Hi Mike, thanks for the great suggestion. I didn't think about checking the SBus card PROM with OBP other than collecting docs. Hope it may show the register mapping in the card PROM properties.
I don't have the card but I'm thinking of buying a National Instrument GPIB SBus card (part #: SB-GPIB-TNT) to play with OBP. There are around ten of them on ebay now and at least two different revisions exist (though the main chips are the same and their docs are available online). Here are some of them with board pictures showing the DMA controller and GPIB controller:
- sw
Hello,
On Sat, 13 Jun 2020 20:19:40 -0700
SungWon Chung <lucky.cimon%gmail.com@localhost> wrote:
> Yes, I have most docs but not complete. I'm hesitating between SCSI GPIB
> and SBus GPIB (both from National Instruments). Luckily, both are pretty
> cheap and easy to find at ebay nowadays.
>
> All docs on TNT4882 GPIB controller and LSI SBus DMA controller L64853A
> chip on the SBus GPIB card are available online. So, making the body of
> the drivers are doable but can't find necessary information for the
> initialization part (like SBus I/O memory mapping for accessing the GPIB
> controller registers on the SBus card). Still no clues other than reverse
> engineering Solaris 2 drivers. Would there be an easy way to figure it
> out?
Do you have one of those SBus cards?
They tend to set device properties with more or less meaningful names
for address ranges - I wrote drivers for things like the AG-10e based
on just that.
I really need to dig the card up and have a look at what the ROM tells
us. Often there are forth words defined on the device node which can be
examined ( see <word> etc. )
That said, I'm not sure my card has the DMA chip.
have fun
Michael