My first ZX81

Discussions about Sinclair ZX80 and ZX81 Hardware
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AN7805
Posts: 91
Joined: Fri Oct 16, 2020 4:17 am

My first ZX81

Post by AN7805 »

Arrived today.

Not working, i have repair the keyboard now is working perfectly.

Image

Image

Need only a heatsink for the ULA.
This is a ZX81 Issue 3 the ULA are the last produced, the 2C210E.

Matteo
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AN7805
Posts: 91
Joined: Fri Oct 16, 2020 4:17 am

Re: My first ZX81

Post by AN7805 »

A information,
where is the string for check the 1k memory?

Thanks,

Matt
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PokeMon
Posts: 2264
Joined: Sat Sep 17, 2011 6:48 pm

Re: My first ZX81

Post by PokeMon »

Not sure what you mean.
There is no command to check RAM.
You may use PRINT PEEK 16389 which gives 68 for 1k and 128 for 16k RAM. This is the dirty variant. ;)

Code: Select all

PRINT PEEK 16389*256+PEEK 16388
PRINT PEEK 16389*256+PEEK 16388-16384
This should give RAMTOP address (first line) and RAM installed/available (second line).
Not sure if brackets are needed, dont think so.
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AN7805
Posts: 91
Joined: Fri Oct 16, 2020 4:17 am

Re: My first ZX81

Post by AN7805 »

Thank so much PokeMon.
Yes i said the string's you mean.

Thanks so much,

Matt
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jesperp
Posts: 49
Joined: Fri Jun 10, 2022 11:41 am
Location: Denmark

Re: My first ZX81

Post by jesperp »

PokeMon wrote: Wed Oct 28, 2020 9:59 pm Not sure what you mean.
There is no command to check RAM.
You may use PRINT PEEK 16389 which gives 68 for 1k and 128 for 16k RAM. This is the dirty variant. ;)

Code: Select all

PRINT PEEK 16389*256+PEEK 16388
PRINT PEEK 16389*256+PEEK 16388-16384
This should give RAMTOP address (first line) and RAM installed/available (second line).
Not sure if brackets are needed, dont think so.

This RAMTOP code also goes with Lambda 8300.
Best regards
Jesper Petersen
dr beep
Posts: 2059
Joined: Thu Jun 16, 2011 8:35 am
Location: Boxmeer

Re: My first ZX81

Post by dr beep »

Here are some games to try in 1K.

https://sinclairzxworld.com/viewtopic.p ... res#p45132

Next link will be p2wav so you can load them as sound

viewtopic.php?p=1690#p1690
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