Search found 294 matches

by at67
Yesterday, 14:57
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 52
Views: 3044

Re: New vCPU instructions 2.0

Another question: Did you consider opcodes ST2 or STW2 that are the same as ST or STW but with two bytes of address? Note that is little need for the counterparts LD2/LDW2 because the combination LDWI+PEEK/DEEK is only four bytes long and exactly equivalent. There are two 3 slot launchpads availabl...
by at67
Yesterday, 14:28
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 52
Views: 3044

Re: New vCPU instructions 2.0

Update: I've managed to find another 14 instruction slots by re-writing ADDW, SUBW, XORI and BRA, the trick to getting ADDW to work was in moving it to page0 and thus not needing a ld([vPC+1],Y) instruction. I also used a launch pad to move the SYS_Exec_88 implementation out of page0, (to make room...
by at67
12 Apr 2021, 12:34
Forum: Hardware and software hacking
Topic: Sprites
Replies: 4
Views: 494

Re: Sprites

Another update, I have added Bullets; 4x4 user definable patterns that use XOR to draw and restore, (all the usual caveats apply when XOR drawing).
https://www.youtube.com/watch?v=mT-jkaNwsbM
by at67
12 Apr 2021, 11:41
Forum: Hardware and software hacking
Topic: New vCPU instructions 2.0
Replies: 52
Views: 3044

Re: New vCPU instructions 2.0

Reading your page3. It seems that the Bcc instructions no longer need three bytes (e.g. BEQ = 35 3f xx). One can get the same effect without the 35 prefix. Yeah but that would break compatibility unfortunately. Also a question: PEEKX/POKEX do INC or INCW after peeking or poking? PEEKX/DEEKX are 30 ...
by at67
11 Apr 2021, 18:24
Forum: Hardware and software hacking
Topic: Where to find gtBasic emulator
Replies: 13
Views: 418

Re: Where to find gtBasic emulator

Can you get your hands on a CRO? You'll probably need to diagnose the actual CLK waveforms. Another thing I would do is to inspect for physical damage to the PCB and more sensitive components like the diodes using a magnifying glass or digital microscope. An abrupt force from falling is likely to ov...
by at67
11 Apr 2021, 10:45
Forum: Hardware and software hacking
Topic: gtBASIC
Replies: 68
Views: 17783

Re: gtBASIC

Thanks at67, that did it. 8-) If you exit the emulator mid upload to the hardware, then that is a guaranteed way to get BabelFish out of sync with whatever tries to talk to it next. The upload process in the emulator is handled by a separate thread, so it's very easy to exit whilst a long upload is...
by at67
10 Apr 2021, 22:41
Forum: Hardware and software hacking
Topic: gtBASIC
Replies: 68
Views: 17783

Re: gtBASIC

I am trying and failing to use gtemuAT67.exe's "download to HW-Gigatron via right click .gt1 files in its file browser"-function with Pluggy reloaded. First question: Is this a supported function of gtemuAT67.exe v1.0.9R (Windows 10)? Yes it is. If yes: I tried to use Babelfish from Norgates Gihub:...
by at67
10 Apr 2021, 17:52
Forum: Hardware and software hacking
Topic: 10MHz, 12.5MHz and Beyond!
Replies: 29
Views: 14916

Re: 10MHz, 12.5MHz and Beyond!

if i use 74LS logic what crystal should i use - 8mhz? Most people who have overclocked with LS/HCT have gotten to around 8~9MHz. if i use 74HCT can or should it be 10mhz? Not sure you can get to 10MHz on HCT without some other changes to the clock circuit and possibly the diode decoding matrix, (th...
by at67
10 Apr 2021, 17:20
Forum: Hardware and software hacking
Topic: Where to find gtBasic emulator
Replies: 13
Views: 418

Re: Where to find gtBasic emulator

Yeah ! it speed up ! How can I compile my gtBasic code ? Is it commande line ? You can compile from the command-line, there is a at67/tools/gtbasic/gtbasic.exe command or you can press CTRL + B and navigate, (left click on folders), to your *.gbas source code and then left click on the source code ...