Sinclair ZX80 / ZX81 / Z88 Forums

The objective of these articles was to try to demystify a little the idea that Forth is a complicated and inaccessible language for most mortals. In fact, for those who allow themselves to venture into their fields, Forth is a fun and very stimulating language for the brain, as it forces us to thin...

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the 2 programs seem to contain only the instructions, no more ...

Moggy wrote: ↑Sun Mar 10, 2024 10:35 am Yes it does.

Example.

." some text "

This is the standard way to print text in Forth.

I would have expected that:

. "txet emos "

You should use Schottky diodes to pull TTL signals to low!

The diodes and the resistor can be soldered directly to the pins of the connector:

https://forum.tlienhard.com/phpBB3/down ... hp?id=8612

(Perfectly viewable on a 22" monitor)

Wilf Rigter has written programs, which use hires display in the upper screen area and text mode in the lower area.
So everything is possible, when using a ZX81, but somebody needs to do it

Hopefully you have plugged in the CPU and ULA the right direction, NOT as shown in the ZX81 manual chapter 25:

https://www.manualslib.com/manual/12017 ... =71#manual

Moggy wrote: ↑Fri Feb 23, 2024 11:53 am I have just the tool for the job!!

No, that tool makes longer slots on the outside and shorter on the inside.
I think, that is a better tool (also for other problems) ...

A much shorter screen saver solution, and also space saving. But be careful: works only on real original Zeddies (not on machines, using a non-compatible ROM like ZxPand, Mefisdos, ZxNU, ZxMore, ZxBlast, ZxDeluxe, ...)

Here it is (incl. 50 Hz screen flicker)

You should replace the black stripes by real slots (for better cooling) ..