Something for Moggy... ( and probably lots of others )
Something for Moggy... ( and probably lots of others )
coming soon....
Anyway back to the story, what do you get if you Cross a Moggy with a DK'Tronics 4K Character Rom and a ZxPand ?
Lets try it shall we... this first
then this
followed by this...
and the result
.... .... ....
what ? how ? you may ask.... well of course i didn't telll you something this little gizmo does the job...
it sits inbetween the zx81 and the ZxPand and allows UDG charcaters to be stored on the ZXpands Ram. This is the first prototype PCB it has 2 bozo's the first was a missing power pin on the chip that i spotted shortly after placing the order... the second... and how in gods name did i forget... was the refresh signal ! anyway the next prototype board is ordered is a little shorter at just 1.5 inches do wont made you ZxPand stickout too far.
QS scamble
galaxians
the controls are very simple.... a 2 way jumper selects between standard UDG i.e 64 characters and there inverts OR chr$128 which gives 128 charcaters or leave the link off altogether to disable UDG
i estimate the sell price to be between 15 to 20 GBP + postage and packing.
Anyway back to the story, what do you get if you Cross a Moggy with a DK'Tronics 4K Character Rom and a ZxPand ?
Lets try it shall we... this first
then this
followed by this...
and the result
.... .... ....
what ? how ? you may ask.... well of course i didn't telll you something this little gizmo does the job...
it sits inbetween the zx81 and the ZxPand and allows UDG charcaters to be stored on the ZXpands Ram. This is the first prototype PCB it has 2 bozo's the first was a missing power pin on the chip that i spotted shortly after placing the order... the second... and how in gods name did i forget... was the refresh signal ! anyway the next prototype board is ordered is a little shorter at just 1.5 inches do wont made you ZxPand stickout too far.
QS scamble
galaxians
the controls are very simple.... a 2 way jumper selects between standard UDG i.e 64 characters and there inverts OR chr$128 which gives 128 charcaters or leave the link off altogether to disable UDG
i estimate the sell price to be between 15 to 20 GBP + postage and packing.
what's that Smell.... smells like fresh flux and solder fumes...
Re: Something for Moggy... ( and probably lots of others )
I thought my lights had gone dim tonight, The mad Midlander is at it again!!!
Nice one Andy.
What with AY,Turbosound, MIDI and now UDG I think this is a fertile time for us zeddy lovers, I might be no sort of games player but I've got to give this little bugger a go!
Nice one Andy.
What with AY,Turbosound, MIDI and now UDG I think this is a fertile time for us zeddy lovers, I might be no sort of games player but I've got to give this little bugger a go!
Re: Something for Moggy... ( and probably lots of others )
oh yeah .. andyyyyy .. oh yeah
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Something for Moggy... ( and probably lots of others )
Nice
Mark
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
-
- Posts: 2173
- Joined: Sat Nov 26, 2016 2:42 am
Re: Something for Moggy... ( and probably lots of others )
Although I have no real need for one I am a magpie when it comes to cool things to plug into my computers - any idea when it will be available to buy?
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
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
-
- Posts: 325
- Joined: Sat Sep 27, 2014 8:02 pm
- Location: Stockholm, Sweden
Re: Something for Moggy... ( and probably lots of others )
But... How?! I thought the expansion bus was on the wrong side of the ula. Please enlighten us!
Good job though, can't wait to buy it!
Good job though, can't wait to buy it!
/Adam
Re: Something for Moggy... ( and probably lots of others )
The ZXpand is the wrong side of the ula.. the chip on this device recreates much of the ULA's circuitry and provides the missing signals.nollkolltroll wrote: ↑Mon Jul 10, 2017 11:00 am But... How?! I thought the expansion bus was on the wrong side of the ula. Please enlighten us!
Good job though, can't wait to buy it!
It has been designed so that it can be completely.disabled so unnecessary plugging and un plugging is eliminated.
Regards Andy
what's that Smell.... smells like fresh flux and solder fumes...
Re: Something for Moggy... ( and probably lots of others )
ooh, will it work with 'normal' ram expansion or only work with zxpand? i was trying to work out a 'programmable' version of wilf righters chr$16 external thingy, and think i've got it, but as theres software that uses the dk tronics system, maybe thats better...OR does it work the same way? changing the I register to point to high byte of character bitmaps!
Re: Something for Moggy... ( and probably lots of others )
I can't guarantee that it will work with other external memory expansions. However.... if your external memory is wrx enabled then in theory it should work.gozzo wrote: ↑Mon Jul 10, 2017 12:27 pm ooh, will it work with 'normal' ram expansion or only work with zxpand? i was trying to work out a 'programmable' version of wilf righters chr$16 external thingy, and think i've got it, but as theres software that uses the dk tronics system, maybe thats better...OR does it work the same way? changing the I register to point to high byte of character bitmaps!
Yes i believe that all the UDG schemes use the I register to point were in memory the character maps are stored.
Regards Andy
what's that Smell.... smells like fresh flux and solder fumes...
Re: Something for Moggy... ( and probably lots of others )
my chr$16 mod doesnt use any of the zx81's ram, as it has its own ram to store the 'bitmaps' so should work with ANY or even no add on ram if i can find the circuit i drew up a few years back i'll post it here, somewhere..never got round to building it but i think 'in theory' it should work...