Hi all,
I think I am running into an IRQ conflict with my ST-412 MFM Disk and Card.
What I see out from some manuals, the ST-412 card assigns IRQ5. (https://nerdlypleasures.blogspot.com/2016/05/working-with-st-506-interface-mfm-hard.html)
See ST505 Chapter, 3rd paragraph.
The IBM PC and XT BIOSes do not support hard drives and know nothing about them. Support is added via a BIOS extension found on a hard drive controller card. The default settings for XT controller cards are I/O 320, IRQ5 and DMA3. An alternative I/O setting is at 320 and some cards allow the IRQ to be set to 2. The latter is necessary when using an MFM controller in a Tandy 1000, which uses IRQ5 for video (Ghostbusters will not work properly if IRQ5 is disabled for video, as it can be on the SX and TX). The controller's BIOS extension also provides hard drive tables for the types of hard drives it supports.
IRQ5 is per default assigned on 80286 mainboard to LPT2 or LPT3 (https://en.wikipedia.org/wiki/Interrupt_request)
Is there any way to solve it?
My symptoms are, that the card wont be initialized and therefore also no "red" led flashes on the MFM HDD.
So the HDD is not recognized
BR
Dieter
I think I am running into an IRQ conflict with my ST-412 MFM Disk and Card.
What I see out from some manuals, the ST-412 card assigns IRQ5. (https://nerdlypleasures.blogspot.com/2016/05/working-with-st-506-interface-mfm-hard.html)
See ST505 Chapter, 3rd paragraph.
The IBM PC and XT BIOSes do not support hard drives and know nothing about them. Support is added via a BIOS extension found on a hard drive controller card. The default settings for XT controller cards are I/O 320, IRQ5 and DMA3. An alternative I/O setting is at 320 and some cards allow the IRQ to be set to 2. The latter is necessary when using an MFM controller in a Tandy 1000, which uses IRQ5 for video (Ghostbusters will not work properly if IRQ5 is disabled for video, as it can be on the SX and TX). The controller's BIOS extension also provides hard drive tables for the types of hard drives it supports.
IRQ5 is per default assigned on 80286 mainboard to LPT2 or LPT3 (https://en.wikipedia.org/wiki/Interrupt_request)
Is there any way to solve it?
My symptoms are, that the card wont be initialized and therefore also no "red" led flashes on the MFM HDD.
So the HDD is not recognized
BR
Dieter