Lee Stewart

It does save 4 bytes where the jump calculation is performed in ENDIF and BACK , and obviates the need for BACK , which saves 18 bytes for a total savings in the resident dictionary of 26 bytes. It also saves 2 trips through the inner interpreter in compiling LOOP +LOOP UNTIL AGAIN because “ , ” replaces BACK (defined as “ HERE - , ”), but time savings while compiling are not usually that important. ...lee

Maybe we should get Fred ( @F.G. Kaal ) to weigh in. I believe he had significant input to later versions of the DSR---maybe even wrote it? ...lee

One of my TODOs is to possibly change BRANCH and 0BRANCH to use absolute addresses (per @Willsy’s TurboForth) instead of an offset (per figFORTH/TI Forth/fbForth), but I really do not see the advantage except, possibly, at compile time, which does not seem that important. The difference at execution time is MOV *IP,IP <---IP is a register versus A *IP,IP <---IP is a register which take exactly the same amount of time, as far as I can tell. So, unless someone (@Willsy? @Tursi? @matthew180? @jedimatt42? @apersson850? @TheBF? ??) can show me a significant difference in execution time, I am inclined to leave sleeping dogs lie—the mod would be significant! ...lee

I added a routine to check for the ISR hook and, if not there, to call the fbForth ERROR word with the proper error message number to print “ISR?” after the usual “ERROR ?” and abort. While adding the new message, I took the opportunity to shorten many of the messages. Now, even after adding the ISR checking routine to bank#0 and the code to call it to 3 words in the same bank, there are 256 bytes free! I should add that the free-space increase is due not only to message size reduction but also to some other changes such as the redefinition of .S and shortening of a handful of words to use newly added words. There is still a little work before release. Here is the current state of the TODO list: fbForth300_TODO.txt ...lee

Regarding booting up fbForth with its ISR disabled, I will have PLAY , STREAM , SAY check for a cleared ISR hook (>83C4) and, upon seeing it cleared, exit the routine immediately. Do you think I should include a message such as, “ISR not active!” or just fail quietly? ...lee

Of course, there can be many reasons for choosing one operation over another. Regarding getting the MSB to the LSB, the point of using “SRL Rn,8” over “SWPB Rn” is usually to zero the MSB in the same instruction—saving instructions can outweigh speed. If you want to duplicate SWPB with a shift, “SRC Rn,8” will do nicely. Furthermore, if you want to test the result, the shift is the only way—SWPB does not affect the status register. Regarding zeroing a register, CLR is, indeed, the clear (groan) winner—unless, for some reason, you need a comparison. Both XOR and LI affect the status register, whereas, CLR does not. LI also takes an additional 2 bytes over the other two, when dealing only with registers. ...lee

With your GPLLNK routine modified to use a writable workspace and storage locations (see @Gary from OPA post above), there are several Scratchpad RAM locations and one ROM location you can store XMLRTN for the return from GPL: >8300, >830E, >831C, >831E in Scratchpad RAM and >603E in ROM. The GROM0 addresses of the corresponding GPL XML instructions to place in the DATA directive at GXMLAD are >0376, >0EDA, >1675, >00E5, and >0131. Some of them have more than one GROM0 location, but I listed the first I found. ...lee

With a couple of changes (“ CELL - ” to “ 2- ” and “ ? ” to “ @ U. ”), the following code is, indeed, shorter—16 bytes less!: : .S ( -- ) CR ." | " S0 @ BEGIN 2- SP@ OVER < WHILE DUP @ U. REPEAT DROP ; ...lee

#1 works, but XX is superfluous. SP! is already defined to clear the stack by storing the contents of S0 in the stack pointer. XX pushes the contents of S0 and SP! wipes it out, i.e., does not use it—so no harm done. Also, .S , though not in figFORTH, is defined in fbForth (from TI Forth) and I like it better because it shows the stack as unsigned numbers. I do like your BEGIN...WHILE...REPEAT instead of the DO...LOOP of fbForth because it looks shorter. #2 certainly works as written and, I must say, I like it a lot. I think, though, that I would define := as : := DUP 1 WORD C@ 1+ + =CELLS DP ! ; to make the string only as long as necessary. Of course, neither form is protected against a second invocation of := for the same string with a length beyond the original. #3 does not work properly for 2 reasons: (1) EXPECT must be executed (last word on the line) before typing the text following it, i.e., nothing happens until <enter> is tapped at the end of the line, so the typed string is ignored while EXPECT awaits input. (2) EXPECT stores 2 nulls after the string is entered. ...lee

Yeah...I remember your tagging me with that moniker when I used this pic as my avatar on this forum: ...lee

To be compatible with current SAMS hardware, the returned LSB should always be ignored when reading the SAMS registers. SAMS hardware merely repeats the page number of the MSB in both bytes, whereas Classic99 does, in fact, return the bank# in the LSB and the page# in the MSB. ...lee

My TI-99/4A journey started in December, 1983, when my first wife bought one for our kids for Christmas after the price drop to $50. I was 40! When TI released TI Forth into the public domain that same month, I was hooked. I first signed on to AtariAge with this post in May of 2011: I’ve been enjoying interacting with this group ever since! ...lee

I know I mentioned this before, but I am thinking seriously of booting up fbForth 3.0 without enabling the fbForth ISR. It is enabled in fbForth 2.0. Besides enabling execution of user ISRs, the only reason to have it enabled is to use the fbForth speech and sound engines. This does not affect the BEEP and HONK words. Of course, you can always do sound lists per the E/A manual, with or without the fbForth ISR. And, you can always re-enable the ISR by jamming the contents of user variable INTLNK into >83C4. The fbForth ISR does not take a lot of time, but it is not nothing. If you don’t need it, it slows the system a touch. Of course, you can always disable it by storing 0 at >83C4. What do you think? ...lee

The next version of FBLOCKS will also allow exiting the old way, but with CTRL+9: Future exits from 64-column editor: FCTN+9: Exit editor to SPLIT2 SPLIT Text window CTRL+9: Exit editor to mode from which editor invoked ...lee

And.... Here is the updated FBLOCKS: FBLOCKS ...lee