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schlopper

24 karma · joined April 13, 2020

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schlopper··on The History of CP/M (1980)
Interesting - CP/M has a fixed sector size of 128 bytes. In CP/M 2.x, if your physical sectors were a different size, you'd have to implement deblocking code in your BIOS. CP/M 3.x still used 128 byte sectors, but supported specifying the physical sector size and would do the de-blocking for you.

I'm guessing MSX-DOS uses the 128 byte records/blocks to make it easy to read foreign disks and to be able to create disks readable on other platforms?

schlopper··on The History of CP/M (1980)
Having just completed a CP/M 3.0 BIOS for my homebrew Z80 machine, I am in awe at the amount of planning and foresight that went into it. The fact that you can write a piece of custom code in 2024 (for hardware that didn't even exist back then) and link it with the Digital Research binaries from the 70's to have a fully-functional and compatible O/S that is able to run almost any software written for CP/M in the past 40 years is just crazy.

Unlike CP/M 2.x, CP/M 3 allows for banked memory and disk data/directory buffers, resulting in a lot more usable memory for applications (Transient Program Area) and faster disk access. Although with an SD/CF card, the CPU is more the bottleneck than the disk I/O.

The project was both nostalgic and informative - trying to maintain performance while counting every byte of code has shed some great insights into low-level O/S design.

schlopper··on How we built DMARC Management using Cloudflare Workers
You can get started easily using something like:

https://github.com/gutmensch/docker-dmarc-report

schlopper··on Poll: Where do you live?
Now now... You'd just be pandering to the separatists.
schlopper··on A German man is keeping $60M in Bitcoin from police
Something's off about the article:

"Authorities have seized his digital wallet"

How do you seize a digital wallet when all you need to access or recreate it is a private key (or recovery text)? What have they seized exactly?

schlopper··on I'm booting my Raspberry Pi 4 from a USB SSD
PXE Boot w/ NFS root - you won't get the bandwidth (about 112MB/s over gigabit Ethernet), but you'll definitely see the response time improvements (IOPS + latency).
schlopper··on macOS in QEMU in Docker
QEMU/KVM/VFIO has come a long way. If you have a MacOS-supported GPU and working IOMMU (AMD) or VT-d (Intel), then you can achieve near-native MacOS performance for your CPU/GPU combo.