Re: Xi 8088 - The improved version of my XT board

[Sergey <skis...@gmail.com>]

EMS uses memory window in the first 1 MiB, so there is no reason why
it won't work with V20 or 8088 as long as the card can work in ISA 8-
bit slot.

Thanks,
Sergey

On Sep 25, 9:07 pm, "..I'd rather be coding ASM!" <uri...@deviate.fi>
wrote:
> Hi Doug,
>
> I shall keep this in mind when the new v2 Xi board is built. I was mainly
> wondering though if EMS could be used on a NECV20 off the ISA bus.
>
> Thanks. Nifty idea :) I've seen a Rampat board previously. I wish I knew
> where it's gone (Might be at dad's back in Perth (?)) but I have somewhere
> a 16bit ISA 2mb intel above board ram expander.
>
> Al
>
>
>
>
>
>
>
>
>
> On Tue, 25 Sep 2012, Douglas Goodall wrote:
> > Al,
>
> > I have a huge pile of AST Rampage boards, some of which are ISA 8-bit, and would
> > provide several megs of extended or expanded or backfilling memory.
>
> > Also a number of small boards meant to backfill 640K.
>
> > If any of these would be useful to you, let me know...
>
> > Douglas Goodall
>
> > On Sep 25, 2012, at 4:00 PM, ..I'd rather be coding ASM! <uri...@deviate.fi> wrote:
>
> >> Hi Sergey,
>
> >> Interesting. I've an old amstrad 286 I've recently got working again and have been playing with UMB/EMS memory windows in tasm. I also have an Orchid Turbo 286 board I've previously had working in an NCR PC 4i
> >> and am dead curious if it'd work in the V1 sergey XT hence the tyre kicking.
>
> >> A UMB/EMS board would be *very* nifty.
>
> >> Thanks. :)
>
> >> Al.
>
> >> On Tue, 25 Sep 2012, Sergey wrote:
>
> >>> Al,
>
> >>> The Xi board allows mapping some RAM above 640K in 0C0000h - 0EFFFFh
> >>> area, providing up to 192 KiB of UMBs. Part of this area might be used
> >>> by BIOS extension ROMs or for memory mapped I/O, which limits the
> >>> usable space. For example VGA cards normally use 0C0000h-0C7FFFh block
> >>> for VGA BIOS.
>
> >>> It is possible to eliminate other ROMs (such as XT-IDE BIOS) by
> >>> copying them to the BIOS ROM at 0F0000h-0F7FFFh area (memory above
> >>> 0F8000h is used by the BIOS itself). This will not only save UMB
> >>> blocks, but also the ROM ICs for XT-IDE BIOS (or network boot ROM).
>
> >>> I actually tested the UMB with V1.0 board, using USE!UMBS and DOSMAX:
> >>>http://ftp.sunet.se/pub/simtelnet/msdos/memutil/use-umbs.zip
> >>>http://ftp.sunet.se/pub/simtelnet/msdos/sysutl/dosmax21.zip
>
> >>> This is pretty cool, as it relocates DOS and related stuff to UMBs,
> >>> leaving about 625 KiB of usable lower memory.
>
> >>> Implementing a real EMS (with switchable pages) would require more
> >>> components, and I didn't want to over-complicate the design. But an
> >>> EMS card is an interesting idea for another project.
>
> >>> Thanks,
> >>> Sergey
>
> >>> On Sep 25, 3:09 pm, "..I'd rather be coding ASM!" <uri...@deviate.fi>
> >>> wrote:
> >>>> On Tue, 25 Sep 2012, Sergey wrote:
> >>>>> Good. In this case I'd like to know who else will be interested in
> >>>>> making a backplane?
>
> >>>>> I'll start a separate thread to discuss this.
>
> >>>> I'd be super keen to build one. Some suggestions:
>
> >>>>   - ATX holes so it can be bolted to easy to find PC cases
> >>>>   - AT and ATX connector
>
> >>>> Separate idea.. with the XT v2, is there a way to get 64k EMS to work?
> >>>> Wondering if there's a RAM expander anyone's tried from the v1.
>
> >>>> Al.
>
> >>>> --
> >>>>   --
> >>>>   Al Boyanich
> >>>>   adb -w -P "world> " -k /dev/meta/galaxy/ksyms /dev/god/brain
>
> >> --
> >> --
> >> Al Boyanich
> >> adb -w -P "world> " -k /dev/meta/galaxy/ksyms /dev/god/brain
>
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> --
>   --
>   Al Boyanich
>   adb -w -P "world> " -k /dev/meta/galaxy/ksyms /dev/god/brain