Sinclair ZX80 / ZX81 / Z88 Forums

Im at the Vintage Computer Festival Mid West demo-ing the ZXPand+ and ZXmore board. All has been working all day great.

I decided to see if Siggi's (Wiznet) - IRC chat board would work with my modified ZXmore for ZXPand+. Nothing happened so I unplugged all. When I bring up the ZXPand+ with instance 1-7 switched on the ZXmore all is good. However, I can't get anything on ZXmore instance 0 when the ZXmore is alone again (with A3 jumper back in) J12. white screen (no inverse K) on instance 0 switched.

Karl - Can I reload firmware or other ideas?

Thanks - Tim

ZXmaster firmware is not coming on. If I switch to instances 1-7, I cant double shift for loading programs. I tried copying zxmore19.p from my zxpand+ plugged into ZXmore on switched instance 1, but I wasnt sure what to enter exactly. Nothing is working so any help would be appreciated.

Thank you - Tim

Karl,

Please PM me to ship me (3) to be safe with spares - CPLDs modified with the latest build like you sent me before that work with the ZXPand+. For PayPal or other charging as not to waste more time.

Thank you - Tim

Tim

It may be worthwhile checking that the link/jumper shunt and it's connections are okay.

Mark

All is good with the A3 shunt. Nothing happens now at Instance switch 0 (blank white screen). Other switched instances get the Inverse K (with/with out zxpand+) but no menus come up when double shifting. Acts like regular zx81s. I think it's best to just get some new CPLDs for ZXPand+ since I can't program them myself.

Thanks

Tim

I would propose to check the flash rom and maybe send you a new flash rom as well.
It is unlikely, that the CPLD has a problem. Is the led off when you switch to instance 0 ?
Any wires removed which fixed the board to instance 1 before ?
I think if accidently started it should light up in a colour.
What pullup did you use on "AX" (which can be A3-A7 accordingly to the jumper J12) ?

Karl,

Hmm Flashrom. ok. Where is that at? I sent you a paypal for euros as described in my PM so whatever I can get for that to help and have spares possibly - please send me.

The LED is off on Instance 0. If the ZXPand+ is plugged in (A3 not jumpered with 10K resistance A3), I get that scrambled character code screen (typing can show movement underneath). If no ZXPand+ with A3 jumpered, I get a white screen.
On instances 1-7? (LEDs turn on appropriately) with or without ZXPand+ I get the inverse K but there is no double-shift capability (i.e. shift-shift 0, shift-shift L).
There are no wires removed. All I did was plug in the Ethernet Wiznet card with the ZXPand+ behind it and the screen went blank. I see in your youtube video you use the Ethernet Wiznet cart (not with ZXPand+ though) so I thought it would be ok. I was demo-ing the ZXmore and ZXPand+ at the computer show this weekend when I had to leave earlier than expected. But don't worry, I suspect you will get plenty of orders for ZXmore and ZXblast too.

As you know I have been using (2) 4.7k resisters in series for 10K resistance on A3 to +5vdc I believe. See the past pics I sent showing this.

Thank you,
Tim

FlashROM = ROM. It's one of the two large DIL chips at the top left of the board.

Mark

I finally got a chance to see what happened to my ZXmore. It was the programmed flash rom chip not the CPLD. All comes on correctly now. Thanks again Karl!

Tim

I trust that it is now working okay?

Mark