Newbie ZX Spectrum question

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pmra
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Joined: Mar 23, 2021 16:20

Newbie ZX Spectrum question

Postby pmra » Mar 23, 2021 16:42

Hi,

I'm new to FreeBasic and this forum, so first I'd like to greet everyone here and thank you all for your work.
Second I want to say that I am NOT a developper, I only like to learn. I just found FreeBasic and, maybe stupidly, started asking this.

Because of so much pandemic 'free' time, I reopened an old book, containing a ZXSpectrum BASIC listing, something I actually coded and used on a ZX 128K disk 'PC' about 30+ years ago.
So, my question here would be, can that code be somehow converted to FreeBasic? Can I write it and get it converted?
Just to start with the right foot, I found https://www.fbide.freebasic.net/, is this the more appropriate tool to edit/code? Are there others?

Much obliged by any answer, and apologies for the ignorance.
BasicCoder2
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Joined: Jan 01, 2009 7:03
Location: Australia

Re: Newbie ZX Spectrum question

Postby BasicCoder2 » Mar 23, 2021 21:25

There are probably ZX Spectrum emulators out there.
https://dotneteer.github.io/spectnetide/
Translating old code is a pain. Ideally you simply rewrite the program. All programs can be described at a higher level. Just translate up that old code to that higher level and then translate back down to the language you want to use.
MrSwiss
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Re: Newbie ZX Spectrum question

Postby MrSwiss » Mar 23, 2021 21:32

pmra wrote:... is this the more appropriate tool to edit/code? Are there others?

See: FreeBASIC IDEs/Editors listed.
jj2007
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Re: Newbie ZX Spectrum question

Postby jj2007 » Mar 23, 2021 21:40

Hi pmra,

My second BASIC computer was a ZX Spectrum, too, but I don't have listings any more. As BasicCoder2 wrote above, rewriting is probably easier - but in order to judge what to do, we should have a look at your listings. Can you post something, please? I admit I am curious ;-)
pmra
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Joined: Mar 23, 2021 16:20

Re: Newbie ZX Spectrum question

Postby pmra » Mar 24, 2021 15:22

BasicCoder2 wrote:There are probably ZX Spectrum emulators out there.
https://dotneteer.github.io/spectnetide/
Translating old code is a pain. Ideally you simply rewrite the program. All programs can be described at a higher level. Just translate up that old code to that higher level and then translate back down to the language you want to use.

Thanks for answering! I kind of was expecting this. I'll look for a good Freebasic course/tutorial.
pmra
Posts: 7
Joined: Mar 23, 2021 16:20

Re: Newbie ZX Spectrum question

Postby pmra » Mar 24, 2021 15:23

MrSwiss wrote:
pmra wrote:... is this the more appropriate tool to edit/code? Are there others?

See: FreeBASIC IDEs/Editors listed.

Thanks for answering! Will do.
pmra
Posts: 7
Joined: Mar 23, 2021 16:20

Re: Newbie ZX Spectrum question

Postby pmra » Mar 24, 2021 15:47

jj2007 wrote:Hi pmra,

My second BASIC computer was a ZX Spectrum, too, but I don't have listings any more. As BasicCoder2 wrote above, rewriting is probably easier - but in order to judge what to do, we should have a look at your listings. Can you post something, please? I admit I am curious ;-)

Thanks for your interest! Here goes, its about 25 A5 pages of this:
https://imgur.com/a/NwQjx5m
Since I don't have it on digital form, rewriting is definitely the way.
jj2007
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Re: Newbie ZX Spectrum question

Postby jj2007 » Mar 24, 2021 16:02

Agreed! It will be a bit of typing, but it's worth the effort. Note that FreeBasic does not have line numbers - you will use proper names instead. For example:

Code: Select all

If qs="1" then
  Action1
elseif qs="2"
  Action2
elseif qs="3"
  Action3
endif
....
Sub Action1
  ... more code, whatever must be done if q$="1" ...
End Sub
That looks different at first sight, but it's much easier to use, and less confusing than "GOTO 123" ;-)
BasicCoder2
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Location: Australia

Re: Newbie ZX Spectrum question

Postby BasicCoder2 » Mar 24, 2021 19:01

@pmra
Here goes, its about 25 A5 pages of this:
https://imgur.com/a/NwQjx5m
Since I don't have it on digital form, rewriting is definitely the way.

Ouch! How unreadable old code was! I would scan the code and perhaps use an OCR to translate it into text. If I was really keen on translating the old code I think I would work on a program to help with the task.
dodicat
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Location: Scotland

Re: Newbie ZX Spectrum question

Postby dodicat » Mar 24, 2021 19:05

Freebasic can use line numbers if option #lang "qb" or lang "fblite" is used.
Example:

Code: Select all

'rem prime factors
#lang "qb"

1 lowers%=30000
2 uppers%=30500

10 For counts% = lowers% To uppers%
20 number% = counts%
30
40 Print number%;"= ";
50 divisor% = 2
60 While divisor% <= number%
70 Gosub 490
80 divisor% = divisor% + 1
90 Wend       
100 Print
101 Next counts%
102 Print

rem subroutine
490
500 If number%/divisor%-Int(number%/divisor%) = 0 Then
510 c$="x"
520 number% = number% / divisor%
530 If number% = 1 Then c$=""
540 Print divisor%;c$;
550 Goto 490
560 End If
570 If counts%<=uppers% Then Return

580 Sleep

merge or list or eval or plot (and many others I reckon) are not freebasic keywords.
You only need the salient line numbers for the goto's, gosubs, but writing in the others does no harm.
deltarho[1859]
Posts: 3069
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Location: UK

Re: Newbie ZX Spectrum question

Postby deltarho[1859] » Mar 24, 2021 21:13

pmra wrote:I'll look for a good Freebasic course/tutorial.

Go to the following link. Not many people mention this, but it is well-structured and well written.

FreeBASIC Tutorials

The right-hand pane may be blank, click on FreeBasic at the top of the left-hand pane.

There are quite a few example programs - try them.

BTW, the correct spelling is FreeBASIC.
BasicCoder2
Posts: 3738
Joined: Jan 01, 2009 7:03
Location: Australia

Re: Newbie ZX Spectrum question

Postby BasicCoder2 » Mar 24, 2021 23:47

I printed a page of FreeBASIC source code and then scanned it into an image.
I then used an online ocr to convert it back to text. It seemed to work fine.
A nice clean scanned image would be required as when I tried
https://imgur.com/a/NwQjx5m
it didn't convert much of it only a few characters.
deltarho[1859]
Posts: 3069
Joined: Jan 02, 2017 0:34
Location: UK

Re: Newbie ZX Spectrum question

Postby deltarho[1859] » Mar 25, 2021 0:18

It has been hinted at but the way to go is

Code: Select all

Old code -> Pseudo code -> New code

Code: Select all

Old code -> New code

will drive you mad.

Code: Select all

Pseudo code -> New code

needs more than a passing acquaintance of 'New code'. Understand the fundamentals of 'New code' and then consider 'Pseudo code -> New code'.
jj2007
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Re: Newbie ZX Spectrum question

Postby jj2007 » Mar 25, 2021 0:31

Hi pmra,

deltarho[1859] is right: start with pseudocode describing the conditions (if qs="1" Then ...) and actions required. Then look into the help file to see which commands you need for the "actions". Members here will help you with that. You will soon see that FreeBasic is much clearer and easier than Spectrum BASIC ;-)

Code: Select all

If qs="1" then
  Action1  ' ex GOTO 3460
elseif qs="2"
  Action2  ' ex GOTO q11
elseif qs="3"
  Action3  ' ex GOTO 2020
endif
....
Sub Action1
  ... more code, whatever must be done if q$="1" ...
End Sub

Image
deltarho[1859]
Posts: 3069
Joined: Jan 02, 2017 0:34
Location: UK

Re: Newbie ZX Spectrum question

Postby deltarho[1859] » Mar 25, 2021 1:38

Come to think of it prma may not know what pseudocode is. Back in the ZX Spectrum days we talked about top-down programming and flow charts.

Pseudocode

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