Denial

;--- wait until the first raster line until starting timer soc_lp3: lda $9004 bne soc_lp3 This code has a race condition in that, if it happens to start in any cycle during the two first raster lines the timing will be misaligned. The first loop I have will ensure we are not on any of the first two...

Here's my take on the problem, using a single timer this time: vicrast.prg The idea is that as you can load the T1 latches through $9126/$9127, I just preload those on each interrupt and then automatically get cycle exact reload of the timer. Then it's just a matter of making the sum of the splits e...

vicassembly wrote: ↑Tue Jun 16, 2020 4:01 pmI just cannot wrap my brain around this.

Of course you can. Admittedly it's a bit fiddly and requires certain insights about the hardware but it's not total rocket science.

What is it that is confusing you? I'll try to answer.

chysn wrote: ↑Fri Jun 12, 2020 6:51 amWhat's with the backwards text?

That's a common loop size optimization. You could also use a "negative" index value and count up to $00, but then the base address needs to be adjusted to point to the right location (also usually generates a page crossing = +1 cycle).

For arbitrary data I guess it's not possible to undercut that strategy. Assuming there are sequences in the data, like runs of equal symbols or simple patterns, then you can potentially generate the output faster. Finding the patterns could be automated, as in coding a specialized cruncher.

This is what I've used as reference when doing C16 tape masters: comp.emulators.cbm: How did the Cbm64/vic20 tapes work technically ------------------------------------------------------------------ From: Markus Brenner 2001-01-23 arcade...@hotmail.com wrote: >I want to write a utility that takes th...

For my real job, I've used Eclipse for years. I get some gentle ribbing from my staff about this. It's apparently an old developer's IDE. Guilty as charged, I guess. I like Eclipse a lot, but not for 6502 projects. Old developers? To me, eclipse is something fairly newskool. :wink: Same editor I've...

Its just an R2R ladder, really trivial :) This one was kinda common at some point: https://en.wikipedia.org/wiki/Covox_Speech_Thing (there was a userport variant too). I'd go for 8bit mono instead of 4bit stereo, as more bits greatly improve the quality The one in Noizer's post seems a bit strange ...

funkheld wrote: ↑Tue Dec 10, 2019 11:09 amWho can explain that to me, please?
BYTE $0B, $10, $0A, $00, $9E, $34, $31, $30, $39, $00, $00, $00

That's tokenized BASIC for "10 SYS4109".

Name: cbmtools 0.8 Author: tlr Released: 1 November 2019 Requirements: Cross-platform cbmtools is a collection of tools operating on cbm-style prg-files: chd - cbm binary hexdump cld - cbm binary linker (opt executable output) csiz - cbm binary range checker cdis - cbm binary disassembler cdif - cb...

Yeah, I'd be looking for something like this: https://www2.hdl.co.jp/en/plcc68-series/ap68-01-m.html That must be one of those adapter boards you refer to (which would be fine)... but of course then I'd need to get one containing my chip.. or would I? Having said that.. maybe I won't actually need ...

On a slightly different note -is anybody here familiar with FGPA/CPLD devices? I'm just aware that FGPA/CPLD dev boards usually have the chip soldered directly onto the board (e.g. Altera Max II EPM240) Can you buy "programming" boards with sockets on them.. and preferably variants of the...

I've read that the older 6502's don't like running at slow speeds. I do have a few of the the modern ones so that shouldn't be a problem. Do you think all of the other chips would be happy running ridiculously slow at something silly like 2Hz? Won't the Vic have old RAM chips that need constant ref...

Isn't nippur72 working on something like this?

The actual VIC-I logic should be fairly straight forward. Making it into an actual chip substitute requires some fiddling to get the I/O right with regards to timing + the analog video and to some extent audio stuff.

Good job keeping everything running with minimal interruptions!

It seems that http://sleepingelephant.com/denial/ (without the www) still redirects to the temporary domain. I'm guessing that it is on the server side but I'm not sure how much magic my browser has cached.