Electron SD Interface & SW Ram Expansion

[Ramtop]

Good to hear it worked for you

Little update: I'm now offering tracked shipping to the EU as some people have requested it. Also, I've been testing an ElkSD64 build of MMFS2 (which does away with the need for a beeb.mmb file) and will knock up something for download if there's interest in it. Obviously MMFS2 is still experimental and may be buggy, and it breaks game menus, but it's fun to play with.

[0xC0DE]

Count me in!

[retromarky]

Hi
Are these still available please?
I'd like one if so

Kind regards
Retro Marky

[Ramtop]

Yes, I still have a couple left. Use the 'contact us' button at the bottom of the page to ask the mods for PM access then send me a PM and I'll get one sorted out for you.

[dicesare]

Good morning for everyone,
I'm new user, I can't contact Gary (Ramtop) via PM.
I'm proud owner of an Acorn Electron and searching for a mass storage solution different from Plus 3 and disk.
So I found this marvellous SD Interface (with plus RAM exp).
If you can contact me I'm interested for one interface shipped in Italy
Thanks

Claudio

[1024MAK]

Hi
Are these still available please?
I'd like one if so

Kind regards
Retro Marky

Good morning for everyone,
I'm new user, I can't contact Gary (Ramtop) via PM.
I'm proud owner of an Acorn Electron and searching for a mass storage solution different from Plus 3 and disk.
So I found this marvellous SD Interface (with plus RAM exp).
If you can contact me I'm interested for one interface shipped in Italy
Thanks

Claudio

Hello Retro Marky and Claudio

Welcome to StarDot

You may wish to say hello in the introduce yourself section.

The ability to reply to, or to send Private Messages (PMs) is disabled for new members at first. However you can ask for full PM functionality to be enabled by using the ‘Contact us’ link (envelope icon) at the bottom of every page. This sends a message to the admin’s who will consider your request. They are more likely to enable full PM functionality if you demonstrate that you are a friendly member. So please do consider telling us about yourself and your hobbies in the introduce yourself section.

Mark

[bigheaduk]

Hi Ramtop,

Do you have any of the SD card readers left for sale, postage to UK? I've recently joined the forum so don't yet have the ability to PM (I have requested, but that was only the other day).

Regards,
Adam.

[Ramtop]

If you can't get PM access, drop me an email at my username @gmx.co.uk and we'll get an ElkSD64 sorted for you.

[Barnabas]

Hi Gary,

Just emailed you as I don't seem to have a PM option (although that might just be me being dim).

[Ramtop]

You're not being dim at all

The PM option isn't enabled until you have 25 posts on the forum. I got your email and have replied.

[joemorgan]

Hey!

I'm Interested on it.

Please, how could i get one?


Thanks in advance!

[Ramtop]

Just the same as above, drop me an email at my username @gmx.co.uk

[bigheaduk]

Received and playing with it, many thanks!

[Barnabas]

I have to say thanks for this - received the interface this morning and I've just been trying some games which all seem to be working fine!

The Electron was my first computer - my original machine went as a hand-me-down to my cousins when I got an Amiga in 1991. I bought a Master a couple of years ago, but using the Electron again is pure nostalgia for me. In the past week I've picked up a new Elk for £30ish which has cleaned up perfectly and is now working fine after a re-seating of the ULA and clean of the keyboard connector. I'd forgotten what a great little computer it is and it's so much smaller than I remember it as well (probably because I'm much bigger )

[Ramtop]

Glad to hear you both got your interfaces ok.

The Elk is a funny machine. I don't have any history with it, for me the 80s were filled with various Sinclairs and Commodores, and there were plenty of better specced machines even BITD, but I find myself using it more than any of my other 8-bit machines.

[owen2471]

Hello do you have any interfaces left. And how much ? Thanks

[iddod]

well, i'm annoyed at myself...
i ordered one of these the other day via ebay for £40... it didn't occur to me to check here first, and now i have i see they're £30... bugger! that'll learn me!

[Ramtop]

Oops!

If it's any consolation, sales on EBay are what funds development of new designs. So you've helped make sure I'll be able to keep releasing new stuff for the Electron in future.

[iddod]

ace, I don't feel as bad knowing that..

[riscyrobot]

Hi Ramtop.
Could you pm me if you still have any available?
Cheers,
-Riscy.

[hicks]

Oops!

If it's any consolation, sales on EBay are what funds development of new designs. So you've helped make sure I'll be able to keep releasing new stuff for the Electron in future.

I just did the same was about to cancel and order via you here until reading the above and realising it's your account selling them. Enjoy the bonus Hopefully it can be shipped before lockdown starts

Out of interest, IF a card is bricked due to a bad flash update or uploading a game into the ROM rather than RAM and getting stuck with it auto-booting. Is there any way recover from this even if it requires some extra hardware to reflash things directly? I've no idea about the hardware used in this as I didn't see any schematics available and obviously don't have the device yet to take a look.

[Papalapa]

Oops!

If it's any consolation, sales on EBay are what funds development of new designs. So you've helped make sure I'll be able to keep releasing new stuff for the Electron in future.

I just did the same was about to cancel and order via you here until reading the above and realising it's your account selling them. Enjoy the bonus Hopefully it can be shipped before lockdown starts

Me too.. but after reading that eBay sales benefits are invested in new ElkSD 64 developments (maybe a split ROM/RAM bank for MMFS ) I'm happy.

[Ramtop]

Out of interest, IF a card is bricked due to a bad flash update or uploading a game into the ROM rather than RAM and getting stuck with it auto-booting. Is there any way recover from this even if it requires some extra hardware to reflash things directly? I've no idea about the hardware used in this as I didn't see any schematics available and obviously don't have the device yet to take a look.

With a bricked card there's not much an end user can do, other than send it back to me to be recovered (which I do for free, they just have to pay return postage). Recovery involves destroying the ElkSD's case as it is glued together and made of brittle PLA that shatters when pulled apart, desoldering a flash chip with tiny 0.5mm pitch pins, flashing a new chip and soldering it down, and then gluing on a new case. So it's not trivial.

I've never been happy with this, but everything about the ElkSD64 is the way it is in order to keep the cost down. Moving to a socketed chip and a screwed together case would add to the cost and increase build time, which also in the end causes a price increase. When designng it I felt, and still feel, it's important for Electron owners to not have to pay more than Speccy or C64 users for a memory card interface, even though those machines benefit from economies of scale the Elk can't match.

Not much of a secret that I'm working on a big brother for the ElkSD64 at the moment. As there's less price pressure on this design it'll ship with a socketed PLCC flash chip, although the initial cases will be glued - the screw-together case is not at the point where I can print it in quantity yet, so at first a simpler glued case will be used. The ElkSD-Plus 1 cartridge also has a screwed case and will transtion to a socketed flash chip once my stock of PCBs runs out.

(and yes, absolutely my big thanks to everyone who buys from me on EBay - that really does fund work on stuff like the upcoming ElkSDxxx and Electron Turbo Card.)

[hicks]

Thanks for the details, I've soldered 1.27mm pitch (DRV8805) but never tried anything smaller, so I'll just have to avoid breaking it

Reading through the manual this bit has me wondering:

Do NOT load such games into a sideways ROM bank, as the game may take over the Electron at boot time and prevent any other use whenever the ElkSD64 is connected, effectively bricking the interface card.

If that were to happen, would it not be possible to block the Electron booting from ROM in the same way you do with other physical roms when using a plus1. Press CTRL+Break then wait about a second and hit escape? Obviously I'm not willing to test out that question given the card just arrived and I don't fancy having to send it straight back to you but I'm curious both whether it works and if not, what prevents it.

One more follow up question. Page 14 that holds the MMFS ROM. Is there any protection in place to avoid writes to that?

The ElkSD64 arrived today just in time for the start of lockdown and works a treat. < 7s to load a game that was taking 5+ minutes is great.

[sP1d3r]

Not much of a secret that I'm working on a big brother for the ElkSD64 at the moment. As there's less price pressure on this design it'll ship with a socketed PLCC flash chip, although the initial cases will be glued - the screw-together case is not at the point where I can print it in quantity yet, so at first a simpler glued case will be used. The ElkSD-Plus 1 cartridge also has a screwed case and will transtion to a socketed flash chip once my stock of PCBs runs out.

Hi I was wondering if it'd be possible to use an adapter pcb to convert an ElkSD64 into the Plus One version, e.g. a pcb that slots into the ElkSD64 which fits in a cartridge slot?

[Ramtop]

If that were to happen, would it not be possible to block the Electron booting from ROM in the same way you do with other physical roms when using a plus1. Press CTRL+Break then wait about a second and hit escape? Obviously I'm not willing to test out that question given the card just arrived and I don't fancy having to send it straight back to you but I'm curious both whether it works and if not, what prevents it.

Never tried that, so no idea if it works - I should probably do some investigating of methods to recover from this situation, if I get the time to do so. But my advice remains not to flash game ROMs.

One more follow up question. Page 14 that holds the MMFS ROM. Is there any protection in place to avoid writes to that?

The flash utility is hard coded to bank 15 only, so it will only ever flash that bank. Only the MMFS update utility will flash bank 14. And initiating a re-flash of the SST39SF010 chip that the ElkSD64 uses is quite complex, so there's zero chance of an accidental overwrite due to a crash or whatever.

The ElkSD64 arrived today just in time for the start of lockdown and works a treat. < 7s to load a game that was taking 5+ minutes is great.

Glad you're enjoying it!

[Ramtop]

Hi I was wondering if it'd be possible to use an adapter pcb to convert an ElkSD64 into the Plus One version, e.g. a pcb that slots into the ElkSD64 which fits in a cartridge slot?

Sadly, no. The devices are quite different and there would be numerous problems involved. One example: the ElkSD64 design requires access to the sideways paging register at &FE05, but the cartridge slots do not pemit access to the &FExx page. The ElkSD64 also uses four sideways pages, while cartridges slots only have two pages available per slot.

The expansion slot is much more flexible than a cartridge slot, so a device compatible with both would need to be designed from the ground up wil dual use in mind.

[sP1d3r]

Just wondering something I've noticed about my ElkSD64 is that the composite video output is improved in much the same way as an AP6, the colour output isn't smudged looking or blurry.

[polluks]

Maybe Prince of Persia should be possible?
See https://github.com/kieranhj/pop-beeb