1. printer test - Reply
Michael J Doscher asked:
> How do you determine if the printer is on line or not ?
I think Wally was absolutely right, why don't you listen to your printer?
But just in case, I also translated Irv's proposition. Jiri
-- snip ------------------------------------------------------------------------
-- printer.ex
-- j.babor at gns.cri.nz
include machine.e
function printer_status(integer printer_number)
-- return printer status
-- printer_number is 1 for lpt1, 2 for lpt2, etc
-- status byte bits (1 & 2 are not used):
-- -- 7 --- ---- 6 ---- -- 5 --- -- 4 --- -- 3 -- --- 0 ---
-- not busy acknowledge no paper selected i/o err. timed-out
sequence rl -- list of register values
rl = repeat(0,10)
rl[REG_AX] = #0200
rl[REG_DX] = printer_number-1 -- 0..2 -> lpt1..lpt3
rl = dos_interrupt(#17,rl)
return floor(rl[REG_AX]/256)
end function
function printer_ok(integer printer_number)
-- return 1 (true) if printer is selected, has paper,
-- and no I/O or time out error has occurred
integer status
status=printer_status(printer_number)
return and_bits(status,#10) and not and_bits(status,#29)
end function
-- example ---------------------------------------------------------------------
? printer_status(1)
? printer_ok(1)
