Re: RP2350 and Pico 2 - things missing

On 30/08/2024 20:50, mm0fmf wrote:

On 30/08/2024 15:45, The Natural Philosopher wrote:

On 30/08/2024 15:39, mm0fmf wrote:

On 30/08/2024 14:28, John Aldridge wrote:

In article <20240829191334.570e88c7507598ffe5b28d87@eircom.net>,
steveo@eircom.net says...

    Portable code should only rely on the standards not
implementations, some very weird possibilities are legal within the
standard.

>
Heh, yes. I worked for several years on a machine where a null pointer
wasn't all bits zero, and where char* was a different size to any other
pointer.

>
    That rings vague bells, what was it ?

>
Prime. It was word, not byte, addressed, so a char* had to be bigger.
>

I used a Prime750 at Uni. But only undergrad tasks in Prime BASIC and some Fortran. It seemed quite fast at the time in timeshare mode with plenty of undergrads using it. But the CPU was only as fast as an 8MHz 68000!
>

That is the staggering thing. CPU performance in the mini era wasn't that hot at all.
>
I see someone has made a Pi PICO emulate a range of 6502 based computers - apple II etc.
>
I am fairly sure a PI Zero could outperform a 386 running SCO Unix...and that was pretty comparable with - if not better than - a PDP 11.
>
>

 The CPUs may not have had stunning performance but were generally quite a bit quicker than the Z80/6502s of the day. The real performance came from having disks and ISTR hardware assisted IO. i.e. the CPU didn't have to poll or handle IRQs from each UART but there was something helping. It's all so long ago now I forget the details. What I do remember was it was around 1985 when someone lit the blue touch paper and the performance of micros started rocketing.   Though if you started 10 years before me there will have been something that was when performance took off for you. I think everyone has some point in their memory when things started to go whoosh!
 In 1989 I was writing Z80 assembler to control medical gear. All the code took about 45mins to cross assemble and link on a Unix system running on a Vax 11/730. In 1990 we got a 25MHz 80386 running DOS and the same source took under 3mins to cross assemble and link.  The bottleneck went from the time to build the code to the time to erase, download and burn the EPROMS.
 

Yes. I was writing C and assembler for a 6809 cross complied on a PDP/11.
We had PCS as serial terminals and text editors.
Compile was very slow compared to on a PC.
The thing was that until the 386 Intel CPUs didn't have the big boy features.  After that they did.
Even an old IBM mainframe could be emulated under AIX on a PC.
I did some work on a Vax running Unix too. Better, but still pretty awful
--
I would rather have questions that cannot be answered...
...than to have answers that cannot be questioned
Richard Feynman