MiSTer (FPGA) New Core: Vic-20 (Loading .CRTs)
13Commodore Vic-20
MiSTer FPGA running VIC20_20180514.rbf
New core ported to MiSTer FPGA by Sorgelig from Atari-Forum.
Cartridges played in this video:
- Frogger
- Gorf
- Radar Rat Race
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Notes from ViC-20 MiSTer Github:
Commodore VIC-20 has very messy and confusing expansions, so you need to be familiar with this computer to know how to run different cartridges and correct RAM expansion for different games. Multi-part cartridges only add more mess. Some cartridges have loading address in the first 2 bytes, some haven't so you only can guess where to load (usually loading address is written in the file name) the cart.
If the cartridge has one of these exact sizes: 2048, 4096, 8192, 16384 then it has no header.
If size is 2 bytes more of one of these sizes then it has a header with loading address.
You can find many dumps of multipart carts as a single CRT file - in most cases, these dumps won't work as these parts usually aren't loaded into connected regions and must be loaded separately!
Sorgelig set following extension convention:
- .CRT - extension for cartridges with header.
- .CR4, .CR6, .CRA, .CRB - extensions for cartridges without header
with most common loading addresses $4000, $6000, $A000, $B000 respectively.
If you find the headerless cartridge with other loading address, then you need to add 2 bytes at the beginning with loading address in some HEX editor and effectively convert it into .CRT
You won't find the cartridges with CR4/CR6/CRA/CRB extensions. All cartridges you will find will have CRT extension regardless of having the header or not. So you need to rename them accordingly if they have no header!
The best practice is to use only carts with a header!
Since many cartridges are multipart cartridges, there is no autostart procedure. You need to load all parts from OSD and if starting address is $A000(SYS 40960) then simply press CTRL+F11 to start. If starting address is different, then follow the instruction of the cartridge. Usually, it's SYS {address} command.
RAM expansions aren't universal. Turning on all expansions won't automatically make VIC20 compatible with all games. So, you need to find the info about specific game RAM requirement if it doesn't run. Or try different options.
Good luck in playing with this Zoo :)
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Mister FPGA Wiki Project:
https://github.com/MiSTer-devel/Main_MiSTer/wiki
Mister Forum discussion:
http://www.atari-forum.com/viewforum.php?f=117
Sorgelig's MiSTer Cores:
https://github.com/MiSTer-devel
MiSTer Facebook page:
https://www.facebook.com/groups/1870135613286506/
The video clip was captured and uploaded by AVerMedia Game Capture HD II.