Spectrum Computing

If I've understand it should be something as (for AND) 10 IF a THEN IF b THEN IF c THEN PRINT "oki doki" and for OR 10 IF NOT a THEN IF NOT b THEN IF NOT c THEN GOTO 30 20 PRINT "oki doki" 30 STOP ? That’s correct. Put the expression most likely to fail first, then the others do...

You are copying 1 too many bytes to LAYER 0 and therefore clobbering the start of the paging routine after the attributes. LDIR counts down to zero. You get this right for attributes but by then you’ve tried to stuff 6145 bytes into the pixel area. Off by one errors are almost the only sort I make, ...

Miktor wrote: ↑Sat Apr 23, 2022 4:29 pm The ZX Spectrum screen layout makes my tiny little brain hurt.

It’s done that way to save 5.25K of attribute memory - without it, the 16K Spectrum would’ve had less than 4K free for BASIC.

Use my MultiSearch from Your Spectrum issue 12

http://www.users.globalnet.co.uk/~jg27p ... r12_47.htm

I also find it handy for eliminating spurious %s in NextBASIC after renumbering.

https://simon.mooli.org.uk/nextech/index.html#NoGo

Two cheers for compatibility!

equinox wrote: ↑Fri Nov 03, 2023 5:46 am suppose I only wanted to reserve exactly one byte, could i do like CLEAR 65534

Yes.

The byte reserved will be at 65535.

Enjoy POKEing it.

Nine Tiles, what were you thinking? You were thinking "oh hell it has to be done by Thursday". I know John Grant. Your mockery is misplaced. Clive Sinclair flatly refused to spend a few thousand pounds to have the BASIC intended for a 1K computer refactored for 48K or more, insisted on mi...

By ‘startup’ I was referring to the menu in the anti-brick scheme, before NextZXOS (or Acorn or other cores) is loaded. Press space immediately after powering up to see that one and adjust the defaults. Let us know if it helps. You can always change the joystick configurations with NextREG 5. Mask o...

Sinclair paid Timex £34 for each complete boxed 48K Spectrum system according to Tony Tebby who wrote the QL OS there in 1983. The QL was sufficiently profitable at £199 retail for Amstrad to restart QL production after their takeover, to satisfy demand from Dixons who I understand expected at least...

I think someone on youtube may have mocked up a tape recorder that simply played its track faster, and loaded the games quicker -lol I wouldnt know how to search for that on youtube but ill give it a try. The SAM cassette loader (ROM source freely available) adjusts to the relative speed of the CPU...

Several places? The startup menu, normally skipped, sets the defaults. These persist till you change them. The NextZXOS menu lets you over-ride them temporarily during a session. It shows what you set as default, then lets you change that. It seems sensible to have both. The options exist because th...

Line 48 is entirely redundant and can safely be omitted, BTW. Incidentally the title is misleading. There is no error in nextBASIC shown here, just one common beginner misunderstanding about the meaning and purpose of % there. I have explained that more fully in another reply here. I think a lot of ...

The suggestion fixed one error, the use of x in an integer context when %x was required, but introduced another of the same type. 60 let %a=% bank 20 peek x : print %a Now you are assigning to %a so printing it makes sense. Alternative fix: 60 let a=% bank 20 peek x : print a Or cut out the middle-m...

Your code does not work because you are setting the variable b and then using the independent variable %b in the integer PEEK expression. The % is effective on all variable references till the end of the expression e.g. up to THEN, colon, comma or enter. Set %b instead of b and it will work as you e...