Sinclair ZX80 / ZX81 / Z88 Forums

I downloaded V1.8 this morning, which is the version I am using.

Just a thought. Have you removed the firmware update from the SD, so it doesn't try to update at every boot?

Oh yes I removed it as soon as the firmware updated successfully.

Does it matter that my Zeddy is issue 1 with the unpatched ROM, and my ZXPand is several years old?

Your Zeddy ROM should make no difference, as the ROM of the ZXpand is taking over.

Whether is ZXpand Commander only works on ZXpand+ or also the regular ZXpand, I don't know. My understanding has been, that they are quite similar hardware-wise, and ZXpand + the AY-board was squeezed into one: the ZXpand+.

angus wrote: ↑Wed Apr 07, 2021 3:38 pm Does it matter that my Zeddy is issue 1 with the unpatched ROM, and my ZXPand is several years old?

This is the reason for the problem, the first version of the ROM does not have the calls at the end of the ROM, used by ZXpand Commander. So, you must update your ROM.

Or try with an older version, to see if it works

I've tried Commander 1.1 I think, and 1.8 and none work.

I do have an Issue 2 Zeddy and could try with that. Shame as I really enjoy using the old one and I am going to keep that motherboard with the genuine Zilog Z80, March 1981 ULA and klutzed ROM as it left the factory. I've switched to my older Zeddy for it's 40th birthday

Are you sure you are talking about the same thing?

Are we talking about the ROM in the ZX81, or the ROM on the ZXpand?

I'm talking about ZXpand ROM, Commander makes calls to entry vectors that aren't present in first ZXpand ROM release.

angus wrote: ↑Wed Apr 07, 2021 5:05 pm I do have an Issue 2 Zeddy.

Really!?


What kmurta is referring to is the EPROM issue number on the spand which should be at least 6.6 if memory serves as v5.1 may not have the entry vectors he refers to. If that is the case you may have to re-flash the EPROM with v6.6 and if not able to do yourself I'm sure I can work a replacement out should this be the cause.


I have all versions of the spand (no issue 2 there either) and never had trouble after updates with commander I will have play around with mine tonight and see what I can come up with as I still have my old v5.1 EPROM and if that reproduces your fault then that must be the answer.

One other thing to consider is I have had problems with file reading and that type of thing and have found that on at least two of my spands the card needs a hefty sharp knock when pushing it into the slot before it will read anything.

A check reveals that as Kmurta says the older EPROM (V 5.1 in this example ) doesn't possess the necessary hooks usable by commander.
Ignore the inverse screen as that's how I run my zeddies and has nothing to do with your problem.

EPROM updates here...

viewtopic.php?f=13&t=913

Info confirming the above (6 posts down) here...

viewtopic.php?f=6&t=956&hilit=zxpand+co ... m&start=60