Search found 563 matches

by tlr
Sun Feb 18, 2024 1:08 pm
Forum: Programming
Topic: "Free ZP" which ones?
Replies: 6
Views: 243

Re: "Free ZP" which ones?

As written... I am using it in demo so just IRQ Kernel used. 😉 Thanks will look into the other thread. If you are using only IRQ and nothing else then all of zp is free and most of the stack, just be sure to set the stack pointer to a convenient spot. $0314 and $0315 must be set up at the time of I...
by tlr
Mon Sep 18, 2023 8:32 am
Forum: Programming
Topic: Add a machine code routine to a Basic program
Replies: 8
Views: 2282

Re: Add a machine code routine to a Basic program

In its simplest form you can just hook your routine in $0314/$0315 and at the end of your routine just call whatever was in $0314/$0315 before (usually $eabf) to finish up. Without fiddling with the timers this will not be in the vertical blanking but good enough for starting out. You can use the ta...
by tlr
Sun Sep 17, 2023 6:24 am
Forum: Programming
Topic: Add a machine code routine to a Basic program
Replies: 8
Views: 2282

Re: Add a machine code routine to a Basic program

The actual implementation will be different depending on how you partition what BASIC does and what the ML interrupt does. In general the interrupt will pause the BASIC program very briefly (~1 ms) each 20 ms to perform some task you desire. This could be doing the equivalent of X=X-1 & POKE, on...
by tlr
Sun Sep 17, 2023 3:26 am
Forum: Programming
Topic: Add a machine code routine to a Basic program
Replies: 8
Views: 2282

Re: Add a machine code routine to a Basic program

Sure, you can do any mix of BASIC + ML. For smooth movement you'll need to do an interrupt routine to perform that in the background. Typically you'd set up a timer to fire an IRQ once each vertical blanking, and there handle the positioning. If you are doing this from BASIC you should consider maki...
by tlr
Sat Sep 16, 2023 8:31 am
Forum: Programming
Topic: Keyboard Input in Assembly - advice sought
Replies: 14
Views: 2936

Re: Keyboard Input in Assembly - advice sought

I agree with Mike. This looks overly complicated and has all sorts of incorrect assumptions built in to it.

It's seldom a good strategy to code a complete solution and then debug it. Why not start to get a simple two key input working using $FFE4 and then add the cursor + positioning?
by tlr
Mon Feb 13, 2023 2:25 pm
Forum: Hardware and Tech
Topic: 7406 replacement
Replies: 4
Views: 525

Re: 7406 replacement

SN7406 is a 7406 manufactured by Texas Instruments. Should be equivalent. Who manufactured the one that's there now?
by tlr
Sun Feb 05, 2023 3:47 am
Forum: Games
Topic: What would be a good game for...
Replies: 8
Views: 2730

Re: What would be a good game for...

Scramble is my go to.
by tlr
Sat Feb 04, 2023 4:12 pm
Forum: Emulation and Cross Development
Topic: Page boundary crossed, CBM Studio
Replies: 6
Views: 2197

Re: Page boundary crossed, CBM Studio

There is a page crossing, yes. This will make the branches take one additional cycle when taken, but this is normally not an error. Perhaps you have some flag set to the assembler to make this error out?
by tlr
Sat Feb 04, 2023 5:19 am
Forum: Hardware and Tech
Topic: 6560 FPGA Progress.
Replies: 152
Views: 14171

Re: 6560 FPGA Progress.

One technique you should look for is drag soldering/smear soldering. I've never done this myself, but I've seen it done. The general idea is to put solder on by dragging along the pins and relying on capillary action to get the solder to where it is supposed to be. You probably want a decent solder ...
by tlr
Fri Feb 03, 2023 2:47 pm
Forum: Hardware and Tech
Topic: 6560 FPGA Progress.
Replies: 152
Views: 14171

Re: 6560 FPGA Progress.

Well, that's been a hard month. Poor health and a mad rush at work have kept me from the project, but boards and components have been ordered now, so let's see what happens. I've got some 48-pin (I think), 0.5mm pin pitch DIL packages to solder (3 of them), so that'll be interesting - Does anybody ...
by tlr
Sat Jan 07, 2023 4:28 am
Forum: Hardware and Tech
Topic: 6560 FPGA Progress.
Replies: 152
Views: 14171

Re: 6560 FPGA Progress.

I'm still working on this - I'm pulling together a new interface board for a different FPGA (one that money CAN buy), and once I've got that up and running, I'll need to get some child labour in to play games and spot things that aren't right. Nice! Which FPGA are you looking at? Trion T20 is my cu...
by tlr
Sun Jan 01, 2023 11:18 am
Forum: Hardware and Tech
Topic: 6560 FPGA Progress.
Replies: 152
Views: 14171

Re: 6560 FPGA Progress.

JonBrawn wrote: Sat Dec 31, 2022 11:14 pm I'm still working on this - I'm pulling together a new interface board for a different FPGA (one that money CAN buy), and once I've got that up and running, I'll need to get some child labour in to play games and spot things that aren't right.
Nice! Which FPGA are you looking at?
by tlr
Sun Nov 13, 2022 4:28 am
Forum: Hardware and Tech
Topic: 6560 FPGA Progress.
Replies: 152
Views: 14171

Re: 6560 FPGA Progress.

With the reservation that my DAC has the wrong reference voltage (3.3 instead of 5), I believe I've got the sound working identically to how it works in VICE xvic. That sounds good. What I hinted in my earlier post is that in the thread linked Nippur72 seems to still see some discrepancies to HW af...
by tlr
Wed Nov 09, 2022 1:58 pm
Forum: Hardware and Tech
Topic: 6560 FPGA Progress.
Replies: 152
Views: 14171

Re: 6560 FPGA Progress.

VIC-I sound is kind of fiddly, especially the noise channel. Nippur72 did some previous FPGA work on this referenced somewhere here: thread . I seem to remember that there was still some discrepancies to be resolved, but I'm not certain. I've started with the code from the VICE emulator, as that co...