VOGONS


Reply 20 of 42, by quicknick

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Where did you get it at that price? Do they have one more? 😁
Also, one of the dip switches allows to choose between 0 and 1 wait states, and there is also a jumper for ram compatibility - forgot which one, but it's all in the manual.

Reply 21 of 42, by Jed118

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I got it from Poland. The board does require some work though, I think it has to do with memory timing. Which version of the manual are you reading? Mine mentions jumpers, but no DIP switch. I'd love to have a look at it and set it to 1 wait state, as when I put 4x256 (for 1Mb) I get "invalid Switch" error JUST as the ram count begins. If I put in 70NS 1Mb SIMMS, it boots OK but later it crashes. I put 60NS RAM in there now and it's quite a bit more stable.

Please share manual! 😁

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What's for sale? my eBay!

Reply 22 of 42, by Jed118

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Also, if you have another compatible 286 board, I'll outright trade you (or even a low spec 386SX).

Youtube channel- The Kombinator
What's for sale? my eBay!

Reply 24 of 42, by Retroit

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Sorry for bumping old thread. Do you manage to repair you MB? I got the same MB, but it has broken BIOS and on vogons none of listed aren't work with my MB. Could you post here a BIOS dump of all you MB 286 with Headland chipset?

Reply 25 of 42, by quicknick

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Keatah wrote on 2018-04-17, 03:04:

Can you post (or pm me) edge-on photos of the crack? I'd like to see how close the wires are. And I've repaired microSD traces smaller than the bond wires in standard ICs.

Sorry for being a few years too late, somehow I managed to miss your post. I actually thought about this and took some macro photos, but no bond wires can be seen.

Retroit wrote on 2021-08-03, 09:33:

Sorry for bumping old thread. Do you manage to repair you MB? I got the same MB, but it has broken BIOS and on vogons none of listed aren't work with my MB. Could you post here a BIOS dump of all you MB 286 with Headland chipset?

I now have another two working Fox M boards, but sadly the original one is still broken (it works if I swap the PAL chip from one of the working boards). So if anyone knows someone that can clone such a PAL, please let me know.
Anyway, here's the BIOS:

Filename
Octek Fox M.rar
File size
45.51 KiB
Downloads
58 downloads
File license
Fair use/fair dealing exception

Good luck with reviving your board!

Reply 26 of 42, by Thermalwrong

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hkzlab has made the DuPAL dumping system: https://github.com/DuPAL-PAL-DUmper
It goes through all pin combinations to derive the full function of a PAL chip.

That would require putting together the PCB, but it's really great that there's a possible solution now 😀

Reply 27 of 42, by Deksor

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This looks really interesting !

I think I'm gonna build my own and try to reverse engineer PALs I see on various things

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 28 of 42, by Retroit

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quicknick wrote on 2021-08-07, 20:10:
Sorry for being a few years too late, somehow I managed to miss your post. I actually thought about this and took some macro pho […]
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Keatah wrote on 2018-04-17, 03:04:

Can you post (or pm me) edge-on photos of the crack? I'd like to see how close the wires are. And I've repaired microSD traces smaller than the bond wires in standard ICs.

Sorry for being a few years too late, somehow I managed to miss your post. I actually thought about this and took some macro photos, but no bond wires can be seen.

Retroit wrote on 2021-08-03, 09:33:

Sorry for bumping old thread. Do you manage to repair you MB? I got the same MB, but it has broken BIOS and on vogons none of listed aren't work with my MB. Could you post here a BIOS dump of all you MB 286 with Headland chipset?

I now have another two working Fox M boards, but sadly the original one is still broken (it works if I swap the PAL chip from one of the working boards). So if anyone knows someone that can clone such a PAL, please let me know.
Anyway, here's the BIOS:
Octek Fox M.rar
Good luck with reviving your board!

Thank you for BIOS dump. I'll try it as I get some free time.

Reply 29 of 42, by SSTV2

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From

quicknick wrote on 2022-01-06, 02:47:
Darn, this brings back memories... […]
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Darn, this brings back memories...

The chip labeled 089-001 seems to be common between our boards, but the similarities end here. The Fox M is also equipped with 090-103 and 090-110, whereas your board has a 090-101 and a mysterious/optional one right next to the battery (board works fine without it, from what I understand following the dosforum.de thread). Nevermind that, I guess I'm too tired. That board also dead as a stone, maybe 3rd PAL is not optional after all...

The chipset pins don't look very bad (un-salvageable) at first glance, but it's hard to tell without higher resolution pictures.

I'll attach the chipset's datasheet here, maybe your board is built according to the reference schematic (Fox M obviously isn't, as it features a third PAL).

Obviously, if you manage to get it going, I'm still very much interested in the content of the 089-001 chip. Although I have amassed a bunch of working Fox M boards, I still want to cross the original one off the "to be repaired" list. 😁
Headland GC101-102.pdf

No luck with the PAL chip so far? I went ahead and recreated PAL equation from datasheet, seems to be working as intended at Proteus simulation.

===============================================================================
Chip Diagram
===============================================================================

______________
| RASCASGEN |
RAM1RAS x---|1 20|---x Vcc
RAM0CAS x---|2 19|---x !RAS
RAS6080 x---|3 18|---x !CAS0L
RAS40 x---|4 17|---x !CAS0H
MEMW x---|5 16|---x ERD
RAM1CAS x---|6 15|---x !RAS0
RAM0RAS x---|7 14|---x !CAS1L
EMEMR x---|8 13|---x !RAS1
XA0 x---|9 12|---x !CAS1H
GND x---|10 11|---x XBHE
|______________|
Filename
U49PAL_HEADLAND_286.zip
File size
44.59 KiB
Downloads
47 downloads
File license
Public domain

Reply 31 of 42, by quicknick

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SSTV2 wrote on 2022-01-06, 10:34:

No luck with the PAL chip so far? I went ahead and recreated PAL equation from datasheet, seems to be working as intended at Proteus simulation.

Few days have passed. And another month on top of them. Only today I was able to find time to set up the board and try your JED file, programmed it into a ATF16V8B but no luck unfortunately. The board still gives the "no RAM" error, so I guess there are some differences between the reference design and my board. Could be some pins shuffled around, or maybe different/more functions are implemented.
Thank you very much for your effort!

Reply 32 of 42, by crackintosh

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Hi.
I have the same board FOX M286 and the same problem - PAL 089-001 is very hot when i power-up the MoBo! And also 3 beeps - NO RAM.
I'll try to find the difference between REF-design and this M286 revision. Will trace all 18 signal wires from this PAL chip. If they are the same as REF - then something wrong with SW or chip programming.

Reply 33 of 42, by quicknick

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Hi!
If you manage to reverse-engineer the chip, please let me know. I haven't given up yet on repairing the board, but I just lack the skills to do it so I'm patiently waiting 😀

There might be differences between the ref.design and the Octek board regarding these PALs... There's three of them on the Fox and I think only two in the reference design...

Reply 34 of 42, by crackintosh

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Hi. Problem found!

In EQUATIONS (programm listing for PAL16L8 U49) is missing generation of output signal ERD .
This output signal is also used in equations of RAS0 and RAS1 and RAS .
All this signal are incorrect due missing ERD signal!!!

Reply 36 of 42, by crackintosh

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Not yet. Just finished schematic reconstruction of Delay line circuit that use this 2 PAL16L8.
Now have to write new equations for PLM!
Will contact you when my board will power up with a single BEEP! 😉

Reply 37 of 42, by REDLED

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Hi, I have read out the two PAL from the FOX M 286 Rev 1.1 with the "Retro Chip Tester Professional". See attachment. The project can be found here: https://8bit-museum.de/sonstiges/hardware-pro … tester-english/

I have the same board on the workbench at the moment.

Fox-M-286-Rev-1-1.jpg

Good luck!

Greetings
Redled

Attachments

  • Filename
    Fox_M286_1.1_PAL.rar
    File size
    537 Bytes
    Downloads
    48 downloads
    File comment
    Fox M 286 REV 1.1 PAL1 + PAL2
    File license
    Public domain

Reply 38 of 42, by crackintosh

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                               ______________
| RASCASGEN |
RAM1RAS x---|1 20|---x Vcc
RAM0CAS x---|2 19|---x !RAS
RAS6080 x---|3 18|---x !CAS0L
RAS40 x---|4 17|---x !CAS0H
MEMW x---|5 16|---x ERD
RAM1CAS x---|6 15|---x RAS0
RAM0RAS x---|7 14|---x !CAS1L
EMEMR x---|8 13|---x RAS1
XA0 x---|9 12|---x !CAS1H
GND x---|10 11|---x XBHE
|______________|

Th difference between REF and OCTEK FOX M286 is
additional SN74S51 chip and modified EQUATIONS inside PLM PAL16L8 (U12).
The 74S51 chip EQUATION are:

Y1 = NOT(1A * 1B + 1C * 1D)
Y2 = NOT(2A * 2B + 2C * 2D)

Ok. Let's substitute our signals in EQUATIONS according to our schematics.
Will get:

RAS1 (SIMM12-27) = NOT(RAM0RAS*ERD + RAS0*RAS0) = NOT(RAM0RAS*ERD + RAS0) = NOT(RAS0 + RAM0RAS*ERD)
RAS0 (SIMM34-27) = NOT(RAM1RAS*ERD + RAS1*RAS1) = NOT(RAM1RAS*ERD + RAS1) = NOT(RAS1 + RAM1RAS*ERD)

Subequations "NOT(RAS0 + RAM0RAS*ERD)" and "NOT(RAS1 + RAM1RAS*ERD)" was already implemented inside PAL.
Thus they have to be removed from inside equations.
Will get new definition for RAS0 and RAS1 pin definition (Without NOT, because this signals will be inverted by 74S51 outside):

PIN  13  	RAS1                  COMBINATORIAL             ; OUTPUT
...
PIN 15 RAS0 COMBINATORIAL ; OUTPUT

and new EQUATIONS:

RAS0    = RAM0RAS * /EMEMR * /RAS40
+ RAM0RAS * /MEMW * /RAS40
+ RAM0RAS * /EMEMR * /RAS6080
+ RAM0RAS * /MEMW * /RAS6080

RAS1 = RAM1RAS * /EMEMR * /RAS40
+ RAM1RAS * /MEMW * /RAS40
+ RAM1RAS * /EMEMR * /RAS6080
+ RAM1RAS * /MEMW * /RAS6080

without sum of RAM0RAS * /ERD to RAS0 and without sum of RAM1RAS * /ERD to RAS1
This sum is already implemented outside by 74S51.

Now we have to compile new equations for PAL16L8 using PALASM4.
The resulted JED file must be converted from PAL16L8 to ATF16V8
using PALTOGAL utility, using option "2": PAL16L8 -> GAL16L8

Additional INFO:

JERD(1) = S1 + /S0 + /MIOL + ZWSEL (Implemented inside U13)
JERD(2) = NOT(SWSEL + S1) * (S0 * M/IO) (made by IC gates)

JERD(1) = NOT(JERD(2))

U49.jpg

NOTE: There is no 74S51 simbol in Proteus. Only 74LS51. But they are different!!! I used 74LS51 simbol just as reference!

Final code:

Spoler
;PALASM Design Description

;---------------------------------- Declaration Segment ------------
TITLE U49 RAS and CAS Generation
PATTERN PAL16L8
REVISION 04/12/88
AUTHOR Crackintosh
COMPANY (c) G2 INC.
DATE 12/10/22

CHIP U49 PAL16L8

;* *************** INPUT PINS *********************
PIN 1 RAM1RAS COMBINATORIAL ; INPUT
PIN 2 RAM0CAS COMBINATORIAL ; INPUT
PIN 3 RAS6080 COMBINATORIAL ; INPUT
PIN 4 RAS40 COMBINATORIAL ; INPUT
PIN 5 MEMW COMBINATORIAL ; INPUT
PIN 6 RAM1CAS COMBINATORIAL ; INPUT
PIN 7 RAM0RAS COMBINATORIAL ; INPUT
PIN 8 EMEMR COMBINATORIAL ; INPUT
PIN 9 XA0 COMBINATORIAL ; INPUT
PIN 10 GND ; INPUT
PIN 11 XBHE COMBINATORIAL ; INPUT

;* *************** OUTPUT PINS *********************/
PIN 12 /CAS1H COMBINATORIAL ; OUTPUT
PIN 13 RAS1 COMBINATORIAL ; OUTPUT w/o NOT
PIN 14 /CAS1L COMBINATORIAL ; OUTPUT
PIN 15 RAS0 COMBINATORIAL ; OUTPUT w/o NOT
PIN 16 ERD COMBINATORIAL ; OUTPUT
PIN 17 /CAS0H COMBINATORIAL ; OUTPUT
PIN 18 /CAS0L COMBINATORIAL ; OUTPUT
PIN 19 /RAS COMBINATORIAL ; OUTPUT
PIN 20 VCC ; INPUT
;* --------------- Boolean Equation Segment ------
EQUATIONS
RAS = EMEMR * MEMW * ERD;


RAS0 = RAM0RAS * /EMEMR * /RAS40
+ RAM0RAS * /MEMW * /RAS40
+ RAM0RAS * /EMEMR * /RAS6080
+ RAM0RAS * /MEMW * /RAS6080
; + RAM0RAS * /ERD; Commented, implemented outside by 74S51

RAS1 = RAM1RAS * /EMEMR * /RAS40
+ RAM1RAS * /MEMW * /RAS40
+ RAM1RAS * /EMEMR * /RAS6080
+ RAM1RAS * /MEMW * /RAS6080
; + RAM1RAS * /ERD; Commented, implemented outside by 74S51

CAS0L = /XA0 * RAS40 * RAM0CAS * /EMEMR
+ /XA0 * RAS40 * RAM0CAS * /MEMW;

CAS1L = /XA0 * RAS40 * RAM1CAS * /EMEMR
+ /XA0 * RAS40 * RAM1CAS * /MEMW;

CAS0H = /XBHE * RAS40 * RAM0CAS * /EMEMR
+ /XBHE * RAS40 * RAM0CAS * /MEMW;
Show last 3 lines

CAS1H = /XBHE * RAS40 * RAM1CAS * /EMEMR
+ /XBHE * RAS40 * RAM1CAS * /MEMW;

Attachments

  • Filename
    U13andU49JED.ZIP
    File size
    2.2 KiB
    Downloads
    35 downloads
    File license
    Public domain

Reply 39 of 42, by quicknick

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That's great, thank you guys! I'm away at the moment, but can't wait to burn the code into an ATF and revive my board!

@REDLED, I'll have to read into this "Retro Chip Tester Professional", and also I find it interesting that your board lacks the third PAL (the one behind the ISA slots), and one of the other two seems to be a different version to what I've seen so far.