Dear reader,
I'm sorry to bother you again, but the hax0r1ng of the TI83
ROM I'm doing now pays off: I've found a way to increase the TI83's speed
without any modifications. However, the speed benefit you get is rather big, but
the area of effiency is small. That was a hard sentence, but it means: you save
27 clockticks on almost every romcall you make (of course I'm talking about ASM
now). My old 8086 has figured out that 186 (!) romcalls that were defined by
Texas Instruments(c?) were not optimized for speed. The memory locations that
were given by them point to some sort of storage area where all romcalls are
*called again* -> the Z80 has to process a new 'call' instruction (17
clockticks) and another 'ret' (10 clockticks), which costs 27 clockticks. I've
included a file that every TI83 programmer should have by now (ti83asm.inc), but
*this one is optimized*. There are no compatability problems that I know of. One
warning tough: I think it only works on ROM version 1.07000, but it might as
well work for ROM 1.10000 and the TI-83+. I've tested the routines and they save
lots of time indeed. Everything just runs more smoothly than
before.
I don't know if you're able to bring this discovery to other
TI83 users, but it would be nice, because every user could get benefit of it and
all the ASM prog's at ticalc.org should be recompiled. I sincerely do not know
in which category this file should be placed. I think it should be in some
/asm/includes/ directory, but this does not seem to exist @
ticalc.org...
Greetz,
Frank Schoep