Implementation of a popular 8-bit computer on a Cyclone IV based DE2-115
The monitor on the left is my Linux workstation, it's the one on the right thats more interesting
This is an early implementation of my video subsystem, I cheated and used duel ported BRAM, the real deal kicked the CPU off the bus; thus, the 6502 was in a kind of wait state except during blanking. Yep that's VGA! (I don't have any composite monitors anymore) VGA was hard enough but I so wanna sort out HDMI
Text mode works
The ROMs are "programmed" during synthesis (I'm not using external flash etc.). I used xxd to format the file:
~~xxd -ps -c1 3410036.bin > AppleII_crom.txt The roms can be dumped from your Apple II or downloaded
from http://ftp.apple.asimov.net/emulators/rom_images/
The CROM (character ROM) begins with 00 1c 22 2a 2e 2c 20 1e... Look for a file named 3410036.bin The file contains bitmaps of the character set.
0x00 0x1c XXX 0x22 X X 0x2a X X X 0x2e X XX X 0x2c X XX 0x20 X 0x1e XXXX
For the main ROM APPLE2_.ROM from https://ftp.apple.asimov.net/emulators/rom_images/ might be a good choice.
xxd -ps -c1 AppleII/APPLE2_.ROM > AppleII.txt~~
note: The ROMs are checked in now.
My DE2-115 has an old fashion PS/2 connector and I have a model M keyboard as shown in the pictures. AFAIK all keys are working including esc, tab, arrows, ctrl, del, etc. I have rigged the break/pause key as a reset.
VGA -> HDMI (my last VGA monitor is looking tired)
I have not implemented the graphics modes yet, so text only.
