Not a programmer, not a hardware guy, so can anyone explain to me the effect seen at the end of this video?
Small B-Asic demo - 6128 Plus only Irish demo from 1994.
https://www.youtube.com/watch?v=5wFpgyjGJDI (https://www.youtube.com/watch?v=5wFpgyjGJDI)
Links:
https://www.cpc-power.com/index.php?page=detail&num=11651 (https://www.cpc-power.com/index.php?page=detail&num=11651)
https://www.cpc-power.com/index.php?page=staff&lenom=Paul%20GARGAN (https://www.cpc-power.com/index.php?page=staff&lenom=Paul%20GARGAN)
https://www.cpcwiki.eu/index.php/Amstrad_User (https://www.cpcwiki.eu/index.php/Amstrad_User)
Not emulated - original hardware and software
Please note that the aspect ratio for this YouTube video is 16:9 but the CPC monitor
has an aspect ratio of 4:3 so you may wish to adjust your viewing device accordingly.
What do you mean?
"CPC PLUS" is still shown on the screen/overlays the screen display after a soft reset or when the DES Rom is launched - in fact the only way to remove it is to switch off the Plus. I've never seen that before.
Hi There
Do you mean the CPC PLUS sprites still being displayed on the screen!?
The demo does not clean up after it terminates
Plus features are still enabled by the ASIC so sprites still i ASIC memory..
I think!
/Ygdrazil
Quote from: ComSoft6128 on 18:21, 25 March 21
Not a programmer, not a hardware guy, so can anyone explain to me the effect seen at the end of this video?
Small B-Asic demo - 6128 Plus only Irish demo from 1994.
https://www.youtube.com/watch?v=5wFpgyjGJDI (https://www.youtube.com/watch?v=5wFpgyjGJDI)
Links:
https://www.cpc-power.com/index.php?page=detail&num=11651 (https://www.cpc-power.com/index.php?page=detail&num=11651)
https://www.cpc-power.com/index.php?page=staff&lenom=Paul%20GARGAN (https://www.cpc-power.com/index.php?page=staff&lenom=Paul%20GARGAN)
https://www.cpcwiki.eu/index.php/Amstrad_User (https://www.cpcwiki.eu/index.php/Amstrad_User)
Not emulated - original hardware and software
Please note that the aspect ratio for this YouTube video is 16:9 but the CPC monitor
has an aspect ratio of 4:3 so you may wish to adjust your viewing device accordingly.
Yes the text/sprites are still being displayed but a soft reset doesn't clear them - I thought reset cleared the memory?
Sprite memory is separate, on the ASIC.
As I don't think they changed the firmware from the original CPC, so the clean up of the sprites and their registers is not happening.
Thanks for the replies/info.
I didn't know the ASIC chip contained memory - 1K/2K or a few bytes?
Quote from: ComSoft6128 on 18:04, 27 March 21
Thanks for the replies/info.
I didn't know the ASIC chip contained memory - 1K/2K or a few bytes?
Probably 4K (16 sprites, 256 Bytes each.)
Since Plus software was intended to be on cartridge and a soft reset not possible (or if it was, it would boot back into the game), they probably though there was no need to clear the ASIC memory on a soft reset...
The ASIC memory is 16k, and is paged into 0x4000 to 0x7fff in the plus memory map when unlocked and then activated.
It not only contains sprite colour information, but also X and y coordinates for each sprite, sprite magnification factor, colour palette, DMA channel data, analogue controller data and more.
Quote from: Sykobee (Briggsy) on 10:40, 26 March 21
As I don't think they changed the firmware from the original CPC, so the clean up of the sprites and their registers is not happening.
mostly because to clean-up Asic, you need to unlock it first and Amstrad did not want to unlock full features at boot => YOU MUST PAY :D
I believe the unlock sequence is on the Wiki... :D
Quote from: Animalgril987 on 17:27, 28 March 21
The ASIC memory is 16k, and is paged into 0x4000 to 0x7fff in the plus memory map when unlocked and then activated.
It not only contains sprite colour information, but also X and y coordinates for each sprite, sprite magnification factor, colour palette, DMA channel data, analogue controller data and more.
So just to confirm; this is an extra 16K is on top of the 128K on the 6128 Plus giving a total of 144K?
Quote from: ComSoft6128 on 18:12, 28 March 21
So just to confirm; this is an extra 16K is on top of the 128K on the 6128 Plus giving a total of 144K?
It's not exactly memory, it's a mapping to Asic
there is 4096 half-byte for sprites (only lower nibbles are stored/readable) and a few registers (80 bytes for sprites on a 128 bytes area and a bunch of bytes for INT and DMA)
also some adresses are mirrored in the 16K area
this mapping is done in the #4000-#7FFF area so when Asic is mapped, you cannot access RAM below, you must disable mapping
Yes, it's as @roudoudou (https://www.cpcwiki.eu/forum/index.php?action=profile;u=1714) says, I didn't explain too clearly.