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Help with Sergey's 8-Bit FDC and Serial Port board.

Have you tried a Gotek FD emulator? LCD mod on that and it’s great alternative to old floppies. Couple that with a Greaseweasel to capture images from other floppy drives and you’ll have a great system.
 
fjk61011 said:
I just tried in a DTK XT clone. It works. F2 came up and I changed drive 0 to 360 k. Was able to boot from a dos floppy. Got mine from Bulgaria too. Seller very helpful.
Click to expand...
Does the BIOS startup message appear on the 5150 now too?
 
The story so far:

Sergey's FDD controller does not work in my 5150.

A BASF HDD works in the 5150.

The ROM chip seems to be an AMD one. I tried to change it for a ROM from another 5150. However disaster struck and one of the centipede legs fell off.

Sergey's FDD controller does work in my DTK XT clone.

A BASF HDD does not work in the DTK XT clone. There is a NEC V20 in this PC.

I think I'll stop there for the night.
 
fjk61011 said:
Works in the XT clone. Doesn't work in 5150, I get D000 ROM and goes on to post.
Click to expand...
The "D000 ROM" is an error message produced by the power-on self test (POST) of the 5150 motherboard's ROM.
The POST, when out looking for BIOS expansion ROM's, found one at address D0000, but discovered that the contents are not as expected.

"Contents are not as expected" can be caused by either:
- A damaged ROM
- An address conflict

Do you have two cards configured to have their ROM start at address D0000 ?
 
If you can, Try re-flashing the ROM in your 5150, If not try re-flashing in your XT clone and try the controller in your 5150 again.
 
modem7 said:
And no other cards except for the video card ?
Click to expand...
fjk61011 said:
Correct
Click to expand...
The video card is not going to have a ROM starting at address D0000, so confirm for us that the EEPROM in Sergey's card is what is set to start at D0000.

If confirmed, the question is as I see it is, which of the following two is happening:
- When Sergey's card is placed in the 5150, something is corrupting the contents of the EEPROM on the card.
- The EEPROM contents are not corrupted; there is simply an address conflict going on within the 5150.

The first possibility would become evident if the card is moved back to the clone.
 
I doubt it's corruption as the controller works in the XT Clone, Possibly an address conflict or:
It's the way the seller is flashing the ROMS
Some other issue with the controller that the 5150 falls over on.
 
Last edited:
Malc said:
I doubt it's corruption as the controller works in the XT Clone,
Click to expand...
Ah yes. I just reread the thread. At post #19, the OP did not need to reflash the EEPROM.

Malc said:
Possibly an address conflict ...
Click to expand...
If we look at the 'ROM address conflict' hypothesis:

Fact: The only cards in the IBM 5150 are a CGA card and Sergey's card.
Fact: The POST in the IBM 5150 is seeing, at the least, the 55 AA at the start of a ROM at D0000.
Assumption (at this time): The OP's card is set to start its EEPROM at D0000h. (Good assumption - no other cards with a BIOS expansion ROM.)

Conflict possibilities:
- A faulty CGA card that is decoding part, or all, of the D0000-D1FFF address space.
- A faulty 5150 motherboard that is decoding part, or all, of the D0000-D1FFF address space.

In both cases, Sergey's card would have to be 'winning the tug-of-war' conflict for at least the first two bytes (55 AA).

Malc said:
... the way the seller is flashing the ROMS ...
Click to expand...
I can't think of a flashing related issue that would result in the card's EEPROM operation in an XT clone, and corrupted reads of the same EEPROM when the card is fitted to a 5150 motherboard.

Malc said:
... Some other issue with the controller that the 5150 falls over on.
Click to expand...
In post #18, BarryM's, "No problems with the replacement board in the 5150 and the BIOS did appear with no other cards with ROM sockets plugged in." suggests that a problem is not expected.

However, maybe some soft of issue with the particular sub-revision of 5150 motherboard. Always a possibility, which I'm reminded of by with things like:
- What exactly was IBM fixing at [here].
- What's [this] about?

Changing the video card might be a good first step (easy to do).

Seeing the affect of changing the EEPROM's start address to E0000 (E0000 available in the OP's current 2-card configuration).
 
If it helps, I ran my Sergey FDC card in a 1st gen 16-64kb 5150.

The machine was set to my minimum config
  1. Paradise VGA
  2. Lotech 1 Mb (640k + E000-EFFF UMB)
  3. Sergey FDC @ C800
  4. V20 + 3rd rev BIOS
 
modem7 said:
If we look at the 'ROM address conflict' hypothesis:

Fact: The only cards in the IBM 5150 are a CGA card and Sergey's card.
Fact: The POST in the IBM 5150 is seeing, at the least, the 55 AA at the start of a ROM at D0000.
Assumption (at this time): The OP's card is set to start its EEPROM at D0000h. (Good assumption - no other cards with a BIOS expansion ROM.)

Conflict possibilities:
- A faulty CGA card that is decoding part, or all, of the D0000-D1FFF address space.
- A faulty 5150 motherboard that is decoding part, or all, of the D0000-D1FFF address space.

In both cases, Sergey's card would have to be 'winning the tug-of-war' conflict for at least the first two bytes (55 AA).
Click to expand...
Make's sense

modem7 said:
I can't think of a flashing related issue that would result in the card's EEPROM operation in an XT clone, and corrupted reads of the same EEPROM when the card is fitted to a 5150 motherboard.
Click to expand...
I have seen / Had this issue before, IMO it's worth trying a Re-flash in situ preferably in the 5150 or in the XT clone just to rule it out. Also there is a possibility of a 'borderline' IC in the ROM circuit of the controller which the 5150 post is picking up on.

modem7 said:
In post #18, BarryM's, "No problems with the replacement board in the 5150 and the BIOS did appear with no other cards with ROM sockets plugged in." suggests that a problem is not expected.
Click to expand...
"replacement board"

modem7 said:
Changing the video card might be a good first step (easy to do).

Seeing the affect of changing the EEPROM's start address to E0000 (E0000 available in the OP's current 2-card configuration).
Click to expand...
All worth a try.
 
Hello everyone I'll read the new posts later. I'm watching Artemis I.

I only have one CGA card which I transfer to the XT.
 
Malc said:
Make's sense


I have seen / Had this issue before, IMO it's worth trying a Re-flash in situ preferably in the 5150 or in the XT clone just to rule it out. Also there is a possibility of a 'borderline' IC in the ROM circuit of the controller which the 5150 post is picking up on.


"replacement board"


All worth a try.
Click to expand...
I only have one CGA. I use that in the XT clone and Sergey's card works.
 
fjk61011 said:
Not sure if it's an EEPROM. Don't have a programmer for a EPROM
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What does it say on the ROM on your controller ?, Is it an ATMEL AT28C64B ?, If it is you can use XTIDECFG.COM from the XUB download site to flash the ROM in situ and preferably do it on your 5150.
 
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