dk'tronics 4K Graphics ROM
dk'tronics 4K Graphics ROM
Got the above chip in my ZX81. Not sure if it's a common thing or not but it was installed by a mate whose ZX81 I bought when he moved on to being a Spectrum owner.
The manual indicates that there are 8 separate graphics character sets that can be used (including the standard Sinclair set) and also the ability to create two sets of user defined graphics.
The manual indicates that there are 8 separate graphics character sets that can be used (including the standard Sinclair set) and also the ability to create two sets of user defined graphics.
Re: dk'tronics 4K Graphics ROM
Yep, that's the one, based on the manual I have.
Re: dk'tronics 4K Graphics ROM
Are there complete schematics available? I saw some through the link but not sure if that is enough to reproduce.
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
Re: dk'tronics 4K Graphics ROM
It's a basic ROM expansion, base on the $2000 offset.Are there complete schematics available?
A single IR redirection to the $2000 memory bloc.
Just get a ROM expansion card set at $2000 to $3FFF (low memory)
Xavier ...on the Facebook groupe : "Zx81 France"(fr)
Re: dk'tronics 4K Graphics ROM
Internationals pictures...
Xavier ...on the Facebook groupe : "Zx81 France"(fr)
- 1024MAK
- Posts: 5131
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: dk'tronics 4K Graphics ROM
I have reverse engineered a schematic, but it only exists as a hand drawn draft on paper at the moment. When I have time, I will redraw it in a CAD program and then post it in this thread. You will have to wait for a while though, as I am rather busy at the moment.gammaray wrote:Are there complete schematics available? I saw some through the link but not sure if that is enough to reproduce.
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.
Re: dk'tronics 4K Graphics ROM
Is it done yet?
- 1024MAK
- Posts: 5131
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: dk'tronics 4K Graphics ROM
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.
Re: dk'tronics 4K Graphics ROM
This ????but it only exists as a hand drawn draft on paper at the moment.
Xavier ...on the Facebook groupe : "Zx81 France"(fr)