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

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