Video direct access

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tuxie
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Video direct access

Post by tuxie » Sat Mar 17, 2018 9:48 am

Hello Guys,

i need you help.

I am working on the FPGA Booster for the ST (dont want tell the name) so for wie can access the Rom, the Ram. Now we want to make some Assembler test routines to test the access to some Hardware parts.

At the moment we habe no TOS available, the Core loads a Booloader from the flash, this Bootloader can be filled by some 1kbyte assembler code.

Now whe want do the following.

1. Init the Video Hardware
2. Switch to white background
3. when click a key the display should switch to black and after click again, witching again back to white

I have searched the documentation how it could work but nothing found. Possible is the sourcecode of emutos. But this confuse me to muh because C ^^

Regards

Petari
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Re: Video direct access

Post by Petari » Sat Mar 17, 2018 10:10 am

Harder part in this will be keyboard read.
Instead EmuTOS I have disassembled TOS 1.04, where can see well early stage HW init code - in ASM. I can post it here.
But I guess that will need more assistance.
Test should include more than just white-black color, and is not clear want you keep black bgr. while bitmap part goes white, or everything white - but later is not good idea, since you can do it by only setting color 0 to white. So, better is to write some pattern in video RAM. All it can fit in 1KB for sure .
There is 2 kind of people: one thinking about moving to Mars after here becomes too bad, the others thinking about how to keep this planet habitable.

tuxie
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Re: Video direct access

Post by tuxie » Sat Mar 17, 2018 10:44 am

Only what we want todo is to check if interrupts are working.. so i thought we do a small code to wait until a keyboard key is preset and to check if its working the display should change the color

Petari
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Re: Video direct access

Post by Petari » Sat Mar 17, 2018 1:13 pm

Sorry, but it is not clear is there active TOS ROM.
"so for wie can access the Rom" , then : "At the moment we habe no TOS available, the Core loads a Booloader from the flash"
The question is: is it jumps right after reset to Booloader (really should be more precise with typing) code or it jumps to TOS ROM start ?
If there is no TOS ROM, then initializing all necessary HW - like RAM, MFP. IKBD, interrupts etc. must be performed, and that's pretty much to do.
There is 2 kind of people: one thinking about moving to Mars after here becomes too bad, the others thinking about how to keep this planet habitable.

tuxie
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Re: Video direct access

Post by tuxie » Sat Mar 17, 2018 1:43 pm

This FPGA CPU starts something like a Bootloader, this is a 1kb assembler code. And in this code the TOS gets mapped and accessed. With this short code we can access the hardware without running TOS. So nothing is initialized.

Petari
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Re: Video direct access

Post by Petari » Sat Mar 17, 2018 2:53 pm

That's bad idea. And when you say "starts something like a Bootloader" then make it act like that - so like it is loaded from disk.
Otherwise must perform plenty of HW initialization what TOS performs normally - and it is there.
You want to "check if interrupts are working" - certainly work not when TOS is not activated.
There is 2 kind of people: one thinking about moving to Mars after here becomes too bad, the others thinking about how to keep this planet habitable.

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exxos
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Re: Video direct access

Post by exxos » Sat Mar 17, 2018 3:41 pm

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https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
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tuxie
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Re: Video direct access

Post by tuxie » Sat Mar 17, 2018 4:20 pm

Yeah i will... thx

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