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MiSTer-devel / AtariST_MiSTer

Atari ST/STe for MiSTer
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Request: Can ET4000 graphics be added to the ST core? #24

Open officer960 opened 11 months ago

officer960 commented 11 months ago

ET4000 was implemented to the AO486 core. Would it be possible to add this to the Atari ST core like the Viking graphics option?

sorgelig commented 11 months ago

Probably can, but it's beyond my capability. I don't know ST hw well. If i understood right ET4000 addon is aftermarket homebrew addon which gives more complexity to understand how it was connected and how it was working.

officer960 commented 11 months ago

The Nova card was an aftermarket add on that attached to the VME port on MSTE and TT030. There were also cards that were attached via the Mega Bus on the MST. The ET4000 cards from PC's of the era (ISA) can be fitted to the VME bus with a relatively simple converter: (https://www.atari-forum.com/viewtopic.php?t=40930) and if my understanding is correct function as a Nova card. They do require drivers which are available, and I believe EmuTOS has a form of the drivers built in: (https://www.exxosforum.co.uk/forum/viewtopic.php?f=50&t=6427)

The PiSTorm project for Atari ST just recently got ET4000 graphics added and might be a good source for how its "connected". It should be possible (easy for me to say) as the core in the AO486 has the ET4000 code already done if it can fit in the ST's MiSTer core.

sorgelig commented 11 months ago

As you pointed out it was for TT030 model which has much more features like 68030 with FPU and MMU not implemented in core. So drivers and software may expect 68030 CPU and other TT features.

sorgelig commented 11 months ago

One thing often get lost in such discussions: MiSTer's primary goal is to re-create HW made from original manufacturer to be able to run games and software targeted to original HW. This is basically what 99% users need. I know there are some popular retro systems with communities still adding some modern addons. In most cases such addons are useful only for real HW to get some fun. Usually it has no software besides couple technical demos, so from historical point of view it has no value. In general i'm not against such addons, but to develop such core beyond original HW we need a dedicated developer(s) who knows this system very well and able to add all such aftermarket features. In other words such additional features should be developed by community of that system.