Subject: Re: ARM 7100/7500

From: Alan Cox <[email-masked]>
Date: Thu, 12 Jun 1997 10:25:10 +0100 (BST)

> and onward MMU's; I think they are basically commenting on the ability
> to set protection down to 1K granularity and some of the protection
> mechanism bits; Apple specified them quite heavily for the Newton and
> its wacky OO based OS.

Ok

> P.S. I believe the 7100 is destined for the new PSION 5 handheld -
> 'Linux in your pocket (TM)' ?

Yes this has been funny and we've been baited PSION people. PSION kept the
story terribly secret until last week while Cirrus Logic (who make the
chips) have been telling everyone for months.

In this case Im looking at it for a DIY wearable - that or the 7510. Both
are cheap and have a pile of GPIO pins (enough to do IDE on ;)) and are small
and compact. 

The 75xx looks as if you can plug a twiddler into its keyboard connector,
irda on for the networking, some DRAM on the ram controller, a ROM on the
memory bus and some kind of display - the only problem is that it looks as
if the builtin lcd controller wouldnt be able to drive a scanning led
heads up display.

We've got a certain interest in tiny boxes here (see http://toy.cabi.net)
-  163.164.160.253 if you have trouble as something got crap into the
DNS for a while.

The dream is to stick the main board and batteries on top of a 2.5" disk

---

From: Alan Cox <[email-masked]>
Date: Thu, 12 Jun 1997 11:23:08 +0100 (BST)

> Have you looked at using a Xilinx to do the interfacing - possibly with
> the head up display? I believe they do some 3.3V things now - although
> they are difficult to get hold of.

No but I know folks who use a lot of Xilinx bits

> Do you have someone with a cheap PCB fab - its just that producing a
> decent multilayer board nice and compact could cost as much as all the
> bits.

PC fab is going to be the problem, especially if we have to make it a
multilayer board. 

> I like the look of that IBM palmtop - why have I never seen articles on
> it?

Its an IBM Japan only product - tho the slightly larger Toshiba Libretto
which is pentium based gets a US launch soon.

> Yes you could use a 2.5" disc; but the cost of memory is so low now and
> Linux is so compact that it might be worth considering what you could do
> with battery backed DRAM or FLASH. Probably less physical hastle, easier
> to drive and you don't have a gyrascope strapped to your belt :-)

Memory costs for a PDA are low - 8Mb battery backed is fine, but if its
going to be a full functional linux box the 330Mb is about minimum IMHO.

Alan