MiniMorse For ZX80

Any discussions related to the creation of new hardware or software for the ZX80 or ZX81
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TheSnial
Posts: 8
Joined: Sun Apr 14, 2019 10:42 pm

MiniMorse For ZX80

Post by TheSnial »

It's possible to write a variant of MiniMorse for the 1K ZX80. We need to do this in two parts. Strings can't be indexed on a ZX80; we can't type all the printable characters (can't type inverse characters); and some characters are remapped if you type them (e.g. PRINT CHR$(18), CODE("-") displays '-' then 220. You can find the character set near the end of the user manual at this URL: https://cdn.hackaday.io/files/170707730 ... Manual.pdf.

So, instead we put the conversions in a REM statement and PEEK them. Programs start at 16424 and the first character of a REM statement is at 16427. So, the first stage is to enter all the Morse codes we can't easily enter (i.e. the letters).

Image
RUN the program and type the values on the second row:

Code: Select all

A.B. C. D E F. G. H. I J. K. L. M.N O. P. Q. R. S T U. V. W  X. Y. Z
6 17 21 9 2 20 11 16 4 30 13 18 7 5 15 22 27 10 8 3 12 24 14 25 29 19
After it has run, check the REM statement matches the first line of the final program. When it does, delete lines 30 to 70 and complete the rest of the program as shown below:

Image

MiniMorse for the ZX80 works slightly differently, because you have to press <Newline> after typing in the letter or Morse pattern you want to convert: the ZX80 doesn't support INKEY$. The easiest way to escape the program is by typing in 0 and then pressing <Space> immediately after pressing <Newline>.

This version of MiniMorse for the ZX80 is a mere 325 bytes long, shorter than the ZX81 version!
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Paul
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Joined: Thu May 27, 2010 8:15 am
Location: Germanys west end

Re: MiniMorse For ZX80

Post by Paul »

Thanks for this!
I love it when new programs for my loved ZX80 are created.
In theory, there is no difference between theory and practice. But, in practice, there is.
TheSnial
Posts: 8
Joined: Sun Apr 14, 2019 10:42 pm

Re: MiniMorse For ZX80

Post by TheSnial »

You're welcome!

My first computer was a ZX80, for Christmas 1980 (when I was 12). 1K. Strangely, with an inverted display! Second hand!

I sold it for £40 in mid 1981 as part of the trade-off for getting a ZX81.

There's an austere beauty about the ZX80 & it's surprising what you can get it to do - programs are much more compact!

Amazingly, a Uni colleague gave me one in 1997! Can you believe it?! He'd bought two for almost nothing from a Radio Rally. I've powered it up every few years.

The accessibility of the ZX81's PCB really lead me to getting into embedded computing. I was perpetually intrigued as to how the collection of logic chips, CPU, ROM and RAM on the ZX80's PCB conspired to implement a full computer.
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