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Looking forward to summer later in the year.
Baggey wrote: ↑Tue Aug 08, 2023 11:13 am
My Display isn't working correctly and the aliens aren't dropping to the floor? This could be because im not triggering interrupts or because the display timing isn't correct they may be linked to this.
The dropping on the screen is not a part of displaying the screen.
If the aliens must drop it is part of the game.
You might have a wrong emulated opcode.
As for perfect display: you need to read Wilf Rigters page about the screen.
Timing of the code is relevant (each opcode must be calculated) and then the display of the data pointed by I and R
in highmemory is the only display part.
Timing is crucial if you want to run my 1K hires games.
Thanks for the Links! So i try and throw a ZX80 Rom in and it dosent work!?
Just realized VARS is different and there appears to be no CDFLAG. So does the ZX80 run in FAST all the time ie 65000 instead of the 16000 that the ZX81 does?
Currently searching for descent links on the ZX80
Ive read the Hi-Res stuff but i cant find anywhere were the screen DFILE starts and what layout it's in?
Manic Miner loads and i can see the Screen in my live Memory Mapper which helps a lot of the time i can zoom in and get the DFILE address that way but is it just rastered? I think not. Im confused but im understanding that the I register points to the CHARS but we should only read 8 pixels but im not glueing how it's laid out. is it line by line or character by character etc..
Any help much appreciated
Kind Regards Baggey
Running a PC that just Aint fast enough!? i7 Quad core 16GB ram 1TB SSD. DID Technology stop! Or have we been assimulated!
ZX Spectrum 48k, C64, ORIC Atmos 48K, Enterprise 128K, The SID chip. Im Misunderstood!
The ZX80 does not have a ‘SLOW’ mode. So yes, it’s effectively running in ‘FAST’ mode. This is because it does not a NMI generator. Hence why you will find descriptions about the display flickering every time you press NEW LINE…
The 4K byte ROM also knows nothing about the extra video functionality from the ZX81 ULA.
The link in my first post in this topic does provide some ZX80 information. Please read through the linked web page.
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.