Sunday 27 February 2022

Minstrel Final Edition Kits

At the end of last year, I put together as many Minstrel 2, 3 and 4th kits as I could. The limiting factor was availability of parts. An increasing number of parts are out of stock everywhere, and the stock situation does not seem to be improving. Microchip appear to have a rolling 12 months estimate for most of their microcontrollers and EPROMs. RAM, voltage regulators, and logic chips then started to go out of stock and it became difficult to complete any of the kits.

These kits are sold via The Future Was 8 bit, I am very grateful to them for doing that, as it has been able to keep me going through these difficult times. 

We have branded them Final Editions, as these are the last of this sort of kit we are likely to be able to make for the foreseeable future.

To celebrate that, I wrote a nice new manual. Each of the kits feature a newly written 100 page spiral bound manual covering building and testing of all the kits.

I understand TFW8b may be offering remaining stocks of these manuals for sale separately for existing Minstrel owners. 

When I used to sell these myself, I had all sorts of options, but I have no practical way of shipping or dealing with all the import / export duties etc. as the UK is a bit broken at the moment. To keep things simple, there is a set menu with a few options.

Kit A) Minstrel 2 with Keyboard

This is a ZX80 compatible computer kit. 3.25MHz Z80, 16K of RAM and an integrated 40 key keyboard. This has the option of running the original ZX80 4K integer BASIC, as well as the later ZX81 style 8K floating point BASIC. It comes with keyboard overlays for both versions of BASIC.

This follows the ZX80 design, using TTL chip, with a few updates. The ROM and RAM are more modern single chips, and the voltage regulator is a switch mode 7805 replacement. There is also one additional TTL chip and some extra circuitry to generate a more compliant monochrome composite video that the ZX80 originally did.

The minimalistic design meant that the Z80 spent most of it's time drawing the screen, and when it had to run any code, it would stop drawing the screen. It does not support the ZX81 mode where some code is run during the blank portions of the screen, but many games use similar code to achieve 'flicker free' graphics. Read more about How the ZX80 Works.

Kit B) Minstrel 3 with Keyboard

The second option is the Minstrel 3, this is a ZX81 compatible computer kit. 3.25MHz Z80, 32K of RAM and an integrated 40 key keyboard. This runs 8K floating point BASIC and supports the NMI controlled fast and slow modes, to allow code to run whilst the blank bits of the screen are being drawn, to avoid the flickering when keys are pressed that the ZX80 suffered from.

This is a new design with improved video output and support for various high resolution graphics modes so you can try out new games pushing the limits of the ZX81.

As well as old favourites.

HC logic chips are used throughout, so the current consumption is about half of the ZX80 and the 7805 regulator can be used without a heatsink. Read more about the design of the Minstrel 3.

Note this version does not include the Minstrel ZXpand, and those are not available separately. 

Kits C and D

These kits were released when this blog was offline, so unfortunately the other two kits have now sold out. I do not expect to be able to make those again, so I am afraid that is the end for the Minstrel 3 + ZXpand and the Minstrel 4th.

At the time of writing, there are still some Minstrel 2 and a few Minstrel 3 kits left, so if you want one of those, I would get over to The Future Was 8 bit now and order one.

There are new kits in development, I hope that by the time they are ready to go, parts availability will have returned to a better state and I will be able to start making kits again.