There have been many project to create a storage interface for ZX spectrum like SMART card, DivMMC, ZXMMC, DivIDE . .. .. ..
This version will firstly focus on make an DIY version for SD/MMC card that give you the ability to play all you spectrum game selected from a menu.
The design is simple an is the first or a series SD/MMC interfaces for other hardware platforms. Plans are for ZX81, Dragon 32, Oric, MSX.
This version will use a standard Kempston joystick interface, a Boot/menu ROM and the SD/MMC interface.
Target price for a complete system is less 150Nkr or €17. Depending on if it will be external or internal.
When ready, I hope to add this to the Dlouhy Doors Inc. and Harlequin project.
Principle is as following.
1.Boot from external 16KB ROM.
2.Read menu for SD card as present to user with choose to select program or jump to native machine.
3. Load file to memory from SD card
4. Create switch routine in ram and switch to program
Kempston joystick interface
Enable/disable boot ROM
You will find the layout as is processes here.
Version 2 is available, simplified without address decoding
Pictures of the prototype.
Hope to find some volunteers to help with the code.
Sources for information:
23 thoughts on “ZXcard DIY SD/MMC interface”
Added new version with siplifyed IO address decoding.
Will add reset button and enable/disable of boot rom.
This project looks fine.
The Eprom have any special Rom?
Im interested to do one home made pcb.
The eprom need software.
I haven’t had the time to do that, but maybe now is the time.
Will order some board to test it.
Nice to ear that.
I will proceed to do the home made pcb meanwhile.
I forgot to comment I will proceed with Versión 2 pcb.
Your tests with be with that versión?
Yes, the test vard will be version 2.
David K Knab
Do you have the rom code to implement this expansion? I haven’t seen it anywhere.
Not too easy for home made pcb but not imposible. Additional work will be need to separate some closed tracks.
It could helps small change in some tracks, they are too closed.
Still following this Project. 😉
I just got the prototype board this week.
Have started to write test code for the card. Så fare only 2 mistakes.
Needed to insert a diode from the flip flop to ROMCS. Could not force ROMCS low only force hi.
If small changes to be done understood no problems. I have to update my pcb.
Layout/pcb already updated?
If you want I can send you the current PCB free of charge.
The PCB and schematic are not updatet yet.
Will add some pictures of the prototype board.
If you want to send me one pcb, pls send to my email.
Pls contact to my email address and we speak for more details.
I do not understand, it does not work yet, because the software in ROM is not done yet ? ..or ?
I would love to makeup One for muito old Spectrum Machine!!!!
Dos you finished the Eprom code?
Thanks certo, very mutch, 😀
I was wondering if u could finish ur project. It’s really nice!
Is it working? Could u update ur PCB schematics?
Will do that. 🙂
David K Knab
Do you have the rom code for this expansion?
Did you manage to get this project working – with the software for the onboard EPROM?
I’m interested in buying or building one of these?
PS: Why is it that every time I post a reply here, it is deleted??
Hi, will start on this again. 🙂
Did you finished the ROM content?
I love this project!!
Hi, Has anyone done anything about the rom for this project as it would make a great diy project.
Many Thanks in advance.
Hi, I have not made the ROM yet. But will start again on this.