[rescue] Sun 3/160 and CADDStation 32 deskside

[Alan Perry]

Thanks.

I have since found that I have a 3/160 memory board to add to the 4M on the 3/160 board I am using in the CADDStation. However it is broken and I am trying to debug it.

alan

> On Aug 13, 2025, at 03:00, Romain Dolbeau <romain at dolbeau.org> wrote:
> 
> Le mar. 3 juin 2025 à 09:11, Romain Dolbeau <romain at dolbeau.org> a écrit :
>> I don't have a definitive answer, but the Sun Hardware FAQ says in part 1:
>> 2/160 => "2/160 upgradeable to a 3/160 by replacing the CPU board"
>> 3/160 => "Upgradeable to a 3/260 by replacing  CPU and memory boards."
>> 3/260 => "Upgradeable to a 4/260 by replacing the CPU board"
> 
> After playing a lot with the ROM and the Sun 3 architecture, there's a
> reason for which the 3/260 won't share memory boards with the 3/160:
> parity vs. ECC.
> 
> * Carrera (3/160) and Prism (3/110) PROMs are hardwired to use parity.
> * Sirius (3/260) PROM is hardwired to use ECC.
> 
> The architecture manual
> (<http://www.bitsavers.org/pdf/sun/sun3/Sun-3_Architecture_Manual_Ver_2.0_May85.pdf>)
> permit both, but with the ROM selftest won't allow the use of the
> "wrong" type.
> In theory one might rebuild a PROM with that part changed to
> accomodate whichever board, but that's probably more effort than just
> tracking the appropriate board.
> 
> Cordially,
> 
> --
> Romain Dolbeau