Re: Wolf. 3D IIGS - NEWS Update!

[dempson@atlantis.actrix.gen.nz (David Empson)]

In article <4bvbbq$srr@uuneo.neosoft.com>,
Mark Manning <markem@starbase.neosoft.com> wrote:
> 
> : with 1 card out on the market doesn't work well.. can you add more than 8
> : megs on a GS? No.. can you add better sound than whats included? You can
> 
> Actually, the //gs will go up to 16mb of memory.  Applied
> Engineering had such a card and actually, if you put nothing
> but AE memory cards into the //gs you could have gone to 64mb
> - but you would not have been able to read anything from disk.
> Because all of the slots were filled.

You are talking about a different sort of memory card.  The IIgs's own
address space is 16 megabytes, but the Memory Manager (and possibly the
hardware) will not support fast RAM beyond 8 MB, for a total of 8 MB +
128 KB of slow RAM (and up to 1 MB of ROM, including a 512KB ROM disk).

Slot-based RAM cards cannot be used to execute code, only as data
storage, and then only for programs that support them (it is unlikely
that there are any IIgs native programs that support these cards
directly).  They can be used as RAM disks, but you are better off
using a large hard drive, rather than wasting slots and power on huge
RAM cards.

> : megs on a GS? No.. can you add better sound than whats included? You can
> : add stereo and recording but you surely can't add another sound chip.. Can
> 
> Well, actually, your statement disputes itself.  You asked if
> we could add better sound than what is included and then blow
> off adding a stereo sound card which (I might add) has another
> sound chip on it.

Some do, but most don't.  They just provide amplification and stereo
demultiplexing for the Ensoniq chip on the motherboard.

> : you add pipeline cache (Or ANY hardware cache for that matter) to
> : the //gs 
> 
> Actually no.  You are correct here.  However, the //gs (as
> well as the entire family of any computer system you wish to
> name) actually have a built in cache.  The difference here
> being that earlier computers did not have a cache outside of
> the cpu itself _and_ the caches were quite small (usually
> holding no more than one or two additional instructions.

There is no cache of any kind built into the 6502 family.  There is an
instruction pipeline, of sorts: the last cycle of one instruction can
overlap the fetch of the next opcode.  I'd hardly call that a "cache".

By comparison, the 8086 has a pipeline that can hold several
instructions waiting for execution, and more recent 80x86 family
members provide actual caches inside the processor (so that loops can
execute from within the cache, for example), with support for
additional external cache RAM.

> Still, you are right about no external cache.  However, the //gs was
> never intended to use an external cache, just the small (about
> 0.5k I believe) amount of memory reserved as a buffer for the
> cpu to perform its reads and writes with.

Pardon?  There is no cache at all in the IIgs, unless you add an
accelerator card.

> Also, updating the BIOS (which is simply the Basic Input/Output
> System - and not meaning "Basic" as in the language BASIC but
> rather as in "The basis from which we start") is nothing more
> to us than downloading the newest release of the GSOS.  Which,
> granted there hasn't been one for a while, is really no
> different than your downloading a new BIOS.  Or maybe it would
> be more equivalent to downloading a new FST?

The BIOS in the PC is more like the monitor and I/O firmware in the
IIgs.  This cannot be updated without a ROM replacment.

The toolbox and operating system are at a higher level.  GS/OS could
be compared with MS-DOS, which is not part of the BIOS, and the
Toolbox could be compared with MS-Windows.  These are easy to upgrade,
by patching out the ROM-based tools with newer versions, for example.
(GS/OS is entirely loaded from disk.)

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand