exxos's Atari, Amiga & retro forum

exxos wrote: 05 Mar 2021 23:04 Did you program the GAL yourself ? Either its not programmed correctly, or faulty GAL by the sounds of it.

Well, definitely is not programmed, because I did not know that it needed to... And also don't know how to. :-)

Any instructions around?

You need a gal programmer ... Then read the manual on how to use it...

exxos wrote: 06 Mar 2021 02:09 You need a gal programmer ... Then read the manual on how to use it...

OK, I found out that the TL866+ I have can program GAL (in particular the 22V10D). And using minipro on Linux, I can detect it:
I just found this article: https://www.exxosforum.co.uk/forum/viewt ... ing#p33807

So: @exxos or @Icky, could I have the code to program the GAL, please? :-D

@AndresPlazaR - have PM'ed you.

Icky wrote: 06 Mar 2021 06:27 @AndresPlazaR - have PM'ed you.

Thank you very much!

So, after programming the GAL (thanks @exxos, @Icky and @kodak80), pin 14 in the GAL does output 8MHz:
But, floppy in 720k mode did not work.

Then, I connected pin 2 of the Gotek to the bottom pin of JP18 (as suggested in https://www.exxosforum.co.uk/forum/viewt ... ing#p33807 ), but also did not work.

(with "did not work", in all cases, I mean the drive does not make seek sounds and, when trying to open the drive in TOS 2.06, I get the message "Data on the disk in drive A: may be damaged.")

I just wanted to verify something: @kodak80, reading your post mentioned above, in the section about automating the selection of 720 or 1.44 modes, it says:

JP22 has pins 2 and 3 connected so that the 1.44mb IC controls the clock speed to the WD1772.

Are the pins in JP22 different in the H4 board than the H5? Because in the label of the H5 B1 board, it says pins 2&3 are for "8MHz 1772" and 1&2 are for "8MHz & 16 MHz GAL mode". So, it seems to be opposite of what's described in the post, right?

In any case, I tried JP22 in both 1&2 and 2&3, and the Gotek still does not work.

Jp22 if you check has 8mhz on one side, so that and the middle pin simply feeds 8mhz to the 1772... So the GAL does nothing... If its not working with 720k, then you have some other problem...

BTW I cannot remember offhand if the 1k series resistors were swapped to 500R on the B1 or not.. So might be worth checking...

exxos wrote: 06 Mar 2021 19:31 BTW I cannot remember offhand if the 1k series resistors were swapped to 500R on the B1 or not.. So might be worth checking...

I just measured RN1, RN2, RN15, RN16 and RN17 in the H5 B1, and they are 1 kOhm.

I will keep looking, and report back if I find anything.

If anyone has ideas, let me know. :-)

2 single resistors next to the 1772...

exxos wrote: 06 Mar 2021 21:10 2 single resistors next to the 1772...

Oh!

R21 and R22 measure 470 Ohms (and, at least in the schematics I have for the H5A, they are spec as 470 Ohms).