Minstrel 2 ZX80 Compatible Computer Built and Tested (Blue for ZX81 Case)

This is a built and tested Tynemouth Software Minstrel Issue 2 computer. The Minstrel 2 is a Z80 based 8 bit computer which is compatible with the original ZX80. It sticks to the original design, the only changes being 16K of RAM and a composite video output with a backporch signal that was missing on the ZX80 and early ZX81s. It can run the original ZX80 4K BASIC or the later upgrade 8K BASIC. The power input jack has been changed to a 2.1mm DC jack (as used on the ZX Spectrum), with positive or negative polarity (jumper selectable).

Note it follows the ZX80 design, so although it can run ZX81 software with the 8K BASIC ROM, it lacks the fast/slow mode of the ZX81 so cannot run any ZX81 software which requires this (including most games). If you want full ZX81 compatibility, see the Minstrel 3.

The PCB is the same form factor as the ZX81, so this build is designed to fit in an original ZX81 case and use the original (or a modern replacement) membrane. (note the video out connector is in a different place on the TS1000, so those cases are not suitable withtout modification). The Minstrel 2 can also be built for stand alone use, let me know what you want and I will see what I can do.

This auction is for a built and tested mainboard only. No ZX81 membrane, case, cablse or power supply are included. The Z80 CPU, ROM and RAM are socketed, but all the other ICs are soldered directly.

This is the updated V2.7 PCB with improved video circuitry, in blue. This version is fitted with a 7805 switching regulator so it runs cool and no heatsink is required.

See other listings for a complete kit and a built and tested version, and also keyboard overlays with the ZX80 colour scheme with 4K and 8K BASIC keywords.

More information on my blog:

http://blog.tynemouthsoftware.co.uk/2017/01/minstrel-zx80-clone-issue-2.html

Minstrel Build Instructions v2.7.pdf [1362,23] KB