Hi Guys,
Well, I have to say this is the first time I've ever joined/replied to any online forum, but I felt the need to contribute. Every once in a while I type "Powertran Cortex" into Google to see what shows up and this time I found this thread!
I own two of these great machines, both fitted with the disk interface hardware. I have one here in the States, and one at my parent's house back in the UK. I also built a third one from a kit (the Cortex II - same internals but different case to look like a BBC Micro) for my best friend but that one is no more (but he's still my best friend!).
I know a lot about their workings etc. Your interest seems mostly in the disk interface and its use. It uses the TMS9909 Disk Controller and the TMS9911 DMA. The ROM (Cortex Basic) had a command called BOOT. This reads the first sector on the disk and executes it, which subsequently loads the remainder of the Disk Operating System from the disk.
There was a company called Marinchip Systems based out in California. They had various TMS9900 systems and a couple of Operating Systems. One was called MDEX (Marinchip Disk EXecutive) and NOS (Network Operating System). One of the key people there was John Walker and he initially created the foundation of AutoCAD on this platform! Micro Processor Engineering (MPE (or uPE)) migrated MDEX to the Cortex platform and that was its first 'DOS'.
The big problem was that MDEX was a completely different OS/environment to Cortex Basic. It was really a text-based/VT100 based OS, so none of the graphics were available. You couldn't run anything you had developed under Cortex Basic and the commands were very simple - kinda CPM ish. It pretty much made the Cortex HW emulate a single VT100 and that was it. It had a bunch of apps you could buy (I'm talking loads of money and I was 14!) such as QBASIC (compiler) and SPL (Systems Programming Language kinda like C) and some others.
A couple of years later, a guy called Neil Quarmby, who worked for TI in the UK (and I believe created the Cortex Basic release of TI Power Basic) released CDOS (Cortex Disk Operating System) and this was the cats ass! It was the disk extension to Cortex Basic. Turn the machine on, type BOOT and you were away! Everything as it was + a disk filing system - awesome! You chucked out the cassette player that night!
I have MDEX and CDOS on disks and they work. I have also written a Cortex emulator under Borland C++ Builder 5 (yeah I know that's old too) and have some disk images converted to PC files so that you can BOOT them. I also have just about every MDEX + APP manual. My biggest problem is that I'm extremely busy in my day to day stuff and I was somewhat reluctant to write this but since you have a shared passion, I couldn't resist. I would like to help revive this machine but need patience.
Hope this is useful,
Dave.
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