Friday, December 4, 2020

Mica Computer 6502 64k

The new hardware prototype board is sort of done, it allows for the extra ram now and its much less messier than it was before.


this as you can see has the SCART lead on the side, for that lovely RGB out, 15khz (50hz PAL) screen
NTSC signals aren’t in yet, as i still haven’t worked out the timing for this yet.

Right now the 8MegaByte isn’t accessible, possibly due the the configuration or my wiring, but we o have access to 4Mb.

The system s runing at 450Mhz, access to SDCARD

This also has a nice feature of a joystick port…… that will read Amiga Mouse, left and right mouse button


As you can see the mouse pointer is there, and the system saying Sidbox 5 computer.

This is Mica.
Running 6502 code, with 64k ram, but do plan to run 256k available ram.
a rom space thinking about 8k or 16k
this rom will contain some functions and so far our testing has worked!

thanks to the work of by Jesper Gravgaard / Rex of Camelot

This helped alot! speeding up debugging the hardare and the computer memory mapping.

So we have our machine that boots up with its own internal rom, (1k so far and thats just for the boot up and logo!! hmm i’ll definetly be doing some stripping down and optimising ofcourse, we got functions and features to pack into an 8k or 16k rom)

Turn on the computer (or switch to Mica mode) runs the bios, we see this…

after a short animation:
this shows up (tho we may change this later)


so when the screen shows, we’re normally used to just slapping your keys and writing the classing
10 print “hello world”
20 goto 20

Well since our rom doesnt come with a BASIC, (I hope I can find one though)
since I need to find a way to get our keyboard to feed this mica! so far only the joystick port is readable!

The work continues.

This machine seems to clock between 1Mhz to 3Mhz depending on whats on the display..