Recent content by 8bitbubsy

Not really sure what causes it, but I'd look for cracked solder joints on the analog board (the one with the white protective plastic board on it). If found, they need resoldering.

Seems like normal SE audio behavior to me (loud audio, loud beeps, slightly quieter on other types of sound). The pops are also 100% normal. It's the voltage to the speaker being turned off, causing a sudden DC discontinuity. Happens after some sounds too. As ymk wrote, you can put a resistor...

Yup and yes. So this poses a challenge then, since the number of output samples per tick is variable when supporting BPM. I still think it should be possible to do it, but it may require more logic in the VBL interrupt. BPM is really important though, so if some performance can be sacrificed to...

So I checked the code, and as expected I couldn't find any BPM handling! I'll try one last time to explain what is missing in this player, which is really important for a huge amount of MODs to play at the correct speed: Most MODs (which means ProTracker MODs) have two values that control how...

Yup, was thinking that one could have a VBL interrupt routine solely used for counting tick samples, ticking the replayer after N samples (for supporting MOD BPM), mixing audio, and transferring the block to the correct location in the hardware audio buffer.

I've been wanting to make an accurate 22.5kHz 16-bit mixing 4-ch MOD player for Motorola 68000 Macs for a long time. I already have an 68000 assembler project for 68k Amigas which loads a module, uses the PT2 replayer code and emulates Paula (Amiga sound chip) to play back modules accurately in...

I see. By the way, shouldn't the actual audio rate be 22254.5454 (recurring) and not 22250.0Hz? Derived from 15667200.0 (pixel clock) / 704 (number of video lines). Not a big error, but 22255Hz would be closer than 22250Hz. Also, vblank is 60.1474201474Hz (15667200.0 / (704 * 370)) and not...

Some things about NanoMacTracker: 1) The clicks and pops most likely come from the fact that there is no volume ramping. Sudden volume changes (and sample triggers) are not interpolated, so they cause an audible discontinuity in the voice output waveform. This is the same on a real Amiga, where...

Sorry for the bump, but DAL is in fact Data Access Language, and has nothing to do with legacy video cameras! Read more about it here: https://en.wikipedia.org/wiki/Data_Access_Language You can probably trash it, yeah.

Awesome! Will this speed-up make sense on a Macintosh SE as well? EDIT: "System 6 includes QuickerGraf (originally QuickerDraw), system software used to accelerate the drawing of color images on the Macintosh II." I guess not.

True, it works fine as is, but if there were to be some speed benefit using either the old or new driver, I'd stick to that one.

Thank you. :)

Should I use the disk driver supplied with System 6.0.7's Apple HD SC Setup on a stock Macintosh SE, or are there any benefits with using the one in Apple HD SC Setup 7.3.5? Also wondering if there are any non-Apple drivers out there that are faster, or otherwise better.

If there's a market for these things, but I kinda doubt it. You need to source a SWIM chip in the first place, and that's not going to be easy. Maybe it would be better to try and replicate the SWIM chip with a microcontroller instead (or an FPGA if needed, but that would be costly).

I see, but I still don't want to design this PCB after all, since I've never designed a PCB before and it's a lot of work. At least I have verified that the PLCC44 SWIM variant will work when rewired to DIP28, so that's something.