UDG 4 ZXpand / ZXblast

ZX80 / ZX81 hardware and software offered for sale or swapping
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Andy Rea
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Location: notts UK

Re: UDG 4 ZXpand / ZXblast

Post by Andy Rea » Fri Aug 25, 2017 2:22 pm

i have started a new discussion about using the UDG board

viewtopic.php?f=7&t=2533

regards Andy
6 x ZX81, 1 x TS1500 , 1 x +3e, 1 x timex 2040 printer, 1 x timex 2020 cassette deck, siclair printer and some spectrum

Moggy
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Re: UDG 4 ZXpand / ZXblast

Post by Moggy » Fri Aug 25, 2017 3:00 pm

siggi wrote:
Fri Aug 25, 2017 12:57 pm
Moggy wrote:
Fri Aug 25, 2017 11:35 am
QUOTE.

"Changing the i register takes only 5 bytes so can be poked into a line 1 rem statement so charsets can be used easily from basic also."

This is the bit that leaves me stumped. :oops:
I have created some UDG's but don't know how to display them using basic any chance of a simple example, say a line of "X"'s being turned into a UDG of my choice?
The 5 bytes in M/C are necessary to change the I register to point to another UDG-character set in RAM. You could use standard POKE command to store the UDG pattern there by BASIC.
I have done that also in my UDG game:
viewtopic.php?f=6&t=526&p=4987&hilit=Interc+u#p4987

Regards
Siggi
Thanks Siggi much appreciated. :D

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1024MAK
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Location: Looking forward to summer in Somerset, UK...

Re: UDG 4 ZXpand / ZXblast

Post by 1024MAK » Sat Aug 26, 2017 5:35 pm

Mine arrived today 8-)
IMG_5200.JPG
UDG 4 ZXpand and some 3.5mm mono jack plugs and sockets
(255.52 KiB) Downloaded 538 times
(Along with a few other bits from eBay)

Thank you Andy :D

Mark

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siggi
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Re: UDG 4 ZXpand / ZXblast and any other ZX81

Post by siggi » Wed Aug 30, 2017 4:28 pm

Some years ago I also thought about an extension to have UDG on any Zeddy: a 8KByte static ram on a small board inside the ZX81 (within the ROM socket, carrying the RAM and ROM). Nowadays I would use single gates instead of a GAL:

http://forum.tlienhard.com/phpBB3/viewt ... 3857#p3857

Maybe that would also be useful nowadays ...

Siggi
My ZX81 web-server: online since 2007
http://zx81-siggi.endoftheinternet.org/index.html

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Andy Rea
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Location: notts UK

Re: UDG 4 ZXpand / ZXblast

Post by Andy Rea » Wed Aug 30, 2017 4:31 pm

ah yes, the internal mod is a little easier.

regards Andy
6 x ZX81, 1 x TS1500 , 1 x +3e, 1 x timex 2040 printer, 1 x timex 2020 cassette deck, siclair printer and some spectrum

Moggy
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Re: UDG 4 ZXpand / ZXblast

Post by Moggy » Wed Aug 30, 2017 5:00 pm

Andy Rea wrote:
Wed Aug 30, 2017 4:31 pm
ah yes, the internal mod is a little easier.

regards Andy
But the green board looks nicer. ;) :lol:

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siggi
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Re: UDG 4 ZXpand / ZXblast

Post by siggi » Wed Aug 30, 2017 6:20 pm

My 2 boards arrived this day :mrgreen:
Thanks a lot
Siggi
My ZX81 web-server: online since 2007
http://zx81-siggi.endoftheinternet.org/index.html

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hsimpson
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Location: Poland

Re: UDG 4 ZXpand / ZXblast

Post by hsimpson » Wed Aug 30, 2017 10:23 pm

My UDG board arrived this day, too :D.
Thank You very much.

nollkolltroll
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Re: UDG 4 ZXpand / ZXblast

Post by nollkolltroll » Thu Aug 31, 2017 8:26 am

Board received Monday, and I had time to try it out. All works as expected with the ZXpand :D
Will try it with a classic memory expander some time...
/Adam

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Andy Rea
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Re: UDG 4 ZXpand / ZXblast

Post by Andy Rea » Thu Aug 31, 2017 8:43 am

Hi Adam, goid to hear it arrived safely. By classic memory expander you mean the Sinclair 16k ram pack?

Regards Andy
6 x ZX81, 1 x TS1500 , 1 x +3e, 1 x timex 2040 printer, 1 x timex 2020 cassette deck, siclair printer and some spectrum

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