collapseos/arch/z80/sms/blk/621

: (ps2kcB) ( for port B )
	( Port B TL is bit 2 )
    _D2@ 0x04 AND IF 0 EXIT ( nothing ) THEN
    0 _THB! ( Port B TH output, low )
    _D1@ ( bit 7:6 go in 1:0 ) 6 RSHIFT ( n )
    _D2@ ( bit 1:0 go in 3:2 ) 0x03 AND 2 LSHIFT OR ( n )
    1 _THB! ( Port B TH output, high )
    _D1@ ( bit 7:6 go in 5:4 ) 0xc0 AND 2 RSHIFT OR ( n )
    _D2@ ( bit 1:0 go in 7:6 ) 0x03 AND 6 LSHIFT OR ( n )
	2 _THB! ( TH input ) ;
sms/kbd: PS/2 driver WIP 2020-05-20 10:52:48 +10:00			`: (ps2kcB) ( for port B )`
			`( Port B TL is bit 2 )`
sms: simplify and solidify ports-related drivers Add _TRA!, _THA!, _TRB!, _THB! routines to easily handle those pins' value without stepping on other pins like the drivers previously did. For SDC driver, it's going to be important soon because it turns out that I can't get away with "always on" CS, so I'll need a scheme where it's important that TH/TR pins have stable values. 2020-11-03 10:53:57 +11:00			`_D2@ 0x04 AND IF 0 EXIT ( nothing ) THEN`
			`0 _THB! ( Port B TH output, low )`
			`_D1@ ( bit 7:6 go in 1:0 ) 6 RSHIFT ( n )`
			`_D2@ ( bit 1:0 go in 3:2 ) 0x03 AND 2 LSHIFT OR ( n )`
			`1 _THB! ( Port B TH output, high )`
			`_D1@ ( bit 7:6 go in 5:4 ) 0xc0 AND 2 RSHIFT OR ( n )`
			`_D2@ ( bit 1:0 go in 7:6 ) 0x03 AND 6 LSHIFT OR ( n )`
			`2 _THB! ( TH input ) ;`