12. 18:25:02 »

I know this is my boring idea again and again, but is it possible somehow to have some kind of solder points at least for external SPI bus usage besides the SD card? And of course the ability to choose SPI target between SPI external and SPI towards the SD card. As far as I know SD cards are not so nice players in the SPI game, so simply having to select signals for the two "targets" are not enough.

At least I've read somewhere that SD cards sometimes not so nice to release the MOSI, MISO signals even if there are not selected, or very to slow to leave it/them floating ... But then it would require an external buffer/etc to really disconnect it from the SPI bus or having totally seperated SPI buses for the SD card and the external SPI bus (but that require extra pins from the CPLD to be used). Well, since not so many people are interested (I guess) I am not sure if it's worth to deal with this ....

Saint · « **Reply #171 on:** 2014.May.12. 22:04:54 »

Quote from: lgb

I know this is my boring idea again and again, but is it possible somehow to have some kind of solder points at least for external SPI bus usage besides the SD card? And of course the ability to choose SPI target between SPI external and SPI towards the SD card. As far as I know SD cards are not so nice players in the SPI game, so simply having to select signals for the two "targets" are not enough. At least I've read somewhere that SD cards sometimes not so nice to release the MOSI, MISO signals even if there are not selected, or very to slow to leave it/them floating ... But then it would require an external buffer/etc to really disconnect it from the SPI bus or having totally seperated SPI buses for the SD card and the external SPI bus (but that require extra pins from the CPLD to be used). Well, since not so many people are interested (I guess) I am not sure if it's worth to deal with this ....

I have already brought a 2nd SPI device to a 6 pin header for people to use other SPI devices. I'm not sure about SD cards not playing nice, though. If their CS is deselected, they should set MISO to high impedance...

lgb · « **Reply #172 on:** 2014.May.13. 00:24:34 »

Quote from: Saint

I have already brought a 2nd SPI device to a 6 pin header for people to use other SPI devices.

Cool

Quote

I'm not sure about SD cards not playing nice, though. If their CS is deselected, they should set MISO to high impedance...

Yes, they should ...

And btw about the "useful other SPI device", I am still thinking on the ENC28J60. Even a ready-to-use module with RJ45, PCB etc costs about 4$ or so on ebay, as far as I can remember. But I should stop say these again and again as I will be banned off the forum soon

Zozosoft · « **Reply #173 on:** 2014.May.13. 09:45:38 »

Another configuration problem which is need to be handled:
With original machines using EXOS 2.0/2.1, 512K ROM can't be used, only two programs detected at x0h segments. And the RAM test with lot of RAM are also painful slowly

Solutions:
a) Upgrade onboard EXOS to 2.3+ version. But not all user can do it, and many machine which are nice, unopened don't wanted to open it.
b) Need a cartridge with cartridge version of my quick RAM test. Least additional ROM chip needed, but possible whole cartridge (if not want to modify original).
c) Decode interface ROM to cartridge address space (then 04h-23h area used), then possible run the quick test from the interface. Then do not use cartridge

It is another GAL program variation.

Saint · « **Reply #174 on:** 2014.May.13. 10:36:35 »

Quote from: Zozosoft

Another configuration problem which is need to be handled:
With original machines using EXOS 2.0/2.1, 512K ROM can't be used, only two programs detected at x0h segments. And the RAM test with lot of RAM are also painful slowly
Solutions:
a) Upgrade onboard EXOS to 2.3+ version. But not all user can do it, and many machine which are nice, unopened don't wanted to open it.
b) Need a cartridge with cartridge version of my quick RAM test. Least additional ROM chip needed, but possible whole cartridge (if not want to modify original).
c) Decode interface ROM to cartridge address space (then 04h-23h area used), then possible run the quick test from the interface. Then do not use cartridge It is another GAL program variation.

Ah, right. So I'd need to map the FLASH ROM to the cartridge space. That's ok, I can do that. Is there any problem with having the FLASH mapped there in all versions? As if you want a cartridge, you can just use the flash manager to install it...

Also, is it possible to check and execute all ROM slots with older EXOS using a cartridge extension? Rather than just the 0-7 then x0-x3. It would be a shame to waste a lot of the 512K FLASH with older EXOS.

Zozosoft · « **Reply #175 on:** 2014.May.13. 10:43:39 »

If it is mapped to the cartridge, then install my memory test program to 04h. It is can detect all ROMs.

Saint · « **Reply #176 on:** 2014.May.13. 10:51:38 »

Quote from: Zozosoft

If it is mapped to the cartridge, then install my memory test program to 04h. It is can detect all ROMs.

NoP · « **Reply #177 on:** 2014.May.13. 15:18:20 »

Count me in, too. I need one for my unmodified, unopened 128k German Enterprise computer. Also, I do not have any spare cartridges, so for me the ideal solution would be the one Zozo mentioned (mapping cartridge area into your expansion).

Saint · « **Reply #178 on:** 2014.May.13. 15:27:26 »

Yes, the whole point of this expansion for me is giving everyone out there the ability to run all EP software straight from one plug and play device.

lgb · « **Reply #179 on:** 2014.May.13. 17:24:41 »

Quote from: Saint

Yes, the whole point of this expansion for me is giving everyone out there the ability to run all EP software straight from one plug and play device.

Just I miss the "like" button now

Author Topic: SD card interface (Read 313062 times)

Zozosoft

Re: SD card interface

Z80System

Re: SD card interface

Saint

Re: SD card interface

Z80System

Re: SD card interface

gflorez

Re: SD card interface

lgb

Re: SD card interface

Saint

Re: SD card interface

lgb

Re: SD card interface

Zozosoft

Re: SD card interface

Saint

Re: SD card interface

Zozosoft

Re: SD card interface

Saint

Re: SD card interface

NoP

Re: SD card interface

Saint

Re: SD card interface

lgb

Re: SD card interface