Willsy

Discussion about what to call a TI-99/4A with F18A: Simple: freaking awesome. You're welcome. No charge. :-)

Hey Tursi, thanks for the kind words about TF and fbForth !

I can look at it at the weekend if you want. Speech is (for me) by far the most interesting feature of the 4A.

Talking all things '99. Fire up your podcast players!

Totally. I have never tried it for exactly that reason. Yes I think that's true. Assembly first then Forth. Assembly on the 9900 family is the nicest I've ever used. 68k coming a close second place.

So in terms of speed versus programming effort it's clear: we should all be using C since that's is very close to assembly language speed but much easier to write the code in C than it is in Forth or assembly. Hats of to the GCC compiler for the 9900. Seriously impressive.

I check the hardware collision bit first. If not set then there's no collision. If set then subtract the coordinates of the sprites in question from each other and take their absolute value. If less than a tolerance that you specify (eg get 4 pixels) then there's a collision. That's how I do it. FWIW.

That's not the seed. That's the limit. Learn the difference between a limit and a seed.

Wow that's really good!

Ah. I see. Yes I think that's fair and I see what Sometimes was saying now.

Well not really. I was just seeing if I could improve tursi's time of 48 seconds.

Ha ha yes!

This one is based on Tursi's code, but pokes VDP directly. Some other little optimisations: VARIABLE cnt hex : asterisk DATA 4 0028 107C 1028 0000 12a dchar ; decimal : test 1 gmode page 1 magnify asterisk 0 0 0 42 1 sprite 100 cnt ! begin cnt @ 0> while 239 0 do i $301 v! loop 175 0 do i $300 v! loop 0 239 do i $301 v! -1 +loop 0 175 do i $300 v! -1 +loop -1 cnt +! repeat bye ; and here's one that removes the need for a variable: hex : asterisk DATA 4 0028 107C 1028 0000 12a dchar ; decimal : test 1 gmode page 1 magnify asterisk 0 0 0 42 1 sprite 100 0 do 239 0 do i $301 v! loop 175 0 do i $300 v! loop 0 239 do i $301 v! -1 +loop 0 175 do i $300 v! -1 +loop loop bye ; Both of them take 29 seconds. So that's 3.6 times slower than assembler and 69 times faster than XB. Rock on!

Yes of course!

Hmm.... it's academic but you might be able to make TF go faster by making it more like the assembly version. I.e use V! To poke VDP memory. I'll have a look this evening and see if it'll be any faster. I was disappointed when I saw 48 seconds, but on the other hand SPRLOC and friends actually update a copy of the sprite attribute list in cpu ram and copy portions of it to VDP so there's a lot going on under the covers.

Not quite. You can freely mix Forth code, variables, buffers, and assembly language in TF in both high and low memory just by changing the variable H. See H and FFAILM and FFAIHM. But I'm splitting hairs; I take your point that you do have access to more memory in GPL.

Cool. Will have a play tonight.

Wow thanks for posting that! It's been 25 years since I saw that!

Yes. I think auto motion would work. I was young and not very experienced. It was my first assembly project on the 4A. I whince at the code: using MPY to multiply by 32. Oh dear! I always did my assembly code with a pen then tried it out. Rinse and repeat until it worked. Even now I tend to work things out away from the computer!

Some notes: TGWTK NOTES.TXT A disassembly: TK2.txt I wrote that in 1991 - 25 years ago!! The original source code is long gone, as it was written in a small notebook in pen, and typed into the Line-By-Line assembler by hand!

Here you go, 'yall... TGWTK.zip The attached is Win994A disk image, of course you'll need to insert the mini-mem cart into Win994A. If you rename the file extension from TIDISK to DSK you can open the disk image in TIDIR or Michael's TIImageTool and export into FIAD or any other format. Here's the manual, just for kicks:

If anyone has it I'd be grateful. Preferably with the formatter program included. Got some old text that I want to get out of TI Land into PC land. Alternatively, the TI Writer Cart binaries and the TI Writer Disks. Thanks Mark

If a 4A is fitted with an MBX expansion box thus giving it speech recognition facilities, is it still a 4A? :-)

Can GPL access any area of CPU ram or can it only access PAD ram?

I think it's slower than TF because a lot of TF words are implemented in machine code. A good test would be to write something like a screen scrolling routine like the one TF had in GPL and test it. I think it will be quite a bit slower. Also, compared to Forth, you can't just type something in and test it. You have to assemble it and make a cart image. Laborious and time consuming but a lot easier with cross compilers than the old days! Finally, for deployment you can't use a simple ROM cart, you need a GROM capable cart. So on the face of it I don't think there are any good reasons to use it, other than its really cool! If I was writing TF now I'd actually put a GROM in it to do the cart header and all the initialization before TF starts up (character sets and all that good stuff). Would have saved around 2k of ROM space. There's a lot of code you can squeeze into 2k. :-)