I have been sort of dumpster diving in the storage rooms in my university and found 3 huge ISA boards from some sort of very very old video surveillance project, and they are covered with what appears to be 128Kb 8 bits RAM's in DIP format, but I cant locate a datasheet for the chip, if someone knows of a datasheet for this ram's or for a pin-compatible ones, just leave comment here.
A general photo:
And a close up to one of the supposed ram chips:
I don't the make on these (MT), but I believe they are the same as these parts
http://pdf1.alldatasheet.com/datasheet-pdf/view/126292/AUSTIN/AS5C1008-25.html
128K x 8 25nS access times SRAM.
If you could spare a couple I wouldn't mind having them for some future project.
I have also asked the same in AvrFreaks and for some stupid reason I never found the datasheet for this chips after some hours of searching, and now they just pop in every datasheet site that I know, maybe I mis-read some letter and I wasnt searching with the correct part name.
I would not mind sparing a few of then, I dont really know what to do with them at all!
Ideas about some uses?
Got any part number/model number/etc on that board? It looks like it might be a "nice" (for the time?) graphics card of some sort; maybe an ISA 3D accelerator (OpenGL, maybe). I might be willing to buy the entire board, depending on what it is.
I would not mind sparing a few of then, I dont really know what to do with them at all!
Ideas about some uses?
They are nice ram chips, but not too arduino friendly as they take a lot of pins to drive the address and data lines. I guess you could use serial shift registers to supply address and data but then you have quite a few components. I'm sure there are project that could use those chips to good effect but not necessarily an arduino project, at least that's my first impression. I guess a arduino mega board could utilize them as it has the pins and internal hardware interface to utilize these kinds of chips.
Lefty
It looks like it might be a "nice" (for the time?) graphics card
How "nice" can it be, having an ISA bus and 2.25MB of RAM ?
These would be great parts for storing all kinds of info that you wanted to read & write quickly.
Unfortunately you need 28 control lines to access all of it, 17 address, 8 data, 3 control lines.
So stock up on shift registers for direct control of the address lines, or a 17 bit address counter to clock up & down (or more, if want to access more chips).
Clock to create next address, shift in/out the data, etc.
Serial SRAMs do the same kind of thing.
If you had sound sampled at 32Kwords/second (for 16KHzbandwidth), then you could have these set up as 128K x 16 and play back 4 seconds of sound per pair of chips.
Or hook up with an A/D converter and use as a pretty fast digital storage scope. Setup with logic for autosampling once triggered.
I have an Atmega644, I will try to use its external memory interface and do some compiler tricks so the avr can use this external ram as normal ram, should be nice to run the Elm-chan FFT with 12 bits data from an external ADC and perform 1024 points FFT's!
The boards are from an old video surveillance project, thats what is printed in one corner in portuguese:
They seem to be some sort of display drivers, because they have an rgb adc(and not dac as I tough ):
And a 32 bits DSP chip, and the 74ls logic chips are almost all 8bits bi-direccional buffer with 3 state outputs:
Maybe they where in fact some sort of university brew graphic cards, as each card as two VGA connectors, its an ADC so this might be an interface card between some cameras and a computer.
and do some compiler tricks so the avr can use this external ram as normal ram
I recall asking maybe a year ago if the gcc compiler could be made to utilize external ram, but I don't recall getting a positive answer to that question. Both arduino mega boards can interface with external ram, but not sure about the software side.
Lefty
There are some tutorials about that, I think the change is minimal, we only need to tell to gcc that we have external ram and how much we have so it will automatically calculate the new address's for the stack so we can use the new added ram.
I dont use the Arduino IDE but ratter AvrStudio, but it seems easy to do..
retrolefty:
and do some compiler tricks so the avr can use this external ram as normal ram
I recall asking maybe a year ago if the gcc compiler could be made to utilize external ram, but I don't recall getting a positive answer to that question. Both arduino mega boards can interface with external ram, but not sure about the software side.
Lefty
See this:
And then the page to were that page links.
So where is the main board? This board seems to slide in a slot on a main board. I'm interested in the CPU on the main board for some possible trade. The period is around pentium 
I just found this, and a lot of hardware LPT keys for some old VHDL compiler, and a truck load of Tektronix oscilloscopes, but I cant bring them home, a beautifull HP 32 channels logic analyzer that is brand new also cant bring it 
I just found this, and a lot of hardware LPT keys for some old VHDL compiler, and a truck load of Tektronix oscilloscopes, but I cant bring them home, a beautifull HP 32 channels logic analyzer that is brand new also cant bring it
Why can't you take them home?
Because they might be needed to put in some lab, the last year all the analog oscilloscopes where exchanged by new DSO's, but the old ones are all stored away as a backup.
But the university gives away computers and old crt's when they buy new lcd's.
In part I understand, as there are a lot of students that threat the lab equipment in a pretty rough way so the old equipment is stored as a backup.
Yeah - Schools and Universities can be great places to get stuff from but often they're not allowed to give it away (so it goes to electronics recycling - which is dubious at the best of times - or landfill)
