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Propeller as VGA Driver — Parallax Forums

Propeller as VGA Driver

Peter J. FischelPeter J. Fischel Posts: 28
in Propeller 1
Hi,  I have been working on a Z80 computer and intend to run CP/M on it.   have been thinking of using the Propeller to drive a VGA display and act as a terminal emulator.  From looking at Pocketerm it seems this can be done yet would prefer to build this onto my protoboard. I know there are a lot of objects for vga but not really getting the specifics.
My goal is to get 80 x 24 character display as it seems pretty common for CP/M.  I have also looked at the Character Rom and many of those characters and non standard.  Both 800x600  and 640x480 resolutions seem dorky for accomplishing 24 rows.  80 columns doesn't seem too unreasonable. 
So, I have two questions I hope you can help me with.
Is 80 x 24 practical to be driven by the Propeller using character rom? 
Can the character rom be overwritten with new characters?
Thanks,Peter

Comments

  • potatoheadpotatohead Posts: 10,261
    If it were me, I would get the contents of that ROM and load them into Propeller RAM.

    80x24 VGA is possible.
  • Peter J. FischelPeter J. Fischel Posts: 28
    Thanks potatoHead! Good suggestion. I found a Kaypro II character rom and will use that.
    Peter
  • SapphireSapphire Posts: 496
    Kuroneko did an excellent 80x25 (720x400) VGA driver here: https://github.com/konimaru/waitvid.2048
    The 9x16 characters can be reprogrammed.
  • Toby SeckshundToby Seckshund Posts: 2,027
    I did this a while back with a grant Searle Z80 circuit and a Prop1 to handle the serial interface it required (he originally used an AVR to do 80x25 but in PAL). I think that I may have gone for Kye Dos in the EEPROM and then load up the terminal from that. I had grand plans to use the SD as the main storage (Z80 can talk to a CF card).
    As with all things I make I have not touched it for about 2 years now ...
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