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Troubleshooting ADI F4DXP-UC5D-I

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First post, by weedeewee

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Troubleshooting ADI F4DXP-UC5D-I

I recently obtained this board https://theretroweb.com/motherboards/s/adi-f4dxp-uc5d-i
2 capacitors near the cpu socket were bent and got replaced.

Attached a hard drive with some tools & a windows 98se install and all worked quite well, no odd crashes whatsoever.
It just doesn't want to read or write a floppy, which I figured out after wanting to install the ide driver for windows.

Did some reading, mostly this thread and a few of its references, How to fix your dead on-board floppy controller .
Two people fixed it by replacing the um8663 chip, one didn't have so much luck, feipoa, amigasith & synoptic .

I could order another um8663, though I'm not convinced that is my problem.
Reason I think this is because I attached a scope to a few lines, nl DRQ2 DACK2, and I see the DRQ2 being asserted, yet there is no response on DACK2.
DACK2 is still connected to all the relevant chips (I think all), the isa slots, um8886 and um8663
This leads me to believe that the culprit might be the um8886, which is be a bit more annoying to find & replace.

Which leads to the scrambled audio.
if the floppy dma wasn't working, I needed a way to check the dma functionality and what best way to do it than a simple audio card.
(an sb awe 64 in my case. easy enough to get sound out of it using the diagnose software, which btw, does install if you just rename the windows directory)
well, the audio output does work, though both 8 & 16bit dma give scrambled audio, like you can hear the original sample but it has a lot of static noise.

I've tried both setup&bios default settings, the slowest possible settings I could set in the bios & on the mainboard,
and the noise is worse with the slower settings, as in the diagnose sample becomes barely identifiable.
though setting everything to fastest possible, without going over, doesn't make it better.

I've been tracing the pins and got stuck at the following list

um8663 pinout 
um8663af
pin
100		
99		
98		DACK2
97		T/C
96		A10
95		
94		
93		
92		
91		
90		IO CH RDY
89		
88		
87		
86		
85		GND
84		2	density
83		10	motor enable a
82		12	drive sel b
81		14	drive sel a
80		16	motor enable b
79		18	direction
78		20	step
77		22	write data
76		GND
75		24	write enable
74		32	head select
73		8	index
72		26	track 0
71		28	write protect
70		30	read data
69		34	disk change
68		UM8667(9)
67		UM8667(10)
66		UM8667(11)
65		UM8667(12)
64		UM8667(13)
63		UM8667(14)
62		UM8667(15)
61		UM8667(16)
60		
59		UM8667(17)
58		UM8667(18)
57		UM8667(19)
56		UM8667(20)
55		UM8667(21)
54		
53		UM8667(22)
52		UM8667(23)
51		UM8667(24)
50		
49		
48		
47		
46		GND
45		
44		
43
…Show last 43 lines
42		
41		
40		DRQ 
39		
38		
37		GND
36		
35		
34		
33		
32		
31		RESET
30
29		D7
28		D6
27		D5
26		D4
25		GND
24		D3
23		D2
22		D1
21		D0
20		AEN
19		DRQ2
18		IOR
17		IOW
16		IRQ7
15		IRQ6
14		IRQ4
13		IRQ3
12		DACK
11		A9
10		A8
9		A7
8		A6
7		A5
6		A4
5		A3
4		A2
3		A1
2		A0
1

My main annoyance with this list is not having a clear connection to any voltage line.
I would expect it to be connected directly to +5v but haven't gotten any continuity beep on it.
Also not finding the isa ALE line.

um8667 pinout 
48		com1
47		com1
46		com1
45		com1
44		com1
43		com1
42		-12V
41		com1
40		com1
39		com2
38		com2
37		com2
36		com2
35		com2
34		com2
33		com2
32		com2
31		
30		12V
29		UM8886AF(158)
28		UM8886AF(157)
27		
26		
25		
24		UM8663AF(51)
23		UM8663AF(52)
22		UM8663AF(53)
21		UM8663AF(55)
20		UM8663AF(56)
19		GND
18		UM8663AF(57)
17		UM8663AF(58)
16		UM8663AF(59)
15		UM8663AF(61)
14		UM8663AF(62)
13		UM8663AF(63)
12		UM8663AF(64)
11		UM8663AF(65)
10		UM8663AF(66)
9		UM8663AF(67)
8		UM8663AF(68)
7		+5V
6		
5		
4		game(7) joyAbtn1
3		2k2 - game(6) joyAy
2		2k2 - game(3) joyAx
1		game(2) joyAbtn2
a few of the um8886 pins 
um8886af

152	IRQ6

147	DACK2
145 DACK1
144	DACK3

56	KBD CLK
55	KBD DATA

23	DRQ7
22	DRQ6
21	DRQ5
20	DRQ3
19	DRQ2
18	DRQ1
17	DRQ0
16	DACK7
15	DACK6
14	DACK5
13 	DACK0

any ideas anyone?
any points to probe ?
further avenues for exploration aside from just replacing chips?

ps. I've noticed from the available photos on the other thread that the pinouts can differ, mostly seen on the um8667.
and if anyone can add more pins to the list, please do.
and i'll add some photos later, so they can be added to the retroweb site.

Right to repair is fundamental. You own it, you're allowed to fix it.
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Do not ask Why !
https://www.vogonswiki.com/index.php/Serial_port

Reply 1 of 5, by weedeewee

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a little followup

while I was getting dma overflow errors in fdformat or imagedisk (can't recall which one). Now I'm no longer getting these errors and the dack2 signal is responding properly.

also forgot to mention that I tried previously with a seperate io controller with everything disabled except the FDCand that also didn't work
at the moment it's trying to do a format of a floppy but with the audible retries it's likely still going to fail, so something is still not working correctly.
That and the digital audio is still borked.

edit: amazingly, beyond my expectations, the format finished, (with all the retries, and an abort retry fail before ending) and the disk is actually readable.
at the moment, I'm flipping the table in my mind, since it hasn't been working for several days, and while there's definitely still something wrong, i'm amazed at the current behaviour.
only thing I did today was lift pin 20 on the um8663, and then putting it back, since I actually wanted to lift ale, though no idea where that is.

edit2: using fdformat and the floppy is usable, system transfered, bootable.

on a side note, I measured the voltage with which the NiCd battery is being charged and it's 4.15v. (no idea what current, yet)
after leaving the board resting for a day the voltage on the battery still reads as 3.9v
Yes, I think this is still the original battery the board came with, and no, i'm not going to cut it off since it's not leaking.

edit3: after letting it cool down & starting back up again, ie, turning it off & then on again. the dirlisting is incorrect. something is corrupting data
until it warms up and then it's back to working again. the problem went from being constant, to one part intermittent and one part still constant. urgh.

edit4: 19:09 Haven't resoldered any pins yet. Only got more confused. Getting dma corruption in dos, but not in windows. floppy and digital audio now function in windows, yet not in dos.

edit5: 20:54 just found the pinout for the um8886n in this comment Re: UMC8881/8886 Datasheet
doesn't seem to match up completely, especially the keyboard. and connection to um8667 seems odd, though I likely counted wrongly, the distance between'm is still off.

next step, running the soldering iron over all the pins together with some flux & trying to figure out why the audio is still scrambled.

Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !
https://www.vogonswiki.com/index.php/Serial_port

Reply 2 of 5, by weedeewee

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feipoa wrote on 2016-08-04, 10:16:
Synoptic wrote on 2016-08-08, 14:53:
amigasith wrote on 2021-05-13, 22:11:

Did any of you experience digital audio issues during your floppy issues?
and did those issues seem to disappear in windows when the system got warm yet remained in dos.

I just tried a cold cold boot and there was distortion audible in windows, though hardly as much as in dos
In dos it's constant, like listening to a detuned radio, while in windows it's just an occasional pop & crack.

Just tested copying from floppy in windows after a cold cold boot and it sounds normal. i'll have to check if there's any data corruption, but all the headsteps sounded to be there.
This doesn't happen in dos after a cold cold boot, if it wants to read, it sometimes does a step when going to another file.

Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !
https://www.vogonswiki.com/index.php/Serial_port

Reply 3 of 5, by weedeewee

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Welp,

What can cause dma to fail in dos, yet work in windows ? Default dos & windows, no specific drivers installed.

anyone ?

Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !
https://www.vogonswiki.com/index.php/Serial_port

Reply 4 of 5, by amigasith

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weedeewee wrote on 2022-11-15, 10:09:

Did any of you experience digital audio issues during your floppy issues?

Sorry, but I can't really comment on this. When I fixed my floppy issues, there was no sound card plugged into the mainboard, so I didn't pay attention to any potential sound issues.

Reply 5 of 5, by weedeewee

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amigasith wrote on 2022-11-24, 21:08:
weedeewee wrote on 2022-11-15, 10:09:

Did any of you experience digital audio issues during your floppy issues?

Sorry, but I can't really comment on this. When I fixed my floppy issues, there was no sound card plugged into the mainboard, so I didn't pay attention to any potential sound issues.

Thanks, it's not really sound card specific.
I just noticed the floppy not working first, then tested with a sound card, and now am stuck on the, to me at the moment, incomprehensible occurrence of sound & floppy working in windows but not in dos.

Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !
https://www.vogonswiki.com/index.php/Serial_port

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