Hm I made a mistake in saying they are local labels. They are multi labels, meaning they can be declared more than once, which is handy for something like "!msg" or "!loop". But you would have to specify the next or the previous label using "-" or "+". So they are not truly local in that sense (you ...

Kick assembler supports local labels as well as scopes. It's very powerful.

(As a side note, I found its segments feature to be useful for building cartridges)


lda #42
sta routine1.xx
jsr routine1
jsr routine2
jsr routine3
jmp *

routine1: {
lda xx
beq !dostuff+
sta yy
!dostuff:
lda ...

Edit(Moved to top as it is my prime suspect issue) If your LED setup is causing you trouble I would double check the port constants so that you haven't mixed up DDR or PORT etc. For example, mixing up DDR and PORT would make the LED flash if you have set your output to 1 and toggle the DDR pin, but ...

I have been using standard machine drilled DIP-8 sockets for my oscillators so far, by cutting off the non-corner legs. I have recently noticed however, the oscillator on my SBC is wiggling a bit in the socket. I do have some occasional stability issues, so I have started to wonder if perhaps that ...

Well I did some wiggletesting and the instability issues definitely seems to be related to the socket. (The cpu immediately crashes when I shift the position - although I have not confirmed it is a specific position that is the working position). Perhaps I should just solder the oscillator directly ...

I might have mixed up the terminology, but I use the ones with round holes that usually hug normal ICs pretty well. I can add that it is a random brand name (i.e. local supplier, labeled just "DIP-8 socket")

The stability issues might not be related, I haven't investigated that much as it happens ...

I have been using standard machine drilled DIP-8 sockets for my oscillators so far, by cutting off the non-corner legs. I have recently noticed however, the oscillator on my SBC is wiggling a bit in the socket. I do have some occasional stability issues, so I have started to wonder if perhaps that ...

For a classic "parallel" sprite engine, I think it is just a matter of scaling up the hardware for as many sprites you support on a scanline at the same time. My guess is the PPU used the raster time available to read from memory the sprite metadata (bitmappointer, X, Y, flip, palette etc) , storing ...

Johan, you're using 2 bits for 3 "colors", you could make it 4 "colors" with zero additional cost by using XOR instead of OR to compose your image after the AND mask:


AND XOR Effect
0 0 Off
0 1 On
1 0 Transparent
1 1 Inverted


With the normal inclusive OR, the fourth combination is just a ...

Yeah, I do need to learn programmable logic at some point, I'm thinking of picking up a handful of PALs or something in my next order to mess around with them and figure out how they work. A lot of the circuits I'd need for this sprite hardware also fall into the category of "technically doable ...

Fwiw, there is always software sprites as a backup. I created a software renderer in my emulator (since I don't have the actual graphics hardware yet) for a memory mapped 256x240px tilebased 1-bit graphics display and with massive loop unrolling got about <1800 cycles for a free moving 8x16 sprite ...

Wonderful, this is what I was after! And FWIW the Attiny isn't that complicated, sure you will have to write code for it, but I am a programmer at heart so that is not a huge problem. If anything I think it slightly reduces board complexity (putting debouncing and toggling into one chip).

Well currently I am just powering my SBC off the FTDI-cable, or using an Apple Charger through the USB-port, as I have very few components on the SBC. My next design involves dual port RAM (either a 7134 or a 7007, haven't decided if i should go small or big yet, a few 100 mA according to the spec ...

I don't know the details of ATX PSUs but can't you just connect PWR_ON# to ground through a toggle switch, and pull it up to +5VSB through a large resistor?

Absolutely possible. But since the power button on a modern case is not a toggle one, but that other kind that is in "active" state only ...

Hi!

I am in the making of a rev 2 of my 65C02 SBC with onboard graphics and all kinds of peripherals. It's a lot to get working so I am trying to verify all new parts separately. One of the improvements I'd like to make is to have the board on a mini-ITX form factor and mount it in a case. For the ...