21 Apr
2024
21 Apr
'24
5:08 p.m.
Mike, any tips or guidelines for running an emulated PDP on a Raspberry Pi ?
Regards,
Tarek Hoteit
On Apr 21, 2024, at 08:08, Mike Katz via cctalk
<cctalk(a)classiccmp.org> wrote:
Well my PDP-8 was built in 1974 and is still running (with careful maintenance). My
PiDP-8/I has been up and running continuously with a Raspberry PI 3B running it for about
5 years now. My PiDP-11 has been up and running with a PI-4B for more than 4 years
continuously.
Though I agree with your comment that the PDP-8 was built to last (just ignore the
disintegrated foam used between the motherboard and the case or on the case top) I have
PCs that are more than 10 years old that are still running.
As for the RP2040 being cheap crap, I beg to differ with you. It is a solid chip,
produced in 10s of millions at least. And, I would bet, a better quality chip than your
Z-80, if due only to improved IC manufacturing technologies.
Just because it's old doesn't make it good. I worked on a 32KHz 4 Bit CPU (about
20 years ago) where the development hardware was very unstable and the tool chain not a
whole lot better.
Early Microsoft and Lattice C compilers for the PC were buggy as hell. If you want I can
list a few bugs from each of them in another thread.
One of the biggest features of the Z-80, the extra register set, was rarely used in open
source software in order to maintain compatibility with the 8080.
Some of the early Z-80 CP/M tools did not work because they were derived from 8080 tools.
After time the tools got better. That is the case with any piece of software. If it
doesn't become obsolete and if maintained it will get better over time.
On 4/21/2024 1:09 AM, ben via cctalk wrote:
On 2024-04-20 8:33 p.m., Mike Katz via cctalk
wrote:
For anything more sophisticated than your coffee pot the RP2040 from Raspberry Pie is a
fantastic little chip, dual core 133 MHz Cortex M0+ with 8 PIO engines, 264K of RAM, ADC,
UART, SPI, I2C all for under a dollar. I designed a fully functional RP2040 with 16 Mb
flash for under $2.00. In large enough quantities that's encroaching on 8 bit PIC
territory at over 1000 times the memory and CPU power.
I am wishing for a Quality Product, cheap crap is not always better.
USB comes to mind.
256Kb ram is only 32K 64 bit words. Cache memory never works.
My $5 internet toaster, just exploded after 3 days.
So what? Just buy the new model that works with windows 12.
Download a buggy new tool chain. The Z80 tools worked.
The PDP8 was built to last. 50+ years and going strong.
NOT the crappy PI PDP-8 or PDP-10. I give it 2 years max.
Now a PI style computer with compact FLASH x 2, NO USB
and 2 MEG ram , real serial and printer ports that will work
in a noisy industrial setting, would be quite usefull.
I'd pay even $3 for it. :)