I have a Sinclair BASIC loader for my game which will CLEAR 32767, load a SCREEN$, LOAD ""CODE, and finally RANDOMIZE USR 32678. I have assembled the loader and the SCREEN$ into a TAP file - but how to I get zxbc.py to append its output to this TAP file? I can't seem to get it to work.

When I try:

Hi,

I have been frequently referring to the ZX Basic documentation while I have been programming. I find that at random (but multiple times a day) the search feature on the wiki returns no results for a short period which is quite frustrating. It's happened again right now. During though outages, luckily I can consult the markdown files on GitHub. However, they don't have a search function, which is useful so I do prefer the wiki.

I also notice that the boriel.com landing site frequently drops off the Internet late at night too. Can you perhaps set up some kind of host monitoring to determine just how big a problem this is, or maybe raise a support ticket with the webhost?

Thanks,

Patters

I have noticed while testing my program that the very first random number is always the same when the compiled program is loaded into an emulator. Subsequent ones are indeed random.

That first result is normal - you might think - because RND will be invoked at the same number of ticks after power-on each time. However, I use RANDOMIZE after an INPUT (which won't always be submitted at a consistent time by the user) before the first RND in the program is requested, so this should not happen. I presume this is a bug because after the first RND, it behaves as normal. If I deliberately insert a dummy RND before the RND values I need, then my program runs with the expected randomness.

Simple test case which demonstrates the issue:

Hi,

I'm trying to dim an array at a specific address which has been defined as a constant of type uinteger, unless I add 0 to the constant the code does not compile. 

const tileStart as uinteger = $4000+384

dim tile(0 to 255) as uinteger at tileStart         'this fails to compile with "Address must be a numeric constant expression" 
'dim tile(0 to 255) as uinteger at tileStart+0         compiles OK

print at 0,0;str(tileStart)

Am I missing something?

This is version: [v1.14.0]

Hello everyone,

I'm loving the discovery of zxbc and having a great time working on the game I always wanted to make! Thanks Boriel!

I've written code that randomly generates a map (well, its floor), which is stored in an array. To keep the size in memory down, I store the rows as bits and have written a routine to make reading this back in the game code nice and simple. I can easily determine if any given coordinate is floor or not. I'm really happy with this. Bit operators are brilliant!

I'm now at the stage where I need to start putting my graphics on the screen. Using the map floor as a reference, I intend to display the walls and floor of the dungeon using 3x3 character blocks, with each successive row overprinting the bottom of the row before it. This way I should be able to display a 9 x 9 view with a pseudo 3D view and the player in the middle.

Using the floor as the starting point, what's I'm trying to work out right now is the best way to could assemble the whole view of this and print it to the screen in one go so the player doesn't see it redraw tile by tile. As the game is turn based, I don't mind if preparing and moving the updated screen isn't instant.

I've thought of two methods:

1. Dynamically create a string and colour it in using control codes, to set everything up that is then printed in one go.
   
2. Scroll the screen, a tile in whatever direction needed and then fill in the space.
   

My program is calculating attribute memory addresses for screen characters. In the interests of only DIMing what I need, I store the screen coordinates as UBYTE since I only need numbers from 0-32 at most.

I have spent a long time to find that the compiler doesn't perform the maths properly when these UBYTE variables are used with larger numbers in a calculation - even though I'm never asking for that UBYTE variable to be made any larger. See this example:

In Sinclair BASIC you can DIM the length of a string using
DIM a$(5)

If I try something similar in Boriel BASIC
DIM a$(5) AS STRING

the compiler seems to interpret this as an array declaration.

Sometimes it's useful to declare the largest expected length of a string if you want to build it up of component pieces. e.g. In Sinclair BASIC:

It seems as if the compiler gets this wrong when the x coord is greater than 27. See example:

I'm having trouble passing a string to a Function in order to edit it. The code which works fine outside of a Function just won't modify the string inside the Function for some reason. Any idea what I'm doing wrong?

In my program PAUSE doesn't seem to work. Is that normal? I would find it useful to delay execution a bit while my program prints an error on screen when the result of an INPUT isn't compliant. I can't see any mention of PAUSE in the wiki. I mean I can use a FOR loop to count to 10,000 instead, but I thought the aim of Boriel BASIC is to be a faster superset of Sinclair BASIC so it's surprising this seems to be missing.