wow! celebrity! I' just off out now, but I'll be adding my questions to the list!
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wow! celebrity! I' just off out now, but I'll be adding my questions to the list!
"Don't it always seem to go
That you don't know what you’ve got ‘til it’s gone" (BANG)
Do you possibly have a datasheet/the compete function pin-out for the 74LS2001 used on the E-Bus interface? Information on that one seems to be completely lacking on the net or anywhere else. I haven't even been able to find a source for the E-Bus System Design Handbook (MP402) from TI. One source in Poland apparently still has some of the chips, but I haven't been able to confirm that yet. If they do have any, they are likely the last source on Earth with any quantities of them. . .
And thank you for dropping in here--information on the Cortex is always useful, and any data you can provide on its background is invaluable! Right now, the sum of what I have are the articles from ETI that appeared in NOV 1982, DEC 1982, JAN 1983, FEB 1983, JUN 1984, AUG 1984, and SEP 1985. I also have the construction manual from Powertran (for the minimal setup without any options) and the POWER BASIC manual (which I converted to an editable PDF from a series of GIF images). Any additional documentation (with or without the associated software) would be greatly appreciated.
I'm in the process of trying to build the options into my Cortex. I have acquired a number of the TMS9909 and TMS9911 ICs to work on the disk system, but the E-Bus has been a hard nut to crack into. With enough data, I may have to try and reverse-engineer it in VHDL and roll my own. . .
I do have the E-Bus patent description with the internal logic and timing, but not where the signaling should go (some of it will become obvious from tracing signals on the Cortex, but not all--as that is my next planned attack vector).
TMS9995, one of your earlier comments reminded me of something I haven't thought of in ages. Marinchip Systems also built a TMS9900 board for the S-100 bus. I was looking for one of those for a long time but never did encounter anyone who'd ever heard of it or them. Thanks for the reminder. . .one more vintage 9900-family system for me to track down.![]()
Hi Tony, thanks for stopping by! I would love to hear what you know about this machine. Most of my knowledge is from the User Group that was around at the time, plus the usual 'reverse engineering' that goes on whilst you got your head burried in the datasheets! It would certainly be refreshing to get some insight from someone who was on the inside.
I don't remember anything about the LS2001 off the top of my head but I'll have a look around to see what I can find, it is quite possible that it never actually existed.
I do however have a copy of the e-bus system design book (MP402) in my hand at the moment, it's about 1cm thick so a lot of copying.
We'll see what Tony has to say, but it is my understanding that the 74LS2001 was essentially just a made up name for a gate array to control the E-Bus arbitration and timing. I have never known of one to exist. I guess the intent was to develop all these intelligent multi-processor peripherals for the Cortex, so a sophisticated expansion bus was added to the design but it was never really utilised in that way. So, there was a simple circuit built onto a header board that plugged into the infamous U89 socket (I have the details) that basically allowed the Cortex to drive the E-Bus as a simple expansion bus, without permanently locking up waiting for a Bus Grant signal.
Yeah, that was the system MDEX and the first version of AutoCAD was designed on/for. In one of my first comments, I didn't mean to imply the Cortex was used for this purpose.
I have been scanning for over a week now and have been encountering some quality issues etc. using the cheap scanner. However, my better half has a big networked Ricoh copier/scanner at her office. I have, er, given it a 'trial run' late at night and it does a very good job scanning to my laptop, so I am re-doing everything which will take some time, but will be worth it in the end.
So far I have done the entire ROM Source Listing (582 pages!), MDEX Assembler, MDEX System Generation, MDEX Debug and CDOS 1.1.
Also, the emulator is about ready for deployment. I'm just finishing up emulating the 9909 Format command. I don't pretend to be an award winning Windows programmer, so please excuse it's presentation. It works very well, but it's kind of light on the bells and whistles...
Ebus cards definitely existed, the bus was one that TI used for a range of eurocard sized boards and the cortex just used that bus as a means of expansion. All of the cards I remember had discrete logic for the bus arbitration & control, I think the LS2001 was a number allocated for a gate array that never came to fruition.
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