how did zx spectryum programmers make those big character graphics in games?

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Crayon21
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how did zx spectryum programmers make those big character graphics in games?

Post by Crayon21 »

Jet pac, Jet Set willy, Exolon. How did programmers manage to get the character so big? I can only manage small versions
if not BASIC, then how, outside of assembly?
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Re: how did zx spectryum programmers make those big character graphics in games?

Post by dr beep »

Outside assembly?

Define UDGs and use those to print, like SMURFS
https://www.spectrumcomputing.co.uk/ent ... m/Schlumpf
dr beep
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Re: how did zx spectryum programmers make those big character graphics in games?

Post by dr beep »

dr beep wrote: Thu Feb 22, 2024 9:09 pm Outside assembly?

Define UDGs and use those to print, like SMURFS
https://www.spectrumcomputing.co.uk/ent ... m/Schlumpf

or make your own characterset
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Re: how did zx spectryum programmers make those big character graphics in games?

Post by XavSnap »

Xavier ...on the Facebook groupe : "Zx81 France"(fr)
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RS232
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Re: how did zx spectryum programmers make those big character graphics in games?

Post by RS232 »

Break into the listing of the Horizons tape or a 16/48k nagazine tape they use a machine code routine to do it.
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Re: how did zx spectryum programmers make those big character graphics in games?

Post by XavSnap »

In BASIC, you had to print the word on the screen, test each pixel and print a colored space on the screen to get big chars.
The second way is to test a binary from an UDG.
In BASIC, this routine is very slow.

ASM routine:http://www.hebdogiciel.free.fr/hd-roms/ ... settes.zip
On ZX81 : http://abandonlistings.free.fr/ordi5/hd ... etters.zip
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Re: how did zx spectryum programmers make those big character graphics in games?

Post by 1024MAK »

There is a faster way in BASIC, but it uses it's own "font" stored as DATA statements within the program. At seven or eight bytes per character, this does mean a lot of data statements to enter if you want the full character set... It also uses a lot of RAM in comparison.

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