Commands summary
.... both versions.... lpt_getba returns base address of selected LPT lpt_setba <addr> selects LPT at base address <addr> lpt_rddata returns LPT data register value lpt_rdstat returns LPT status register value lpt_rdctrl returns LPT control register value lpt_wrdata <val> writes <val> to LPT data register lpt_wrstat <val> writes <val> to LPT status register lpt_wrctrl <val> writes <val> to LPT control register ... only in version 3.0 .... lpt_rdreg <offset> generic register read at (base_address + offset) lpt_wrreg <offset> <val> generic register write at (base_address + offset) lpt_setport <id> selects LPT<id>, where <id> = 1,2,3,...; lpt_getport returns 1,2,.... (lpt_getba returns -1 if lpt_setport points to a non-existing LPT) (lpt_setba now accepts a 32-bit value) ----Basic startup code
console show wm withdraw . load lpttcl set ver [package require lpttcl] puts [format "LPTTCL, version %s" $ver] puts "---------------------" puts [format "Current port: LPT%d" [lpt_getport]] puts [format "Base address: 0x%08X" [lpt_getba]] puts " " puts [format "Data register: 0x%02X" [lpt_rdreg 0]] puts [format "Status register: 0x%02X" [lpt_rdreg 1]] puts [format "Control register: 0x%02X" [lpt_rdreg 2]] puts [format "Extended control register: 0x%02X" [lpt_rdreg 0x402]]and its output on a console:
LPTTCL, version 3.0 --------------------- Current port: LPT1 Base address: 0x00000378 Data register: 0xAA Status register: 0x78 Control register: 0x0C Extended control register: 0x15UtilitiesNote that in ver. 3.0 you can now perform a quick autoscan of available LPT ports:
proc LPTscan {{nmax 8}} {
for {set i 1} {$i < $nmax} {incr i} {
lpt_setport $i
if {[lpt_getba] == -1} {
puts "LPT$i absent"
} else {
puts "LPT$i present"
}
}
}We made some profiling of access speed (when you insert real code in the loop, it goes slower); note that the test is compatible with both versions.
proc toggle {num} {
for {set i 0} {$i < $num} {incr i} {
lpt_wrdata 0x55
lpt_wrdata 0xAA
}
}
proc getmaxfreq {{ntimes 10000}} {
set tt [time {toggle $ntimes}]
scan $tt %i tt
set mf [expr (2000 * $ntimes / $tt)] ;# 2 writes, expressed in kHz
puts "Max frequency is $mf kHz"
}Some results (using freewrap 5.4, based on Tcl/tk 8.3.5) using getmaxfreq:- laptop, P4 M 1.6 GHz, XP prof.: around 130 kHz
- desktop, P4 2.4 GHz, XP prof.: around 210 kHz
meh: Are there any plans for a Linux version of LPTTCL? If not, can anybody refer me to a page showing how to use applicable LPT pins as 'bits' (on/off state, on sends a small voltage, off sends none)
distatica: meh, if you are referring to individual pin access under Linux, check out the Parapin library located here: http://parapin.sourceforge.net/
If not, please delete this.dec: meh, I'm currently working on a package that gives access to the parallel port on Linux, Ubuntu 7.10 distribution, it makes use of the ppdev user space driver. It seems to work OK so far. email me at derek dot philip at tesco dot net and I'll forward you the source.Category Printing | Category Windows
