 lib environment
 lib bfhdr
 lib macdefs
 sttl AT Driver Map (TSC Internal)
 pag
 data
*
* at_map - Map logical address into physical address
*  (uistrt) - Starting address
*  A - High 4 bits
*  X - Low 16 bits
*
 global at_map
at_map pshs y
 ldd bfadr,y set up address on stack
 pshs d
 leas -1,s space for high byte
 pshs cc save interrupt mask
 seti mask interrupts!
 lda sysmap+XBUF save current XBUFFR address
 sta tempXB
 lda bfxadr,y map in user
 jsr UFE_008 mapxbf
 ldx #umem-(USRLOC<<12)+XBUFFR
 ldd 2,s restore logical address
 jsr UFE_011 mapupg2 map user page
 std 1,s
 lda tempXB restore XBUFFR mapping
 jsr UFE_008 mapxbf
 puls cc,a,x,y,pc return
*
tempXB fcb 0 save XBUFR map
