collapseos/arch/z80/rc2014/blk/602
Virgil Dupras 7001446212 Complete overhaul of recipes
Recipes contain bits and pieces of hardware-related knowledge, but
these bits feel sparse. I've been wanting to consolidate hardware-
related documentation for a while, but always fell at odds with the
recipes organisation.

We don't have recipes anymore, just a /doc/hw section that contains
hardware-related documentation which often translate to precise
instructions to run Collapse OS on a specific machine.

With this new organisation, I hope to end up with a better, more
solid documentation.
2020-10-30 20:39:39 -04:00

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0x80 CONSTANT ACIA_CTL ( IO port for ACIA's control register )
0x81 CONSTANT ACIA_IO ( IO port for ACIA's data registers )
0x20 CONSTANT ACIA_BUFSZ ( SZ-1 must be a mask )
( Address in memory that can be used variables shared
with ACIA's native words. 4 bytes used. )
CREATE ACIA_MEM SYSVARS 0x70 + ,
( Points to ACIA buf )
: ACIA( ACIA_MEM @ 2+ ;
( Read buf idx Pre-inc )
: ACIAR> ACIA_MEM @ ;
( Write buf idx Post-inc )
: ACIAW> ACIA_MEM @ 1+ ;
( This means that if W> == R>, buffer is full.
If R>+1 == W>, buffer is empty. )