@fuzzweed.co.uk Aha. Now you’re talking!
@fuzzweed.co.uk I’ve not really looked into it, but the PlusD/DISCiple interfaces page themselves in on the interrupt. (Not sure of the exact trigger). So it still fires at 50Hz but they’re able to use a custom handler by paging in their own ROM to service it. Maybe you could mod your MIDI board to do the same??
@fuzzweed.co.uk The interrupt routine just calls the keyboard routine, and increments the FRAMES counter. You could do those in your routine instead if you want. Keyboard routine is CALL $02BF if you want to call it directly.
(You could just do an RST $31 but that will also re-enable interrupts with an EI).
@fuzzweed.co.uk I think that’s what IM2 is meant to do. The device identifies itself on the bus, and the programmer sets up their handler at the appropriate vector. The usual 257 byte table is just a Speccy hack to be able to use IM2 at all. Each vector could be a separate device handler.
@fuzzweed.co.uk More here, but the answer seems to be “not much”!
spectrumcomputing.co.uk/forums/viewt...
@fuzzweed.co.uk The only one I’ve heard of that might is the AMX mouse.
@fuzzweed.co.uk You know what they say; when in doubt chuck some raw byte values at the display file!
My $dayjob is 99% just doing console.log() and my hobby mainly consists of LD (0x4000),A
@fuzzweed.co.uk 🚨 🔊 🙌
@fuzzweed.co.uk Heh, you migt like this then. I found it while digging through some Spectrum deep lore on Usenet the other week.
@sonicyoda.bsky.social I first discovered Mahjong on a Spectrum cover tape and it might well be one of mine
@samcoupe.com How did it go? Are you there again today?
@doginatank.bsky.social Brings a whole new meaning to "double jewels". Lets hope the sprocket holes will be positioned just-so to save our blushes.
@der-kleine-drache.bsky.social I think for MFM the flux transitions are continuous around the track, but there are “gap bytes” and “sync bytes” that are there to allow for timing variations among different drives.
@markfixesstuff.com Aye, and paging 32K chunks feels awkward, but u get used to it! External RAM is not contended, that’s quite interesting, internal depends on the screen mode. “Speccy” Mode 1 is slowest, full colour mode 4 is still a lot of data to move around. Mode 2 (similar to Next Layer 1,3) is a good compromise.
@der-kleine-drache.bsky.social Ah, no I don’t think so. Come to think of it I usually just export it to eDSK image and let the emulator figure it out! You could probably make a guess based on sectors per track though? 9 for ST and PC, 10 for CPM or general Shugart systems, 11 for Amiga (22 for HD disks), etc etc.
@c64reloaded.bsky.social Well, actually…! It can be done on +3/+2A (see part 6). Just not in exactly the same way.
@der-kleine-drache.bsky.social HxC Floppy software is good at decoding the raw flux data and exporting to a suitable image format. (And those disk visualisations!) I tend to use samdisk though, which works with the (SAM, Spectrum) formats I generally need. I think there are GUI greaseweazle tools too?
@markfixesstuff.com It’s such a charming system to work with. Its compatibility with the Spectrum was perhaps overstated but you can see the DNA running through. If you used Beta BASIC and a DISCiPLE or Plus D then you can see that SAM is a refinement of Andy and Bruce’s work.
@fuzzweed.co.uk Tis the season! 🥚🍫
@fuzzweed.co.uk If you’re not also using half an Easter egg as the bowl I don’t even want to hear about it. 🍫 🍫 🍫 🍫 🍫 😅
@mattround.com In Scots it has a slightly different / more specific meaning: flirting, “going out on the pull” etc. My gran would use the word but it‘s been a very long time since she accused me of “gallivanting wi lassies” so I've not really heard it for a while! But a good word in both senses I reckon.
@jamhamster.bsky.social A cool thing you can do with it is drive two displays at the same time (one shows the normal screen while the other shows the shadow screen). Have you tried it?
spectrumcomputing.co.uk/entry/39482/...
@fuzzweed.co.uk Haha, snap!
@fuzzweed.co.uk Ah, cool. I think if you ALIGN the table you could get away without DE etc and effectively “add a to hl” by doing LD L,A
@fuzzweed.co.uk Ah, I’ve never programmed the SID, is that 7 for each voice and 3 for filter? Could you use a lookup table instead of doing x7 ?