Search found 32 matches

by GozdniJezek
03 Jul 2021 09:17
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

Sorry for asking the obvious, that webpage is so fantastic and holds so much information that is easy to overlook stuff. :) My last question, is there any reason/advantages to pick MAGROM over CFX. Thank you for your help.
by GozdniJezek
30 Jun 2021 17:42
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

Yes I noticed, that waw is not popular anymore. I'll explore the hardware, you suggested, but for starters I believe I'll just go with mp3 player. Is it possible to get preassembled Magrom or CFX or is it all DIY? :) (latest info: Current Stock : 19/06/2020 for MAGROM) Thank you for your help.
by GozdniJezek
24 Jun 2021 15:51
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

victory.png I've also played this wonderful homebrew (I someone has links to other homebrew software I would be very grateful). I've checked the software topic on this forum, the resources on: http://www.primrosebank.net/computers/mtx/mtxsoftware_dl.htm and mtxworld. Does anyone have a compilation ...
by GozdniJezek
24 Jun 2021 15:49
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

Hello, I think I'm due for an update, sorry for such delay, but better late than never. :) To recap what has been done: -One of video RAM chips (4116) was bad and it was replaced -C11 was replaced but had a cold solder joint, symptoms: after a while the computer went into a "reset loop", o...
by GozdniJezek
29 Sep 2020 15:53
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

Hello, time for a new report. :) My friend removed the C11 and measured it with a tester and multimeter and he got: tester: C11 ( 10uF 50V electrolyte) 10.68 uF ESR 1.1 Ohm, Vloss 1.4 Multimeter: 10.03 uF Judging by the measurements this should also be OK. 1.JPG 0.793A measured across the fuse. I th...
by GozdniJezek
22 Sep 2020 18:30
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

Hello, all of the measurements were done with disconnected keyboard. Immediately after turning the machine on the values are: voltage across R16: 0.003 V Pin1 and GND on 9C (4070B): 4.873 V across C11: 4.912 V I presume everything looks as expected and this matches the symptoms (stable picture for c...
by GozdniJezek
19 Sep 2020 09:03
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

Hello, thank you for your support, the reason my posts are so intermittent is that i have the machine at my friends house, that has a formidable laboratory with some very useful tools but I can't visit very often because of the distance. I've kindly asked him for the measurements and this are his fi...
by GozdniJezek
15 Sep 2020 17:39
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

Hello, this weekend I had a new debugging session with my friend, this time a bit more methodical, as poking around did not bring any meaningful results. :) I had a sense to use the oscilloscope before randomly swapping out the oscillator and other components. :D I believe the underlying issue for n...
by GozdniJezek
22 Aug 2020 14:06
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

I've ordered a new crystal as they are cheap and easily obtainable and will try with that first. Secondly I've found a "tester" for the TMS9929: https://8bithardware.wixsite.com/website/product-page/vdp-tms9129nl-tms9929anl-tester . So if the crystal swap won't work this is what I plan on ...
by GozdniJezek
13 Aug 2020 20:30
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 82
Views: 155256

Re: MTX 512 (debugging thread)

Thank you for your replays, I'm still planing on swapping out the VDP crystal, because it's easy and cheap to source. But today I watched an episode of Noel's Retro Lab, where he fixes a SVI 328, that also uses the the same graphics chip TMS9929ANL (VDP) as MTX. https://www.youtube.com/watch?v=KSrMw...