Print Page - cpctelera : startaddress is 0x0100 ?

Title: cpctelera : startaddress is 0x0100 ?
Post by: funkheld on 20:03, 20 November 20

Hi good afternoon.

im wondering that the starting address at cpctelera can be so low. Why ?
normally you can only start at 0x4000.

greeting

spritedemo:
------------------------------------
PROJNAME := sprites
Z80CODELOC := 0x0100
------------------------------------

Title: Re: cpctelera : startaddress is 0x0100 ?
Post by: ervin on 23:34, 20 November 20

Most cpctelera programs disable the firmware. Cpctelera has a command to do this. Disabling the firmware allows us to use the ram before 0x4000.

Title: Re: cpctelera : startaddress is 0x0100 ?
Post by: funkheld on 23:37, 20 November 20

which system commands can then no longer be used?

greeting

Title: Re: cpctelera : startaddress is 0x0100 ?
Post by: awergh on 00:20, 21 November 20

Quote from: funkheld on 23:37, 20 November 20
which system commands can then no longer be used?

Have a look at the cpctelera documentation.
https://lronaldo.github.io/cpctelera/files/readme-txt.html (https://lronaldo.github.io/cpctelera/files/readme-txt.html)

For example in cpct_drawStringM0 provides a warning:
Do not put this function's code below 0x4000 in memory. In order to read characters from ROM, this function enables Lower ROM (which is located 0x0000-0x3FFF), so CPU would read code from ROM instead of RAM in first bank, effectively shadowing this piece of code. This would lead to undefined results (typically program would hang or crash).

CPCWiki forum

General Category => Programming => Topic started by: funkheld on 20:03, 20 November 20