128k improvements

For experts to discuss very technical stuff and newbies to ask why the Spectrum they bought off ebay doesn't work.
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MrPixel
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128k improvements

Post by MrPixel »

Outside of music (of which the 128k rules) what other improvements did the 128k bring
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PeterJ
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Re: 128k improvements

Post by PeterJ »

Obviously more memory was the biggest thing, some improvements to the BASIC, and a better keyboard (which was introduced with the Spectrum+).
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1024MAK
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Re: 128k improvements

Post by 1024MAK »

Err, the "serial" and "aux" ports (on the Spanish version, there was a keypad that plugged into the "aux" port).

As well as the extra RAM, the ability to have two banks of screen memory that could be chosen by a assembly program, so you could flip between them.

Mark
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Ast A. Moore
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Re: 128k improvements

Post by Ast A. Moore »

MIDI, RS232 port, RGB video output, composite video output, eliminated “dot crawl.”
Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
MrPixel
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Re: 128k improvements

Post by MrPixel »

Ast A. Moore wrote: Thu Jun 28, 2018 8:37 pm MIDI, RS232 port, RGB video output, composite video output, eliminated “dot crawl.”
dot crawl?
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PeterJ
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Re: 128k improvements

Post by PeterJ »

MrPixel
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Re: 128k improvements

Post by MrPixel »

thanks. yeah, that helps
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Ast A. Moore
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Re: 128k improvements

Post by Ast A. Moore »

Even more obvious in this video:
[media]https://www.youtube.com/watch?v=5Dk136-Q7cM[/media]
Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
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1024MAK
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Re: 128k improvements

Post by 1024MAK »

MrPixel wrote: Thu Jun 28, 2018 9:25 pm
Ast A. Moore wrote: Thu Jun 28, 2018 8:37 pm MIDI, RS232 port, RGB video output, composite video output, eliminated “dot crawl.”
dot crawl?
Interference on a video picture due to the colour encoder circuitry using a different master oscillator to the rest of the video system and due to the limitations of mixing colour information in with the monochrome video signal.

Because the colour information is added to the monochrome video signal, at the display (TV), the video circuitry in the display system is unable to distinguish between the two signals, and hence incorrect colour and detail is shown. Because the two different oscillators in the computer are independent, the phase relationship is constantly changing. Hence the patterns on the display are also constantly changing. So it got coined "dot crawl" as it appears that many dots are crawling across the picture...

Mark
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“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :dance
Looking forward to summer later in the year.
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1024MAK
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Re: 128k improvements

Post by 1024MAK »

This video
[media]https://youtu.be/_tAtCmvLCn0[/media]
https://youtu.be/_tAtCmvLCn0
Shows the difference in quality between RGB (from the SPECTRA interface), composite video and the RF/UHF signal.

Mark
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :dance
Looking forward to summer later in the year.
MrPixel
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Re: 128k improvements

Post by MrPixel »

thank you all for the replies. it has helped a lot
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