The floppy disk usually made this straight up honking noise . I had a V20, but at 10Mhz. Never had a problem, except for formatting floppies. The V20 has a few tricks up it's sleeve, with a few less clock cycles on some instructions, and a Z80 mode to run cpm.

But,the real trick was to put real IBM roms in a clone board and run Xenix. When the clone roms are back in it still booted. Helped a lot to have a 2:1 Rll controller. Xenix was just pollute and delute - system V with some BSD thrown in and a slightly altered portable C complier that was later admitted to be wrong endian.

Did this Board have a FPU socket? Made turbo pascal run much faster. ( The 8087 version we got from the physics lab...) Especially the Hilbert matrix. And FFTs.

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kjs3 2 hours ago | parent | next [-]

Z80 mode to run cpm

8080 mode, not Z80. Did run CP/M, and I used 22nice for probably longer than needed. Unfortunately over time lots of cool software assumed a Z80, sooo...

Xenix was just pollute and delute - system V with some BSD thrown in

Which Xenix? It was originally V7 based, and 'upgraded' to System III around version 3. I forget what it looked like between version 3 and version 5.x, where it became System V based (+ stuff).

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a day ago | parent | prev | next [-]

[deleted]

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iberator a day ago | parent | prev [-]

Why original IBM BIOS was requried for Xenix?!

	▲	ForOldHack 19 hours ago \| parent \| next [-]
		The Roms it came with did not work, also the disks had to have perfect media. Everything bad to be formatted beforehand. So, I got IBM ROMS and it worked, then got some other roms so the keyboard speed switch would work, while the IBM ROMS were installed there was a simple program that would kick up the speed, and turn wait states off. It was slightly faster than a 6mhz AT for DOS and we did not have Xenix 286. Got me through K&R and passed the class, but do useful work? No.
	▲	ForOldHack 19 hours ago \| parent \| prev [-]
		We found out after the third try, that both the IBM and one of the clone BIOSes would run the install, and all of them would boot. ( And an OMTI Rll controller, supported... Dual hard disks too. ) I needed an assembly language program to much the speed up to 10mhz, and it still ran fine, right up to the 'make nethack' then 4 hours later...beeeep beeeep beep. OS not found. We never figured out weather it was a out of memory error or a temp file error ... But the OS was gone.