Re: Gforth BLOCK 0

IIRC 0 isn't a valid block number: for instance,

http://forth.sourceforge.net/standard/dpans/dpans7.htm#7.6.1.1790 LOAD 
says "An ambiguous condition exists if u is zero or is not a valid block 
number."

I believe in some systems blocks were actually the raw disk, so the 
bootloader would be in block zero and thus it wasn't available for 
source code? I could be totally wrong about that.

--Josh

On 8/6/2022 7:17 AM, shtps via Gforth discussion and announcements wrote:
> Hi,
> 
> I'm relatively new to Forth and I'm wondering if I'm doing something wrong or if this is intended behavior or if this is a bug. I'm using gforth on GNU/Linux.
> 
> Executing the following gives me an error message and creates an empty 0 byte file called blocks.fb:
> 
> s" Hello world!" 0 block place update save-buffers bye
> 
> I have attached the backtrace but it doesn't seem very helpful, all it says is invalid memory address. So I then delete the file blocks.fb and try again, but this time with block 1 instead:
> 
> s" Hello world!" 1 block place update save-buffers bye
> 
> and it successfully writes into the block and we can verify that it did indeed write into it by starting gforth again and executing:
> 
> 1 block count type Hello world! ok
> 
> So maybe block 0 will work now? I try to write into it again:
> 
> s" weird..." 0 block place update save-buffers bye
> 
> No errors this time, but when I start gforth again and try to read from it I don't get the expected output:
> 
> 0 block count type ok
> 
> So I looked at the blocks.fb file in a text editor and "weird..." was written into it correctly and after a while I've figured that the following works after starting gforth again:
> 
> 1 block drop 0 block count type weird... ok
> 
> To me this seems like a bug where "0 block" doesn't initialize something that "1 block" does. Either that or I'm using blocks the wrong way. Unfortunately I could not find any simple examples on how to use blocks so I'm just going off the docs and a few scraps of information on the internet that I could find.
> 
> Best Regards,
> shtps