Sinclair ZX80 / ZX81 / Z88 Forums

Finally found time to finish this today but its not quite there and working yet.

I have uploaded the firmware from the links earlier in this post and when connected to power the red light is on and the blue flashes intermittently but regularly.

I have connected it to the zeddy and when I do LOAD “” it appears to be loading for a few seconds but then I either get:

1) Grey screen and reset back to K
2) Grey screen and lock up
3) Some text on the screen - looks like “ZX IO T”


If I get 3) then I can list the program, to some extent:

I’m using an early issue one, bugged ROM, no back porch ULA. As it is not comp modded (and does not have a keyboard yet) I am using a Chroma 81 and external keyboard.

I assume it needs 16K of RAM so have tried:

1) The RAM in the Chroma 81
2) The RAM in a Memotech 16K RAM pack
3) A ZXPand+

This is the Wifi module:

And some fitting:

And loading:

Any advice appreciated!

Thanks!

If I remember correctly I could not get it to work with ZXpand.

I use it with Sinclair 16k RAM pack.

I think you got very far, as you actually loaded some program.

I think you need to ask for help in the German forum, as they know this device more than everyone else.

https://forum.tlienhard.com/phpBB3/viewtopic.php?t=3360

Thanks Martin.

To be sure the zeddy and RAM pack are both working I disconnected the Wespi and loaded a 16K game ok, so I guess they are fine.

I will reconnect and give it another go then join the forum if I don’t get any further.

I made a wespi and mrtinb is right that it doesnt work with zxpand unless you turn off the zxpand rom.

It looks like the wespi loads some fastloader then does another load to get the menu programme? zxpand will load from tape if you load"" but from the sd if you load with a program name. Maybe wespi is loading with a name so zxpand tries to load it but its not on the card so it fails?

If you disable the zxpand rom it all works fine. config "x" before you load"" it works fine for me. I wonder if something can be changed in zxpand to make them work together? I think it's not so important because zxpand loads quicker anyway. Or maybe wespi so it does a second load"" with no name?

Thanks.

I have also tried this with a standard Memotech 16K RAM pack and get the same results.

When I try it I get about 6 seconds of loading lines on the screen, then it goes grey and resets to the K.

The wespi continues to flash blue for a few seconds after the load fails.

What is the normal flashing pattern for these? When switched on mine has a solid red LED and then has a consisten blue flashing LED.

I wonder if it is worth trying to reflash the wespi?

I had 2 problems when getting mine to work:

• I had trouble flashing the ESP32, as the instructions were for a Windows-only program. I finally found how to do it on the command line on a Mac. Beware here that the ESP32 comes in different versions, and not all versions have been successful with the firmware.
• After the flashing I could still not get it to work. I finally found that one of my resistors had a wrong value. So finally it worked, when it was replaced.

It has been a little stone filled road for more of us, so the German forum is the best place to find help, as we have very bright electrical engineers there that designed the device.

Lardo Boffin wrote: ↑Thu Feb 17, 2022 8:56 pm I’m using an early issue one, bugged ROM <SNIP>

With or without the ‘dead cockroach’ ‘fixer’ board? The dead cockroach board could well mess things up.

It’s very possible that the software is expecting one of the two later ROMs, especially if it copes ROM code or calls/jumps to any of the ROM code routines.

Although I have bought the bits for this project, lack of hobby time means I’ve not progressed any further

Mark