TS1500 and ZXPand

Discussions about Sinclair ZX80 and ZX81 Hardware
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

TS1500 and ZXPand

Post by Lardo Boffin »

I have just received an edge expander from pokemon via Sell My Retro and look at this! :shock: :o

A nice hires game loaded from my ‘spand:-

482C656A-B1D6-419C-AFC0-D0ACBF26C68E.jpeg
(761.29 KiB) Downloaded 363 times

A marvelous edge connector:-

0B81736A-2543-4546-B528-1C781AFF7894.jpeg
(508.72 KiB) Downloaded 363 times

The only issue i have found using my spand with the TS1500 is that if I reset it I have to cycle the power - it always comes up with an error. It doesn’t do this on my other zeddies. A small price to pay. :D

Thanks to Bean for suggesting the printer connection idea.
Bean wrote: Thu Nov 02, 2017 2:30 pm I use a ZXpand on my TS1500 by plugging the TS2040 printer in first. Works fine.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
sirmorris
Posts: 2811
Joined: Thu May 08, 2008 5:45 pm

Re: TS1500 and ZXPand

Post by sirmorris »

Nice job!

However I feel I should warn about the fact that both the ZXpand and the TS1500 can simultaneously try to drive the bus when accessing RAM above 32k.

When the '1500 has external memory pulling on its RAMCS line on the edge connector it remaps the internal 16k to sit at 32k. If you start POKEing around nothing bad should come of it because both memory will be reading the bus, but PEEKing will have both ram chips outputting at the same time. If RAM has previously been initialised to some value in that range then both chips will be driving the same value which may be OK. If the RAM is uninitialised then they may drive different values - I don't know what would happen in this case.
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Re: TS1500 and ZXPand

Post by Lardo Boffin »

sirmorris wrote: Tue Nov 21, 2017 3:26 pm Nice job!

However I feel I should warn about the fact that both the ZXpand and the TS1500 can simultaneously try to drive the bus when accessing RAM above 32k.

When the '1500 has external memory pulling on its RAMCS line on the edge connector it remaps the internal 16k to sit at 32k. If you start POKEing around nothing bad should come of it because both memory will be reading the bus, but PEEKing will have both ram chips outputting at the same time. If RAM has previously been initialised to some value in that range then both chips will be driving the same value which may be OK. If the RAM is uninitialised then they may drive different values - I don't know what would happen in this case.
Heard loud and clear! At my risk in case it blows up.

To be honest I will only be using it to play the games I find too irritating on the normal zeddy keyboard.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
User avatar
gammaray
Posts: 590
Joined: Sun Apr 17, 2016 2:44 am
Location: Texas

Re: TS1500 and ZXPand

Post by gammaray »

The 1500 has a routine to switch to channel 2 or 3 by pressing that number in the first few seconds after power on. That may have something to do with reset problems.

Now you HAVE to add a KDLX48 by Pokemon for the Spectrum it fits the 1500.

Charles
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Re: TS1500 and ZXPand

Post by Lardo Boffin »

gammaray wrote: Tue Nov 21, 2017 6:01 pm The 1500 has a routine to switch to channel 2 or 3 by pressing that number in the first few seconds after power on. That may have something to do with reset problems.

Now you HAVE to add a KDLX48 by Pokemon for the Spectrum it fits the 1500.

Charles
Funnily enough i was looking at those and wondering....
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
User avatar
gammaray
Posts: 590
Joined: Sun Apr 17, 2016 2:44 am
Location: Texas

Re: TS1500 and ZXPand

Post by gammaray »

I have converted two with the KDLX. Cuz the Chiclet keyboard is better but not as good as the KDLX!
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
sirmorris
Posts: 2811
Joined: Thu May 08, 2008 5:45 pm

Re: TS1500 and ZXPand

Post by sirmorris »

They are a very worthwhile upgrade. It has to be said.
User avatar
Paul
Posts: 1511
Joined: Thu May 27, 2010 8:15 am
Location: Germanys west end

Re: TS1500 and ZXPand

Post by Paul »

I seem to remember that there was a TS1500 GAL for the old ZXPand.
Is that correct?
In theory, there is no difference between theory and practice. But, in practice, there is.
sirmorris
Posts: 2811
Joined: Thu May 08, 2008 5:45 pm

Re: TS1500 and ZXPand

Post by sirmorris »

Correct.

It is possible to re-program the CPLD on ZXpand+ in-system, in a similar way to the device firmware. So having a 1500 configuration is just a matter of testing. It can give RAM from 16-64k where the 1500's internal memory sits at 32-48k. If I understand It Correctly that is.
User avatar
Paul
Posts: 1511
Joined: Thu May 27, 2010 8:15 am
Location: Germanys west end

Re: TS1500 and ZXPand

Post by Paul »

For TS1500 config "m=l" should apply RAM in 8-32K area. And RAMCS always high.
config "m=h" should apply RAM in 16-32 Area. And RAMCS always high.
This way you can switch RAM at 8k on and off (ROM there) and have RAM IN 16-32K area.
The TS1500 then always adds RAM at 32-48k.

This should give maximum compatibility.
Any better ideas?

What did the TS1500 GAL? Anything different?

One should be aware that this ZXPand is TS1500 mode running.
Or can you even add a config command to swap between both modes for ZXPand +?
Auto detection won't be easy...
In theory, there is no difference between theory and practice. But, in practice, there is.
Post Reply