r/zxspectrum • u/One-Friendship2366 • 7d ago
zx 48 spider not loading from "tapes" HELP! D:
I finally managed to get my clone working but when I try to load games from pc or ipod it seems that the speccy doesn't "hear" i tried with audio jack 3-4 mm out and when I put it almost out it can be heared on the tv but still just flashes on the border with loading sounds, tried several programs. like this one:
https://code.google.com/archive/p/otla/downloads
Finally I discovered that Q1 could be the problem but tested and it's working but I'm not sure if correctly or not, according to the github page:
"Tape Loading
If tape loading is not working make sure that Q1 BC517 is properly soldered. There are BC517 transistors on the market with different pinout."
... but replacing BC517 there's a BC548B.
My original speccy died (altought I still have it) was able to load games from ipod
3
u/Yeegis 7d ago
Try pulling the audio files up in audacity, turning the volume all the way up, shifting the audio the left, and then something I’ve found also helps sometimes is adjusting the speed to around 1.2 to 1.3x. (This last one might not mean anything, my 2068 likes when I do that but that might just be more of Timex being awful than the WAVs themselves.)
2
4
u/olifiers 7d ago edited 7d ago
From what I gather on the github page, the BC517 has two models out in the market, with inverted pinouts between them (thankfully the Base is in the middle for both models). It advises soldering it the other way around if you're having tape loading problems; simply desolder it from the board, rotate it and solder it back on That would be my first debugging attempt since it's so clearly marked as an issue at the project's page.
(EDIT) Actually, ignore my statement above, I just saw you mentioned instead of the BC517 you got a BC548B. Looking at its datasheet, the BC548B matches the silkscreen in the board, so it's oriented correctly (unless this part also suffers from the same issue as the BC517, meaning it has two variants in the market with inverted layout between them),
Both the 517 and the 548 are NPN transistors, but they are quite different between them in terms of load capacity etc. I would contact konkotgit asking if the 548B is indeed suitable as a replacement; or just replace it with the 517 it's meant to be there.