zx spectrum in zx81 case

User avatar
gammaray
Posts: 328
Joined: Sun Apr 17, 2016 1:44 am
Location: Texas

Re: zx spectrum in zx81 case

Post by gammaray » Mon Dec 25, 2017 3:48 pm

Wait a minute now we have to have made and adhesive overlay or dedicated membrane '81 style keyboard for Speccy in the Box...(ZXMax48)

When will we stop innovating? And when will we accept what they give us? :twisted:

Bah humbug! Progress...phooey!
Last edited by gammaray on Mon Dec 25, 2017 7:51 pm, edited 2 times in total.
Finish what you start. Truth is over the mountaintop or six feet under.
4 x TS1000, 2 x TS1500 , 2 x timex 2040 printer, 1/2 x timex 2020 cassette deck, ZXPAND+AY, ZeddyNET, ZXBlast..., unfinished Spectrum...Still no life!

User avatar
Paul
Posts: 901
Joined: Thu May 27, 2010 7:15 am
Location: Germanys west end

Re: zx spectrum in zx81 case

Post by Paul » Mon Dec 25, 2017 4:04 pm

gammaray wrote:
Mon Dec 25, 2017 3:48 pm
Wait a minute now we have to have made and adhesive overlay or dedicated membrane '81 style keyboard for Speccy in the Box...(ZXMax48)

When will we stop innovating? And when will we accept what they give us?
There is Pokémon ZX81 KDLX. We only need a print for Spectrum.
I really hope we never stop innovation.
When I travel to Mars I want a ZX81 Mars edition to take with me.
In theory, there is no difference between theory and practice. But, in practice, there is.

McKlaud
Posts: 34
Joined: Tue Dec 19, 2017 9:02 pm
Location: St Albans, UK

Re: zx spectrum in zx81 case

Post by McKlaud » Mon Dec 25, 2017 5:13 pm

gammaray wrote:
Mon Dec 25, 2017 3:48 pm
Wait a minute now we have to have made and adhesive overlay or dedicated membrane '81 style keyboard for Speccy in the Box...(ZXMax48)
I hope Pokémon or RWAP Software or Tynemouth Software could be very kind to us and make newer version of their membranes. I would definitely buy two of them. Or someone could design and make a rubber overlay with Speccy keys.

BTW I am now waiting for ZX Max 48 Issue 2 PCB with AY chip on it. It is going to be a nearly perfect ZX Spectrum.
Claudius
----------

User avatar
gammaray
Posts: 328
Joined: Sun Apr 17, 2016 1:44 am
Location: Texas

Re: zx spectrum in zx81 case

Post by gammaray » Fri Dec 29, 2017 11:03 pm

Wait. I could come full circle and combine the ZXmax48 with a modified FRANKENZED OR TAZMANIAC I am working on and put in a Spectrum case using the reproduction rubber keyboard and case assembly.

Ok maybe leave it alone and just put a adhesive layer on top of 81 case with KDLX or membrane...
Finish what you start. Truth is over the mountaintop or six feet under.
4 x TS1000, 2 x TS1500 , 2 x timex 2040 printer, 1/2 x timex 2020 cassette deck, ZXPAND+AY, ZeddyNET, ZXBlast..., unfinished Spectrum...Still no life!

McKlaud
Posts: 34
Joined: Tue Dec 19, 2017 9:02 pm
Location: St Albans, UK

Re: zx spectrum in zx81 case

Post by McKlaud » Sat Dec 30, 2017 11:46 am

On the same note, Superfo also designed a small add-on board with a joystick interface and IF2 compatible cartridge slot. As soon as I am back home I will publish some photos of the full set (Issue 1 PCB, the interface and IF2 cartridge) in matching colours. ;)
Claudius
----------

rune
Posts: 149
Joined: Thu Sep 04, 2014 7:35 am

Re: zx spectrum in zx81 case

Post by rune » Mon Jan 01, 2018 1:41 pm

Has anyone built this board yet? I half way through and waiting for the remained or the components to arrive.

McKloud mentioned some problems with the keyboard/diodes and a possible problem with the speaker damaging the transistor. Any other issues encountered?

I have an Altera Max programmer, what software is best/needed to program the CPLD?

Dave

User avatar
gammaray
Posts: 328
Joined: Sun Apr 17, 2016 1:44 am
Location: Texas

Re: zx spectrum in zx81 case

Post by gammaray » Mon Jan 01, 2018 4:10 pm

rune wrote:
Mon Jan 01, 2018 1:41 pm
Has anyone built this board yet? I half way through and waiting for the remained or the components to arrive.

McKloud mentioned some problems with the keyboard/diodes and a possible problem with the speaker damaging the transistor. Any other issues encountered?

I have an Altera Max programmer, what software is best/needed to program the CPLD?

Dave
Is someone willing to program the CPLD for those who can't? Yoda says may the force be with you.
Finish what you start. Truth is over the mountaintop or six feet under.
4 x TS1000, 2 x TS1500 , 2 x timex 2040 printer, 1/2 x timex 2020 cassette deck, ZXPAND+AY, ZeddyNET, ZXBlast..., unfinished Spectrum...Still no life!

rune
Posts: 149
Joined: Thu Sep 04, 2014 7:35 am

Re: zx spectrum in zx81 case

Post by rune » Mon Jan 01, 2018 4:24 pm

If I can program mine, Id be happy to do others.

I've downloaded a program for developing the CPLDs, no idea if it is the correct one or not. Suppose I'll know when I get the board finished.

McKlaud
Posts: 34
Joined: Tue Dec 19, 2017 9:02 pm
Location: St Albans, UK

Re: zx spectrum in zx81 case

Post by McKlaud » Mon Jan 01, 2018 5:38 pm

Hi Guys,

To program Altera Max7000 (EPM7128S) you need software called Altera Quartus II in version 13.0sp1. Any newer Quartus does not support these chips. Anyway, it would be also good if you use Windows 7, because this version does not work very well under Win10 (especially 64-bits one). You can use any cheap Altera USB Blaster available for $2.00, they work fine.

My fully working board below:
Image

Regarding the board itself, there are few recommended modifications. You can see them on photos below:

Additional 33R resistor between the speaker and Q2:
Image

Additional 1k0 resistor in the EAR input circularity (between the EAR input and Q2):
Image

Diodes crossed for the ZX81 keyboard membrane. The other diode is installed on the other side of the PCB:
Image

1A diode and solid link instead of J9 to protect the DC converter from a wrong power supply polarity:
Image
Claudius
----------

rune
Posts: 149
Joined: Thu Sep 04, 2014 7:35 am

Re: zx spectrum in zx81 case

Post by rune » Mon Jan 01, 2018 5:46 pm

Thanks McKloud,

I guess I have a few mods to do tomorrow. Brilliant photos and explanations, hopefully I wont be too far behind getting mine working.

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest