exxos's Atari, Amiga & retro forum

Hi all,

Thanks to our brave Atari Area forum colleague GWINTER, who made his card available for analysis, it became possible to read all five GAL20V8 protected chips. I would like to point out that the card is in full version and supports both Mono and Color. So it is possible both to repair damaged cards and to upgrade existing Mono with a Color version.

For files, please visit my www

Greetz

tOri

Well done !

I test it ...

When I change only GAL IV I can select the Color Option C-27 but the driver bombs with two bombs. I test also II and III

@ tOriman

a question ...

They're all 20V8 GALs, aren't they?

Some JED are 1k and the others are 2k...?

Hi frank.lucas,

Try to change other three, without GAL_V.
I am sure that all the chips were read correctly.
Maybe driver has a problem?

Greetz
tOri

edit:

yes - all are GAL20V8. I was surprised - why GAL_I and GAL_IV are shorter but it seems that simply some lines aren't used.

I had change GAL II, III and IV

continue with exchange from GAL I but the sticker matches with "MD41V11" ...

Hi,

I checked all chips again and it looks like all were read good.

Greetz
tOri

edit:

I checked datasheet and it looks like pins 22, 21, 20 of GAL_I aren't used or are used only as Feedback pins, pins 22, 21, 20, 19, 18 aren't used or used only as Feedback pins for GAL_IV therefore JEDs are that short for GAL_I and GAL_IV.

edit2: I used jed2eqn on GAL_I and GAL_IV Below results:

chip gal_i GAL20V8

CLK=1 i2=2 i3=3 i4=4 i5=5 i6=6 i7=7 i8=8 i9=9 i10=10 i11=11 GND=12
/OE=13 i14=14 o15=15 ro16=16 ro17=17 ro18=18 ro19=19 o20=20 o21=21
o22=22 i23=23 VCC=24

@ues 0000000000000000
@ptd unused

equations

/o22 = gnd
o22.oe = gnd
/o21 = gnd
o21.oe = gnd
/o20 = gnd
o20.oe = gnd
ro19 := /i5 * /i6
ro19.oe = OE
/ro18 := /i23 * i7 * /i8 * i9 * i10 * /i11 * i14
+ i23 * /i7 * /i8 * i9 * /i10 * /i11 * i14
ro18.oe = OE
/ro17 := /i5 * i6
ro17.oe = OE
/ro16 := /i4
ro16.oe = OE
o15 = i2 * /i3 * /i4
o15.oe = vcc

chip gal_Iv GAL20V8

i1=1 i2=2 i3=3 i4=4 i5=5 i6=6 i7=7 i8=8 i9=9 i10=10 i11=11 GND=12
/i13=13 i14=14 o15=15 o16=16 o17=17 f18=18 f19=19 f20=20 f21=21
o22=22 i23=23 VCC=24

@ues 0000000000000000
@ptd unused

equations

/o22 = gnd
o22.oe = gnd
/f21 = gnd
f21.oe = gnd
/f20 = gnd
f20.oe = gnd
/f19 = gnd
f19.oe = gnd
/f18 = gnd
f18.oe = gnd
/o17 = i2 * /i1 * i3 * i23 * i4 * f21 * i5 * /f20 * i6 * f19 * i7 * /f18
* i8 * i9 * /i10 * /i14 * i11 * i13
o17.oe = vcc
o16 = i2 * i3 * i23 * /i4 * f21 * /i5 * /f20 * /i6 * /i7 * /f18
o16.oe = vcc
/o15 = i2 * /i1 * i3 * i23 * i4 * f21 * i5 * /f20 * i6 * f19 * i7 * /f18
* i8 * i9 * /i10 * /i14 * /i11 * i13
o15.oe = vcc

And for sure there are many unused outputs and many used feedbacks...

tOri

edit3: GAL_IV is Lattice's GAL20V8A but that shouldn't matter AFAIK different groups behaves same...

I swapped the four gals 1 to 4. If I swap the IV GAL alone, I get the color c27 option in the selection.


It loads the matrix bios first, then comes the selection and then amc gdos starts up and then two bombs comes and there is a reset. With matmouse and matnight disable in the auto folder there are no more bombs but after starting amc gdos there is a reset when I choose 4 (Color C27). Choose I the SM124 it goes to the Desktop without problems.

I use an imsg171 ramdac instead of the 170. I've ordered it and I'm waiting. but I guess that's not the reason.


@tOriman ... I can send you my card (all GALs have sockets 1-5) and a driver install disk ...

All pins from GAL IV are connected except for number 19 my guess !?!

14/15/16 are TP17 and 23 are TP15 (all go further in the circuit) ...

Hi Frank,

frank.lukas wrote: 24 Apr 2023 12:40 I swapped the four gals 1 to 4. If I swap the IV GAL alone, I get the color c27 option in the selection.
It loads the matrix bios first, then comes the selection and then amc gdos starts up and then two bombs comes and there is a reset. With matmouse and matnight disable in the auto folder there are no more bombs but after starting amc gdos there is a reset when I choose 4 (Color C27). Choose I the SM124 it goes to the Desktop without problems.

I use an imsg171 ramdac instead of the 170. I've ordered it and I'm waiting. but I guess that's not the reason.


@tOriman ... I can send you my card (all GALs have sockets 1-5) and a driver install disk ...

When you swapped all the GALs except the IV - works Atari OK? If yes then four GALs are OK too. I don't know how should look JED file for GAL_IV because I don't have second chip to unblock and compare. At first glance everything looks great. Gwinter mentioned some problems with the card in the past. Maybe this GAL is just defective? Maybe one of the bits changed state (bit-flip)? Without a second GAL to determine this 100% is impossible.

Please wait for IMSG170 - I hope it will help...

:) I have one card at home. Enough. artik_wroc will make some checks of his M110 too.

GAL_IV should have most of pins connected because many of them are feedbacks - not outputs. I'll check it later with my tracer. Maybe I wrote a little inaccurately about those "short" JED files for GAL_I and GAL_IV.

I'll PM you later with some M110 questions. I need to connect properly this card to my MegaST using VGA monitor (I don't have ECL one)

Greetz
tOri