OpenSpand announcement

[nollkolltroll]

Paul: your offer of parting with a ZX80 is very generous, but I believe the Minstrel 2 and TL801 I own will be enough for testing on my side. I try really hard to not buy any more old computers...

Paul is also invited to my (currently) private github repo that hosts all the code and schematics/PCB stuff.

[Lardo Boffin]

As a well-known cummudgeonly judge on a popular ballroom dancing-based television show would say - A-MAZ-ING!

Hello Charlie! Hope all is well?

[nollkolltroll]

Moggy: I've implemented the rom selector now and tested Big Bang X2. The scroll speed alone is worth it! Very nice to have as an option, though I will do my testing on the Tomte rom to get consistent results that I can compare to a real ZXpand+.

[nollkolltroll]

ZX80 update: I tried the OpenSpand on my Minstrel 2 and it started as expected. LOAD and SAVE worked. Joystick to keyboard injection does not work, as exected. Just a very quick test to whet the appetite

[Paul]

ZX80 update: I tried the OpenSpand on my Minstrel 2 and it started as expected. LOAD and SAVE worked. Joystick to keyboard injection does not work, as exected. Just a very quick test to whet the appetite

Joystick injection should work when original keyboard is connected via open collector IC not Standard Driver.
On ZX80 I just pull the IC

(Same with any external keyboard like memotech etc

[Moggy]

As a well-known cummudgeonly judge on a popular ballroom dancing-based television show would say - A-MAZ-ING!

Who woke you up!?

[Moggy]

Moggy: I've implemented the rom selector now and tested Big Bang X2. The scroll speed alone is worth it! Very nice to have as an option, though I will do my testing on the Tomte rom to get consistent results that I can compare to a real ZXpand+.

Excellent news Adam.

[David G]

This is a sweet project. I like that it doesn't use any FPGA/GAL/CPLD


And before this I thought 48 GPIO ought to be enough for anybody


The Raspberry Pi microcontroller RP2350 has 520 KB RAM
The 2350 stamp XL adds 16MB flash

[nollkolltroll]

Before the release of rp2350, I really hoped for more ram and 64 gpio. What we got is very nice, but _I_ could certainly use more gpio!

[Mustermann]

I know a little about Minstrel 3.

It is using 2x 74HC257 for keyboard input. This part is not an open collector chip as the ZX81 ULA is. So external keyboards do not work without a modification.

I assume that OpenSpand will not be able to inject keystrokes as well.

Possible solution: Add 5 diodes at the output of the 74HC257 and some pull up resistors to those lines.
Minstrel 2 might be similar to that.

I implemented that at my minstrel but was not able to test an external keyboard yet.

Greetings from Mustermann