Sinclair ZX80 / ZX81 / Z88 Forums

The ZXpand and the Minstrel situation

The ZXpand

These were designed by Charlie Robson (sirmorris on forums). The original design was for ZX81 and TS1000 computers. Later he produced a version that worked with a ZX80. He has already manufactured hundreds of ZXpands. More recently a model that includes the sound chip was designed, manufactured and sold as the ZXpand+.

If you want a ZXpand+, when available, they are normally sold on Sell My Retro.
This was the last (most recent) listing for ZXpand+ systems...

They sell out faster than hot cakes. So I suggest you register on the site and make use of the ‘notify when back in stock’ facility.

The Minstrel ZXpand

These are based on the ZXpand, but are designed only for use with the Minstrel. They are produced by Dave Curran. Please read his blog posts about the Minstrel ZXpand and his range of Minstrel computers at these links:

The Minstrel ZXpand
Minstrel Building Hints and Tips
Minstrel Updates

Due to the COVID19 Corona virus outbreak, he is not happy to operate his Tindie Store - See his message here and his blog post here. He may or may not reopen it next year. In the meantime some of his products are available from TFW8b.
If you want a Minstrel ZXpand on its own before then, then I suggest you contact Dave direct and ask him.

EDIT: 2020-11-09 updated and linked to Dave’s latest blog post.

Mark

As far as I know Mark no special version of the ZXpand (I have them all)was produced for the ZX80, only a change of the ZX80's ROM , all that is required then is a suitable ribbon extender cable between the two so as to allow access to the rear sockets, the fitting of 2 jumper pins on the ZXpand and when "jumped" is now ZX80 ready.

I mention this only so that anyone interested enough doesn't waste time looking for a ZX80 only device.

The ZXpand+ has to be flashed with different firmware for ZX80 use and is reversible back to ZX81 use.

All early ZXpands up to final V5 work with both computers.


A bit of trivia, like the ZX81 motherboards, there isn't a version 2 of the ZXpand only 1 and 3.Like the 81 it goes straight to 3 then (in the ZXpands case) 5 so no four either.

LATE EDIT

Actually I got my sums (spands?) wrong. Original spands are issues 1 and 3.
The issue 5 spand is the start of the spand + series .

Personally I blame the second bottle of scotch.

Moggy wrote: ↑Sun Nov 08, 2020 4:49 pmI have them all

No wonder they’re hard to get hold of. I bet you have them stockpiled floor to ceiling

[Only joking ]

Yes, the ZXpand itself is the same, but what I was trying to say, was that at one time a package of a ZXpand, including the relevant ROM for use with a ZX80 and the ribbon extender cable we’re being sold for use with ZX80 computers. Although I think the ribbon extender cable was also available separately.

Moggy wrote: ↑Sun Nov 08, 2020 4:49 pmA bit of trivia, like the ZX81 motherboards, there isn't a version 2 of the ZXpand. Like the 81 it goes straight to 3 then (in the ZXpands case) 5 so no four either.

I learn something new every day. Did not know this. I hadn’t even thought to check the ZXpands that I have.

Mark

1024MAK wrote: ↑Sun Nov 08, 2020 7:35 pm

Moggy wrote: ↑Sun Nov 08, 2020 4:49 pmI have them all

No wonder they’re hard to get hold of. I bet you have them stockpiled floor to ceiling

[Only joking ]

Yes, the ZXpand itself is the same, but what I was trying to say, was that at one time a package of a ZXpand, including the relevant ROM for use with a ZX80 and the ribbon extender cable we’re being sold for use with ZX80 computers. Although I think the ribbon extender cable was also available separately.

Moggy wrote: ↑Sun Nov 08, 2020 4:49 pmA bit of trivia, like the ZX81 motherboards, there isn't a version 2 of the ZXpand. Like the 81 it goes straight to 3 then (in the ZXpands case) 5 so no four either.

I learn something new every day. Did not know this. I hadn’t even thought to check the ZXpands that I have.

Mark

Had to do some re-checking myself Mark.

In my whisky addled brain I miscounted and have altered my previous post to reflect this.

So Issue 1 and 3 original spand.
Issue 5 Prototype purple board spand+( God I miss those ultra bright blue and pink LEDs), then black shiny issue 5 spand+ and now issue 5.1 black matt finish spand+.

Some other points to dwell on.

The issue three had a slight hardware glitch insofar as if used with the AY board attached then a wire had to be soldered between two pins on the board to receive a clock signal, otherwise silence would ensue.

The 1 and 3 spands AY board (to sound at the correct pitch) should only be fitted with the Yamaha variant of the AY chip ( which has a dual clock setting) and is set in the spand firmware to the higher setting, The Spand+ will use either Yamaha's chip or the original GI chip as the spand+ AY is firmware set at the lower setting of the GI chip.
Personally I prefer the GI chip as it has a more gritty quality to it (well to my ears it does)

If using the turbo sound board only two chips of identical type can be fitted. If a Yamaha chip is fitted alongside a GI chip, only the Yamaha will sound.

The v5 spand+ has 2 regulators side by side fitted and if used with the original Sinclair power supply they get mightily hot, to a point in my opinion that would shorten their lifespan especially if enclosed in a case. The v5.1 has the same two regulators now fitted on opposite sides of the board but I would say the same thing applies re power supplies.

Using a good regulated power supply fixed at 7.5V allows them to run at a more reasonable temperature and should ensure longer life.

1024MAK wrote: ↑Sun Nov 08, 2020 7:35 pm Yes, the ZXpand itself is the same, but what I was trying to say, was that at one time a package of a ZXpand, including the relevant ROM for use with a ZX80 and the ribbon extender cable we’re being sold for use with ZX80 computers. Although I think the ribbon extender cable was also available separately.

I think the reason is, that the ZX80 has not the /ROMCS on the outer connector to switch off internal ROM from ZXpand.

PokeMon wrote: ↑Tue Nov 10, 2020 2:46 pm

1024MAK wrote: ↑Sun Nov 08, 2020 7:35 pm Yes, the ZXpand itself is the same, but what I was trying to say, was that at one time a package of a ZXpand, including the relevant ROM for use with a ZX80 and the ribbon extender cable we’re being sold for use with ZX80 computers. Although I think the ribbon extender cable was also available separately.

I think the reason is, that the ZX80 has not the /ROMCS on the outer connector to switch off internal ROM from ZXpand.

Just to let you know Charlie helped me to install the ZXpand+ on my ZX80 with great success.

viewtopic.php?f=10&t=3751

Instead of using a ribbon expander I just extended the composite out instead