TGB1718

I've generally found a really good clean of floppy units will bring them back to life, I know they are a bit fiddly and you have to be really careful not to damage anything while cleaning. Pay particular attention to the heads, I've thought in the past I did a good clean only to find they didn't work, however a second clean did the job.

You are right, L33 is on the Midi out port, it's not on the signal lines, but on a pullup resistor, so unless you plan to use Midi it's all good, personally I think there's no real need for the inductor there, I think a link would be ok.

If you have trouble sourcing one of these, you could solder 3 vertical wires into the circuit board and lay this device on top of the remaining 2 and see if there's enough of the stumps on the device to solder these wires onto, not ideal, but maybe worth a try. Failing that you could put a shorting link across the 2 outer pins (please avoid the centre pin), it should work ok, but you never know how much noise could be on that line (this is the last resort )

Just found a diagram that shows the device, as I suspected it's a double device with an internal capacitor to ground. Sorry for the fuzzy picture, but this is the best I could find. It's connected in series with one of the Floppy Disk lines (they all have one of these), again it's so fuzzy I don't know which line it's connected to. The good news, as long as you can source one I don't suppose it matters which line its on. I got this detail from the 1040ST circuit diagram, so the actual component names may be different, but functionally they are identical.

It's a 1000uH inductor, however it looks like it has 3 terminals so may have 2 inductors internally. The center terminal looks like it's connected to the ground plane, unfortunately I can't find a circuit diagram of this revision board that shows these inductors type.

@phaeron thank you I will take that into account if thing look a bit screwed up EDIT: Spot on, it looked a bit garbled, I added a few NOP's after the WSYNC and it now look really good. 🤩

@thorfdbg thanks you, you gave me the clue as to what I was doing wrong, I was setting the HSCROL register to 0 outside of the DLI, but not inside a VBI, my code was just stuffing 0 into HSCROL while waiting for a key press. Pretty obvious really, but sometimes you just overlook something so simple. Fixed now as the screen shot shows, now I can get on with what I was trying to achieve Thanks to all who helped here

no, I created a "createdl" procedure that makes sure the display list aligns correctly to ensure the 4K boundary is crossed safely. Without the DLI set, the screen looks correct and a small VBI routine can scroll the screen horizontally with no corruption. It only corrupts if I try any horizontal scrolling in a DLI.

Every line has DLI enabled, but I only activate one DLI at line 60 that's why I used VCOUNT, my normal code doesn't use this, I did this just to try to debug/figure out what's going on, so literally I draw stuff on screen enable the DLI with the code shown and I get garbage below that line, doesn't seem to make sense. I expected just to see the lower 1/2 of the screen offset from the top. There's no VBI's yet, I disabled them to make sure there wasn't any conflict. Guess I'll have to dig a bit deeper to see what's going on.

Yes, I am doing it after a WSYNC, the display list is doing an LMS for each line which is 48 bytes wide with DLI and HSCROL enabled, the playfield is standard width A very simple DLI:- .proc DLI pha lda VCOUNT cmp #60 bne xit lda #6 sta WSYNC sta HSCROL xit pla rti .endp

Is it possible to enable horizontal scrolling and change the HSCROL register in a DLI, it appears you can change it once at the top of the display, but anywhere else produces a garbage screen below the DLI change. Here I'm changing the HSCROL register about 1/2 way down the screen and this is the result The program has not crashed, it exits normally on a key press, I'm using the VCOUNT register when it reaches 60, puts a value into the HSCROL register and that's it, DLI's are enabled on all lines, but this line is the only one that activates, this is GRAPHIC Mode 7 (Antic $E) I'm beginning to feel that what I'm trying to do is not possible. dlitest.mp4

How are you doing that, if your setting you meter to current and connecting across the +5 and 0V lines then you are effectively shoring out the power supply, the behaviour your seeing is the power supply protecting itself from the short circuit you have introduced (not a good thing to do). The current rating of a power supply is the maximum is can supply safely, it's not what you will see when measuring current, that will depend on the load presented to the power supply, usually max you would see is about 1/2 or less of the rated value.

The only way to use bank switching in BASIC XE is to use a machine language routine (turn interrupts off) Even then BASIC XE quickly grows up into the memory window so you have to be very careful you don't corrupt the BASIC program itself.

Generally the sort of problem you have suggests a good clean of the mylar and key pads, I've had random key problems on one of my XE's over the years (really need to get a new mylar) and a good clean usually does the trick.

Yes, I'm using MADS and after posting this I found the .align directive which does exactly what you suggest, so not worth the effort of coding something