Welcome to Adrian's Digital Basement. I love old computers! If you do too, this channel is for you! This channel is just a result of my hobby, so please be kind when my production quality doesn't stand up to those of other full time content producers.
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Actually, X1 caps are rated for higher peak voltages than X2, so you should keep this in mind when replacing X1 with X2. You can always replace X2 with X1, though. It's similar for Y caps.
The pixel art thing? It was something a fan at VCF Midwest gave me last year. I talk about it and his webshop in this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-De5ufcDueRU.html
Sinclair of ZX81 and Spectrum fame did a small TV like this, called the TV80. Someone on RU-vid has shown it off, working but not as the UK as no broadcast analogue signals any more. Historical interest only really.
I never knew they made an MFM emulator. How can a modern machine keep up with that blazing 85ms access time. 43 years and mine is still chugging along. Use stacker so there is less data transferring, the cpu can unpack it faster.
you can use losetup to create loop devices from files. It will accept an offset into a file. The mount command can even passthrough the offset parameter to losetup
Ibe got 10 sticks of 256mb rdram rambus sticks. 6 ecc and 4 non ecc. Ive got them listed on ebay atm. If they do not sell I was thinking about sending them to you at no cost. If you're interested that is. Ill let you know if they don't sell. I'd rather see them used rather than sit....
At this point it is looking for whatever you type on disk or tape. You just have to give it something to boot from, either the kernel or a utility program. The boot PROM fully understands the UNIX file system, think of it as GRUB in ROM.
You can test whether you need a null modem by measuring which pin is the TX on a piece of equipment. That pin will be driven with whatever positive voltage is used. This works regardless of logic level outputs (1.8-5V) or RS-232 levels (8-15V).
Really loving this series. I have been in the oil and gas industry all my life. In my 20’s I was a unix admin for Sun and SGI for a US energy contractor. I had such fun playing with the hardware, reinstalling OS adding memory. It brought back so many great memories. Thank you. It’s unfortunate how they were ditched for PC architecture almost over night. However, for at least a few years we all had an old Sun or SGI box sitting under our desks switched off just in case we had to revert. All the best Alex.
Hello, thank you for this video. I would like to have more information about the type of card reader that you installed: is better CF card reader or SD one? What about max storage capability? Is the installation process of the new SD/CF drive straightforward or is it somehow tricky? Thanx
Hey, Adrian...see you at VCFSW! And lots of people are comparing your video on this machine to "Forgotten Machines"...so I love the crossover! Thank you!
My dad had an Atari 800 with a couple of disk drives and a lot of other accessories. Full 48KB of RAM too. Now he bought it used from a yard sale around 1985 so it was already a bit out of date but I loved messing with it. 90% of it's usage was to play games of course.
The price on Aliexpress currently shows $16 for me here in the US but prices on there are weird and will go up a lot after you buy one item then check again later.
At 53:57, where the boot commands which reside in the boot ROM is dumped, we can see that these commands look very Unix like, but my guess is they are actually not true Unix commands, in the sense that they are running natively without an operating system, (which has a separate user space and kernel space dividing hardware access privileges). They look to be available commands to diagnose the file system, do formatting and repairs to the file system ("format.pt" and "fsck.pt"), prior to booting Unix SysV. The names of the command seem to have the device extension, i.e. "mkfs.pt" for primary tape. This either indicates which device the mkfs ("make file system") command applies to, or perhaps, which device the command needs to execute from. The full specification (e.g "mkfs.pt(,4)") could be referring to a priority level, or the SCSI bus id, but id's above 7 don't make sense, unless the value applies to two different SCSI busses?. Typing the full command with the extension may be required, i.e. "unix.pt(,2)" or "sys5.pt(,2)" are likely the commands to begin booting Unix, from tape. I would try typing "help.pt" and "help.pt(,)" to see if anything executes differently to "help"? Obviously exercise caution running "mkfs.pt(,4)", "dd.pt(,13)", "format.pt(,3)" as they can modify the device. Try "ls.pt(,14)" once the drive is connected? Also, try "help.pd" and "help.pd(,)" to refer to the disk drive? Just some Unixen oriented suggestions, no actual experience with Plexus machines.
Would be tricky if they used tape to store a lot of utilities for bootloading. Not sure why it is not trying to use disk, it clearly tries, but fails. Maybe this adapter for SCSI has some issue. Also, a lot of weird decision in this computer. Like huge moterhboard, where splitting serial, front panel, and IO processor on own board would definitively make things easier and cheaper. The non-standard serial pinout, also very dubious.
Look, I don't know how I got here, or why I have been captivated by some giganto unix box from the 80's, but I'm going to need to see the rest of this NOW!.
