Qprint

 BBS: Inland Empire Archive
Date: 04-15-92 (13:37)             Number: 63
From: DON KROUSE                   Refer#: NONE
  To: BILL BEELER                   Recvd: NO  
Subj: Qprint                         Conf: (2) Quik_Bas

BB>In a message to John Gallas <07 Apr 92  17:51> Don Krouse wrote:
BB> DK> DEFINT A-Z
BB> DK> DECLARE SUB PrintFast (Rows%, Col%, Msg$, atrib%)
BB> DK> PrintFast 5, 25, "This is Pretty Fast", 31

BB> DK> SUB PrintFast (Rows%, Col%, Msg$, atrib%)
BB> DK> place% = ((((Rows - 1) * 80) + Col) - 1) * 2
BB> DK> DEF SEG = &HB800 ' Use &HB000 for mono systems
BB> DK> FOR i = 1 TO LEN(Msg$)
BB> DK>   POKE place%, ASC(MID$(Msg$, i, 1))
BB> DK>   POKE place% + 1, atrib
BB> DK>   place% = place% + 2
BB> DK> NEXT i
BB> DK> DEF SEG
BB> DK> END SUB

BB>Don,

BB>You might try putting a STEP 2 at the top of the FOR loop and discard the
BB>incrimentation of place...it *might* speed it up even more.

Hi Bill,

It DEFINITLY does speed it up.

After reading your message I fired up QB, inserted the STEP 2 and remmed
out  'place% = place% + 2. I then quickly compiled  and ran the test.

When I read the output file I almost dropped my coffee cup in my lap,
the times were twice as fast with the modification. Then I realized that
the reason that the times were twice as fast was because the string was
half as long. The FOR/NEXT counter is the length of the string being
printed therefore using STEP 2 prints every other character.

I did try using STEP 2 with the memory address as the counter but the
additional math required to determine what character to print slows it
down about 3% to 5% depending on the string length. (see below)

I do appreciate the thought, if you have any more I'd like to here them.

Don

Modified (slower) version - note (\) integer division

SUB PrnFast (Rows%, Col%, Msg$, atrib%)
start% = ((((Rows - 1) * 80) + Col) - 1) * 2
ending% = (place% + LEN(Msg$) * 2) - 1
DEF SEG = &HB800
FOR i = start% TO ending% STEP 2
   POKE i, ASC(MID$(Msg$, ((i - start%) \ 2) + 1, 1))
   POKE i + 1, atrib
NEXT i
DEF SEG

END SUB

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 * Origin: Silver Lake Systems * Bothell,WA (1:343/58)