I have two PC Chips M520 board - one works but BIOS displays "Keyboard error or no keyboard present" at POST. I desoldered the KBC and soldered socket there but the problem is the same with another KBC. Communication between KBC and keyboard is OK - the NumLock LED goes on/off when NumLock key is pressed.
The other board only beeps - same as if there's no memory installed.
Does anyone know how can these boards be fixed?
Two PC Chips M520
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere
UniFlash - Flash anything anywhere
Press F1 to continue ?Rainbow wrote:I have two PC Chips M520 board - one works but BIOS displays "Keyboard error or no keyboard present" at POST.
(Long shot) Tried changing the A20 mode?I desoldered the KBC and soldered socket there but the problem is the same with another KBC. Communication between KBC and keyboard is OK - the NumLock LED goes on/off when NumLock key is pressed.
(Longer shot) Does this BIOS support exchange of K/b and PS/2 mouse ?
You've tried both SIMM and DIMM - checked for bent contacts, or debris in socket causing a short ?The other board only beeps - same as if there's no memory installed.
and of course you've swapped the BIOS ROM?
Tested patched BIOSes. Untested patched BIOSes.
Emails *will* be ignored unless the subject line starts "Wim's BIOS forum"
Emails *will* be ignored unless the subject line starts "Wim's BIOS forum"
Keyboard does not work.Press F1 to continue ?
I have tried something more today: removed Flash ROM, put into my MS-5120 board. Saved BIOS, opened in MODBIN and changed defaults to halt on no error and boot from floppy. Then flashed and put back. The board now boots from floppy and HDD.
Booting Windows 95 stops at HIMEM.SYS: Cannot control A20 line.(Long shot) Tried changing the A20 mode?
Most probably not because KB connector is DIN and mouse is PS/2. It does not support USB keyboard too.(Longer shot) Does this BIOS support exchange of K/b and PS/2 mouse ?
Then took my old ALR Ranger notebook, ran Turbo Pascal and do some quick-and-dirty programming and testing of the KBC (ports.lst file from Ralf's Brown Interrupt List is great thing

The $AA command (initiate self-test) passed OK.
After sending $AB command to the KBC (initiate interface test), it returned $02 - keyboard clock line stuck high.
Using a multimeter, the clock line is really stuck high. It's OK on the second board. Maybe 74HC05A inverter is bad.
I tried 128MB DIMM but it didn't work even in the working board. Tried 2 SIMMs in both banks. I tried swapping BIOS and RTC with the other board.You've tried both SIMM and DIMM - checked for bent contacts, or debris in socket causing a short ?
and of course you've swapped the BIOS ROM?
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere
UniFlash - Flash anything anywhere
Downloaded the datasheet for the inverter - it's really bad. The input on pin 1 is high (5V) and the output pin 2 too - it should be inverted (0V). I'm going to replace it either with new one or with the one from the other board.
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere
UniFlash - Flash anything anywhere
Sorry, bad joke. That's what it usually says. "No keyboard - press F1 to continue"Rainbow wrote:Press F1 to continue?
Keyboard does not work.

It sounds as though you are making progress - good luck with replacing the inverter.
Tested patched BIOSes. Untested patched BIOSes.
Emails *will* be ignored unless the subject line starts "Wim's BIOS forum"
Emails *will* be ignored unless the subject line starts "Wim's BIOS forum"
Replaced the inverter. The new one is DIP, the old one was SMD so there are now 14 wires sticking out of the board with the inverter on the top
Keyboard and PS/2 mouse works, played even Duke Nukem 3D
But HIMEM.SYS still does not work: "Unable to control A20 line".

Keyboard and PS/2 mouse works, played even Duke Nukem 3D

Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere
UniFlash - Flash anything anywhere
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- The New Guy
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M520 will take the 16-chip, 32MB DIMM, or the *special 64MB* ones that AJZ has
. I have SIMMS in mine...4-16MB in one and 2-32MB in the other.
Good luck on the keyboard problem!!

Good luck on the keyboard problem!!
It was 74HC05A, replaced with National Semiconductor MM74HCT05N.
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere
UniFlash - Flash anything anywhere