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L/F Technologies serial parallel card

E

Endersending

Experienced Member
Joined
Mar 14, 2023
Messages
119
Location
Walker, Minnesota
Hello VCF,
I purchased a s-100 serial card with no documentation on how to use it.
I was wondering if someone knew where some example code for something similar to this I could look at and learn how to control it.
The board is a L/F Techonogies SPIO board. model A1250 I think. It looks to me that this card has 6 serial ports and 1 parallel port. and the address is currently set to 11100000. Although it is not shown in the picture, jumper JB has a silk screen with 0 on the right and 1 on the left, so A5,A6,A7 are 1's.
I am assuming this is the base address of the card, and everything is accessed in address ranges above the base address.
If someone know of a good resource to read about how a board like this works or even better the manual or documentation for this actual board would be awesome.
I also purchased a floppy controller with eprom that I plan to use with this serial card but that is a different problem in another thread I posted.
Thanks for the help.
lftech.png
 
There may not be any documentation that exists for this L/F Technologies board - my impression is that it was only sold as part of complete systems manufactured by that company. Some information about the company and its other products can be found on Herb Johnson's web site at this page:

You can learn a bit more about the operation of this board by looking at the data sheet for the Intel 82530 "serial communications controller" used for the serial channels. I am not aware of any other S100 system that made use of the 82530. I think Intel primarily marketed this chip for use in "advanced" systems based on the x86 processor.
 
I have decided to put this card back on ebay. I purchased a Cromemco TUART board which has plenty of documentation.
Thanks for the help and myabe someday someone will get the card working.
 
This is an area where problems are becoming increasingly apparent. I have noticed over many decades now, that computer boards get separated from their manufacturer documentation and it vanishes. Probably what happens is the boards get fitted to the computer and the documents put in a drawer later to be thrown away. The original documents now may even be rarer than the boards of any particular type. It reminds me of the scene in the remake of the Time Machine movie with Guy Pearce, where in one version of the future, he put the design for the machine in a drawer and the machine was never built. No doubt later they were thrown away.

Another thing, is that when documents have been scanned into a .pdf and put on the net, the copies are often poor and there can be missing pages. This happened for the S-100 Matrox video card and 1/2 of the schematic was missing from the online .pdf because that page got missed in the scan.

The absence of the paperwork on a board could render it unusable without a lot of experimentation and if it had a fault, difficult to fix without the schematic. Though, at least with enough patience, the schematic can be traced out and re-created.

I hope the information on this board can be found and also the contents of the OTP Rom on it ideally would be dumped (I think that probably is one with the white sticker on it)
 
Hugo Holden said:
I hope the information on this board can be found and also the contents of the OTP Rom on it ideally would be dumped (I think that probably is one with the white sticker on it)
Click to expand...
Likely the IC with the white sticker on it is a PAL used in the board's address decoding logic.
 
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