Questions to the H5 C1 - russellnash

[exxos]

I think you should go back to your reset thread as its getting confusing viewtopic.php?p=114746#p114746 and write on that image all the voltages at each point you get with and without the reset button pushed in.

[russellnash]

Problem solved. I didn't know what to do with the reset circuit so I decided to ignore it and carry on with other things. It was possible to boot by putting a jumper across pins 14 and 18 of the CPU, open=reset, closed=boot. I decided to do the two audio fixes for the volume and floppy drive noise. After doing so it was still very loud and sounded like a Huey landing in one of those Vietnam war films. That seemed strange because I have never seen anyone describe their sound as being so bad. It made me wonder if the YM2149F was to blame.
I replaced the chip and it now boots normally, the reset functions correctly and the sound is normal. A lot of fuss over something that wouldn't have happened if I had chosen another sound chip. :D

[russellnash]

The 16Mhz booster seems to be working fine with TOS 1.04, so the Glue decoding jumper is closed and no wire connection to the CE contact. I tried two different CPUs, the first one wouldn't boot. I started putting everything back together and when I put the Goex drive in, it does not read or write, it just clicks as though it's accessing but the track counter doesn't move on. I also tried an external Gotek as Drive B and it does the same thing. I would swap out the WD 1772 but I haven't got one easily available at the moment. I don't use these drives very often and therefore it isn't that important, but perhaps there is something that I have not done in order to make them work correctly?
The video quality is great, it might be hard to go back to using a normal ST.

[russellnash]

I finally got round to trying another WD 1772, which I could only get by desoldering it from another board. I used my paint stripper heat gun, which went cleanly without lifting any pads or traces. One day I will have to get a proper desolder station. The chip works fine. So, my build would have been trouble free if I hadn't had used firstly a defective sound chip and then a defective floppy controller.