Sinclair ZX80 / ZX81 / Z88 Forums

https://youtu.be/zVnGZ1Purzs

https://codeberg.org/Retrostuff/SD81-Booster

I open list to see possible interested people for a run of SD81 Booster

The estimated price (assembled) is €50 55€ without case and €65 70€ with case + shipping and will be paid in advance to finance the purchase of components.
I will do an initial batch with the first 10 interested people at the estimated price and with the experience of the first 10 I will recalculate the price for the next ones, although it should not go far.

The interface will not incorporate the speaker part, although it will have a jack to connect to the TV or an amplifier.
The reason is, the sound quality is much better with an external amplifier and probably I will remove the speaker from the project in a short.

That said, I open an interest list.



EDITED: I have added the possibility to buy only PCB including only CPLD + regulator already soldered (18€20€)


1. oldcomput no case (Vdr) - Paid - Sent
2. Benkenobi no case (Vdr) - - Sent
3. IgnacioMonge+case(Rw) -Paid - Sent
4. sinclair200+case (Vrd) - Paid - Sent
5. Paul + case (SZXW) - Paid - Sent
6. billloguidice + case (SZXW) - Paid - Sent
7. garillete + case. (Rw) - Paid - Sent
8. retrolab no case (Vdr) - Paid - Sent
9. zx4ever (RW) - Paid - Sent
10. Pedro Gimeno + Case - Paid - Sent

11. Ron + case (RW) - Paid - Sent
12. esposiblegames + case (Vdr) - Paid - Sent
13. Dim_75 + case (SZXW) - Paid - Sent
14. Mikes + case (Vdr) -Paid - Sent
15. jupiterjones (Vdr) + case - Paid - Sent
16. hsimpson (SZXW) + case - Paid - Sent
17. Rampa69 (telegram) + case - Paid - Sent
18. AndiZX81 (SZXW) no case - Paid
19. Trevor_B (SZXW) no case - Paid
20. papalapa + case (RW) - Paid Sent

21. Iturbez no case (Vdr)
22. Edzard (SZXW) + case
23. muon + case (RW) - paid - Sent
24. 1024MAK + case (SZXW) -Paid - Sent
25. Exile + case (SZXW) - Paid - Sent
26. amauget + case (SZXW) - Paid - Sent
27. Dancresp + case (RW) - Paid - Sent

only PCB + CPLD +3v3 regulator soldered (estimated 18€)
1. cacharreo (Vdr) -Paid - Sent
2. Paul (SZXW) - Paid - Sent
3. alvaroalea (Vdr) Paid - Sent

List of tested software:
https://codeberg.org/Retrostuff/SD81-Bo ... %20list.md

Looks very interesting. Looking forward for more.

Blimey! Looks amazing!

The teaser is too short ! More, more, more !

In my opinion the teaser is far to long considering the amount of information in it.
Where is the website and what are the technical details?
And what will it cost?

Also if made abroad will it be shipped to the UK?

Moggy wrote: ↑Wed Jun 28, 2023 7:44 pm Also if made abroad will it be shipped to the UK?

Or to the EU?

Paul wrote: ↑Wed Jun 28, 2023 7:37 pm In my opinion the teaser is far to long considering the amount of information in it.
Where is the website and what are the technical details?
And what will it cost?

Our plans are to make the repository public with all the technical information shortly.
Basically what is missing is completing the documentation.
I have no plans to release it for sale, maybe some initial batch, but the idea is to publish all the information so that everyone can assemble it by themselves or make batches freely.
Everything will be public, both the software and the hardware and the firmware of the CPLD.

Some advance:
The main components are:
- An ATMEGA 2560
- One CPLD XC95XL144
- A 512KB RAM chip
- Some additional discrete chips

It uses a command-based communication that allows the ATMEGA to communicate with the Z80 using the CPLD as an intermediary.
The sound is based on an AY emulator running on the ATMEGA.
Allows you to program the CPLD by copying an XSVF file to the SD card.
Alternative ROMs can be loaded from SD using the BASIC LOAD command.
The M1NOT/MC45 mod can be activated and deactivated by software and does not require any internal modification of the zx81.
It is compatible with pseudohires, WRX, and CH$128 without hardware mods.
Memory is paged in 8KB blocks and all pages can be set to any block.

As I said, at first we will try to make a batch so that interested users who do not have the skills to assemble it themselves can enjoy it.
There would be no problem sending it to any part of the world, but of course the shipping cost will be higher the further away from Spain.
The price should be calculated, but we do not intend to do business with this.

I hope that's enough, for now.

Thanks a lot for these informations.
That sounds very promising. I'm looking forward to discover how you changed the Basic commands and how all these electronic parts play together.
It's great to see so much develepment for our loved doorstopper.
2023 is going to be a great year for the zeddy.
Cheers Paul

It is a pleasure to inform you that we have finally made the repository public.

https://codeberg.org/Retrostuff/SD81-Booster