This may be just more of the same problem, but it appears Virtual T runs too fast when printing to the screen as well.
[image: image.png] I noticed this because the BASIC loader <https://github.com/hackerb9/co2do/> I made for .co files is superduper slow and the reason is (partly) due to constantly printing the status. If anyone knows a fast way to display on the screen, please do let me know. To test, I printed strings of different lengths and measured the elapsed time. On my actual Tandy 200, it was a linear relationship for strings from 0 to 39 chars: n×16÷9+5. Virtual T seems to be going about twice as fast with a speed of about n+3 seconds for printing an n-character string 1000 times. —b9 On Mon, Feb 9, 2026 at 3:39 PM B 9 <[email protected]> wrote: > Virtual-T seems to be running too fast for me compared to real hardware > (Tandy 200). I could be doing things wrong, so it’d be helpful if other > people checked this out as well. > > Experimentally, my Tandy 200 takes 10 seconds to count to 3535. > > FOR T=1 TO 3535: NEXT > > When I do the same thing on Virtual-T’s emulated T200 it takes only 6 > seconds. > Machine Time to count to 3535 > Genuine T200 10s > Virtual-T 1.7 T200 6s > Virtual-T 1.7 M100 5s > > Is the same thing true for other folks with real hardware? What about the > Model 100 and Tandy 102 (or other more esoteric of the Kyotronic kin)? > > Second thing: REX# seems to slow my machine down significantly when I do > not have an Option ROM activated. It is completely repeatable. Is this a > known issue? I tried using the emulated REX in Virtual T, but I must have > an old version as it only had REX and REX2 listed, not REX#, and those > didn’t cause any slowdown. > Machine and REX# setup Time to count to 3535 > Genuine T200 with REX# De-installed 10s > Genuine T200 with REX# Installed, but no Option ROMs activated 16s > Genuine T200 with REX# Installed and any Option ROM activated 11s > > Finally, here’s a program that makes it easy to run timing tests > repeatedly. > > 0 REM Speed Check4 COUNT=3535 ' T200 takes 10s to 35355 PRINT"Counting up > to";COUNT6 PRINTTIME$10 T1$=TIME$20 FOR T=1 TO COUNT: NEXT30 T2$=TIME$: > PRINTT2$40 H1$=MID$(T1$,1,2)50 M1$=MID$(T1$,4,2)60 S1$=MID$(T1$,7,2)70 > H2$=MID$(T2$,1,2)80 M2$=MID$(T2$,4,2)90 S2$=MID$(T2$,7,2)110 > H2=VAL(H2$):H1=VAL(H1$)120 M2=VAL(M2$):M1=VAL(M1$)130 > S2=VAL(S2$):S1=VAL(S1$)150 IFS2<S1THENS2=S2+60:M2=M2-1:GOTO 150160 > IFM2<M1THENM2=M2+60:H2=H2-1:GOTO 160170 IF H2<H1 THEN H2=H2+12: GOTO 120180 > H=H2-H1: M=M2-M1: S=S2-S1190 PRINT"Ran";COUNT;"loops in";200 > PRINTUSING"##h##m##s";H;M;S > > Please let me know what you find. Thanks all! > > —b9 >
graph.do
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