This is an old post, preserved for reference.
The products and services mentioned within are no longer available.
First there was the Minstrel 2. Then came the Minstrel 3. Now there is the Minstrel 4......th.
Jupiter Ace port of Dave Stepenson's Tut-Tut. That's been good for testing the hardware along the way.
May the 4th be with you.
2022 Update: Yes, I did go to the effort of launching the Minstrel 4th on May the 4th so I could do that joke. We did a run of Minstrel 4th Final Edition kits last year, and they all sold out quite quickly. It is unlikely there will be any more. At the time of writing, there are still a few Minstrel 2 (ZX80) and Minstrel 3 (ZX81) kits available from The Future Was 8 bit
There are some "Minstrel 4th PCB + programmed parts only" listing available from my SellMyRetro store