On Jan 15 2014 1:20 AM, Gene Heskett wrote: > On Wednesday 15 January 2014 02:35:44 EBo did opine: > >> On Jan 14 2014 9:14 PM, Gene Heskett wrote: >> > On Tuesday 14 January 2014 23:11:44 andy pugh did opine: >> >> On 15 January 2014 02:13, Dave Cole <[email protected]> >> wrote: >> >> > Assembler .. yep I remember doing some of that on 6800 Micros.. >> >> >> >> Very >> >> >> >> > tedious. >> >> >> >> Tedious? Ha! I used to _dream_ of an assembler, I wrote machine >> code >> >> in raw hex, from a paper list of mnemonics! >> >> (on the Z80) >> > >> > Tedious? Just a bit. I have on the shelf above me, paper and >> audio >> > cart >> > copies of some code I wrote without an assembler, in 1978 for an >> RCA >> > 1802. >> > It worked well, and was still in use 15 years later the last time >> I >> > checked. Like you, I did the same thing on a Z-80 a year later. >> >> Gene, thanks for the stroll down amnesia lane... Back around the >> same >> time I was hired to write the OS for a monitoring system for a >> geothermal test well that used an RC >> Many years later (just prior to Y2K)A 1802! The funding org was so >> tight that they could not afford to purchase one of the only >> assemblers >> for the thing. So the entire OS, drivers, etc., was all written in >> hex... >> >> One of my friends that worked with that engineer years later adapted >> the code and project for another purpose. In the mid 80's we got to >> talking and I boasted that I could now write him a macro assembler >> for >> him in 24 hours (he had to buy me a case of coak-a-cola as pay. >> Well I >> missed the 24h deadline, but had it working within 36h... Now step >> forward to 1999. My buddy check his code for Y2K issues and found >> one. >> He needed to go back to that ancient code (and the completely hacked >> together macro assembler I wrote over the course of a day and a >> half), >> he dusted off the tarball, recompiled the assembler in a more modern >> C >> compiler, it compiled with a few warnings (but nothing sever), made >> the >> change to his code, ran it through the assembler, and a day or two >> later >> had the Y2K bug patched... As I recall he bought be another case of >> coke ;-) >> >> BTW, I loved that chip. You could do a multi-thread context switch >> in >> a single atomic operation. It was WAY ahead of its time... > > In a sense it was. Its Achilles heel was that everything in and out > of it > had to go thru acca or accb, then moved to/from the register it was > to/from. A full machine cycle was several microseconds. But despite > that, > it did manage to get my job done, which was run a tape machine with > tight > timing control, backwards and forwards, doing audio and video inserts > to > lay a new digitally generated academy leader on a commercial, and lay > the > cue tones on audio channel 2 to make it work with a Microtime > Automatic > Station Break machine. All dead on the money frame accurate. > > When I got done and it appeared to be working as desired, so I got > curious > as to how long it actually took to do what it needed to do 59.94 > times a > second, all of which started on the falling edge of house vertical > drive > from the sync generator, and had it set a flag bit I could watch on a > scope > when the falling edge of the drive came in, and turned it off as the > last > thing it did before going into the loop to wait for the next pulse. > It was > done, had issued all the commands to the machine, and generated the > video > bytes that would be DMA'd to my 8.8 format 2 digit generator that > made > characters 103 horizontal lines high vertically and about 40 u-s wide > since > we needed to be able to read them from across the control room on a > 5" B&W > monitor. Counted down from 9.9 to 1.9 seconds before the first frame > of > video that was to be switched to air. With all that monkey business > it was > done in the middle of line 19 of each field. Nominally 1200 u-s. I > was the > ACE at KRCR-tv in Redding CA at the time. > > Another interesting chip, somewhat later time frame but still in the > megacycle clock era was what was the TI-9900 in the TI-99/4A. That > thing I > believe had only 2, 16 bit registers and the 16 bit alu. All its > actual > registers were kept in memory! Including its stack and program > counter. A > "context" switch was as simple as pointing the internal register > pointer at > a new image of the registers. It left the preceding procedure > untouched > while it executed a "subroutine", and when the subroutine was done, > the > pointer was reloaded with the base address of the register image it > had > left, and other than the time elapsed, neither process knew of the > other. > > But I think the lack of fast memory kept it out of the speed running > when > some of the other cpu's started cranking up the clocks. That was in > the > era of 350ns dram, at $10 a kilobyte. > > Yeah, memory lane. Its a long winding road that for me stretches > back to > about 1939, on a farm in Madison County IA., where all those bridges > Eastwood and Streep made a movie about were. And I've covered most > of the > country west of the river working, till I came to WV in '84 & decided > to > ride it out, come what may, I had found my "place" at WDTV-tv. The > woof > didn't like WV, left & took the kids a year later, and I wound up > with an > old maid music teacher I finally made legal in '89, so next Dec 2, > we'll > have 25 years in without ever strongly thinking of an Alaskan > Divorce. And > by then I'll be 80.
Gene. Congrats on finding the old maid music teacher, and the past 25 years! Cool projects BTW. EBo -- ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
