Back in college physics I'da never thought owning a CBL would be in my future!

Working on #Z80 Reverse-Engineering And Hacking Adventures, I had a weird epiphany... Ordering some chip sockets to solder in to the empty ROM and RAM slots, I came across ISA prototyping boards for a price I couldn't refuse. I'd had my eyes on them for years, always way out of my price range... and here their price-per-hole is highly competitive with regular ol' protoboards. It seemed wrong, but, lacking other protoboards, I started thinking about using the ISA board as just a regular-ol protoboard for a Z80 riser-board, where-on I could try out some of the crazy ideas I had in this TI-86ing project for things like memory paging, display refreshing, and such. But I really couldn't get over the nagging feeling about using that long-sought ISA protoboard for something completely unrelated to ISA.

...

A few days later I woke to an epiphany. A huge part of the reason I did #Improbable AVR -> 8088 substitution for PC/XT was for the sake of using and making [especially: weird] ISA cards. Here I'm planning to stick a Z80 processor, and various weird hacks, on an ISA card... I mean, wire that thing up to the edge-connector [too], dummy!

So then, I started thinking about it even more, and it occurred to me, I could quite-literally use the Z80, on that ISA card  to be the main CPU in the system, by basically putting the bus in permanent DMA mode. Now we have an "Improbable Z80->8088 substitution for PC/XT"... or, really, any PC with ISA slots. Or... backplanes... or... heck, apparently there are plenty of ISA riser-cards from various weird old servers and computers... wouldn't even need to halt the main CPU for DMA, just don't plug the riser into the motherboard.

Z80 with VGA and a soundblaster, yo!

But, again, I really dig *weird* stuff, I mean VGA is great, but there must be some weird old ISA cards that no one can even figure out what they are, nevermind find drivers for, for pretty cheap, right?

So I started searching... and sure-enough I found some from what appear to be industrial systems, and others from test-equipment... And knowing a bit about what to look for, it's not too difficult to recognize whether some weird old card might be within my means to program without any documentation... Or, at the very least, have components I could be glad to scavenge.

So I found one I couldn't pass up for $9... This one has four high quality 24-bit ADCs that can sample at up to nearly 400KS/s. No small shakes, and every chip on the board is *very* well documented. But "the seller doesn't ship to P.O. boxes." So, through a bit of aggravation, I'm sure, on the seller's part, we found an arrangement that'd work... For nine measly bucks, including shipping. I felt kinda bad putting them though all that. So, well, I figured I'd see about other things they were selling, to make the extra trip to their less-preferred shipping depot worth their while... And, well, there were many other things under ten bux that I was interested in, but one really caught my eye...

A Texas Instruments "Calculator-Based Laboratory" to be interfaced to a TI-Calc... Which, as you may've gathered, I have learned a thing or two about.

This thing, too, is *very* well-documented, down to pinouts and configuration,, and even instructions for teachers to run long-term logging on field-trips off lantern batteries! And, again, every chip inside is well-documented, too. The only hidden part being whatever the microcontroller's ROM contains (and who knows, it may be dumpable).

But, before I even bothered to look up documentation, I just plopped in some batteries and turned it on... didn't even hook it up to a calculator... and... This blasted thing turns-on as a multimeter! No kidding... I had been debating investing in a couple more cheap multimeters, actually... For e.g. trying to monitor current and voltage simultaneously while charging/discharging old Li-Ions. I'd found cheapos for about $6...

For $10 and attached to a $7 Goodwill-find, I can do logging of multiple channels over hours, and graphing, and more. Heh!

This could be quite the handy piece of "lab equipment"... the sorta thing, yes, I *could* do with an AVR... and plausibly far "better" (more memory, SD-card, higher sample rate, whatnot) but, this already has the screen, keyboard, UI, analog front-end (which I'm not so great at), and more already done... and I've yet to get around to AVRing it... So... Awesome!

Heh!

Having looked up pinouts and found extensive documentation, It goes beyond all those piddly details... here's a system you can reconfigure dramatically in the palm of your hand... Have twenty different programs ready to go at your fingertips... No compy required. Plausibly combined with my TI-86 hacks (like flash-memory) it could be even better... Long logging expeditions could contain many more datapoints by transferring to the calc in realishtime, Min, Max, Average for each regular sample (say once every ten minutes)...

I've plenty of ideas how to make use of it. Logging the charge/discharge of my car battery, for instance. Determining A-h ratings of old laptop batteries. And some weirder "logging" ideas: e.g. the van gets *really hot* when the sun shines on it. Yet, the temperature at the floor feels *easily* ten degrees cooler. Opening the window, it feels ten degrees cooler than that. Opening the door, even cooler. Sometimes I'm near certain it's thirty degrees hotter in here than outside! Log That! Alongside a video, maybe. Or weird issues with the engine that can only be experienced while on the road... Can't be writing notes while accelerating... This thing does multiple channels, after all.

Anyhow, Ten Bux... I'm kinda "stoked".

Oh, and the ISA card looks pretty awesome. Only thing is an 8751 microcontroller "black box". But I think I managed to read its ROM, and it is a *very* small program that may merely be used to convert the ADCs' SPI to ISA.

I also came across another ISA card for even cheaper that I couldn't refuse, either. I'm guessing it was a power/frontpanel I/O board for an industrial backplane-computer of the sort that has the CPU on a card (kinda like I'm thinking to do with the Z80)... It's got a connector at the back for *outputting* 5V and 12V, with voltage-sense inputs on both ground and power. (but why would it send power *out* through the backpanel bracket?) Two DC-DC converters, anyhow, with their Vin, as well, at the bracket. But it also has regular ol' 7400-series, all the way to the ISA connector, for a whole bunch of other stuff, including TTL-I/O and LED drivers... So, TTL logic... figuring out how to control those I/O shouldn't be difficult, right?

Heh, who knows.... Z80 ISA computer, anyone?