VRAM BASIC writing

By sergarbes

Expert (98)

Аватар пользователя sergarbes

28-07-2021, 12:56

Hi,

I am practicing a bit of basic. I am reading and testing that putting the value & H44 in the first byte of palette 6 of the VRAM makes the characters 0 to 7 appear in blue. Why does this happen? There is literature to read on the subject ?

VPOKE BASE(6), &H44

Thanks in advance!

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By thegeps

Paladin (864)

Аватар пользователя thegeps

28-07-2021, 13:21

Yep, screen1 characters are grouped by 8. Infact screen1 color table is 32 bytes long. Each byte belong to a group of 8 chars 0-7,8-15,16-23 and so on. High nibble is foregroud color, low nibble is background color

By thegeps

Paladin (864)

Аватар пользователя thegeps

28-07-2021, 13:24

About litetature you'll find all you need st MAP, at this link (scroll down till the video chips section):

http://map.grauw.nl/resources/

By sergarbes

Expert (98)

Аватар пользователя sergarbes

28-07-2021, 20:15

thegeps wrote:

Yep, screen1 characters are grouped by 8. Infact screen1 color table is 32 bytes long. Each byte belong to a group of 8 chars 0-7,8-15,16-23 and so on. High nibble is foregroud color, low nibble is background color

Thanks!

By sergarbes

Expert (98)

Аватар пользователя sergarbes

28-07-2021, 20:15

thegeps wrote:

About litetature you'll find all you need st MAP, at this link (scroll down till the video chips section):

http://map.grauw.nl/resources/

Cool!