On Wed, Jun 07, 2023 at 05:54:00PM -0400, William Dudley via vcf-midatlantic wrote:
That would take months to boot OS-8.
I have an FPGA implementation and if I run it at 5kcps it boots in a second or two. Takes minutes to do a DIR command though. It will run Focal decently. Instructions average 3 or 4 clocks per instruction, I'm limited by the RasPIs GPIO pin count so have a single 12-bit bi directional bus plus some control signals. Mike
Shouldn't be that slow. Pre 8/E minimum instruction time is 1.5 microseconds or 666 KHz. He is projecting around 10k CPS. Couldn't tell if cycle is instruction or internal clock.
Booting OS/8 is more limited by speed of media than processor. For RK05 call it 2 seconds to boot. Simple scaling of 666/10 = 66.6 says 2 minutes to boot. Could be slower if multiple clocks per instruction or faster if mostly waiting for IO to complete. Speed will depend on how peripherals are simulated. PDP-8 could use databreak (DMA) or programmed IO based on device.
Slower than a PDP-8/S at maximum of 37.6k instructions per second. People did use the 8/S though haven't found anybody fondly talking about that model.
On Wed, Jun 7, 2023 at 5:38â¯PM Mike Rieker via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Hi All, Some of you might have an interest in my PDP-8/V project. https://www.outerworldapps.com/pdp8v Not exactly vintage but definitely retro! Mike Rieker Beverly, MA