ISA Voltage Regulator Cards? 20
stripey357 asks: "I'm trying to install a Dialogic Gammafax card in Pentium-based SCO unix box, and I've run into a problem. The power supply for this box doesn't supply -5v to the ISA, and that's the voltage the Gammafax wants. Do they still make ISA voltage regulator cards that can reg -12v down to -5v, or would it be easier to replace the power supply?"
Possible solution... (Score:3, Informative)
If it is just that card that needs it, and you know which pin it is on the ISA card, you might be able to do it yourself, with a little work:
The power supply should have a -12 volt line (or even a -5V line, which is easier) - find the pin(s) on the ISA card that need the voltage, trace each one back to a solder pad (or you might have to scrape the trace). Cut the trace with an xacto knife to keep voltage flowing into the motherboard (unless you know that it is routed properly - better safe than sorry). If you need to scrape the trace, do it with the knife as well. Apply some solder, add the wires you need, bring 'em together at one point, and hook up the -5V if you have it from the PS, or if you only have -12V, used a -5V regulator (sorta like the 7805, which is a +5V regulator - they make the opposite, can't remember the part number).
Of course, this invalidates all warranties, and it could cause other problems - it is a hack, plain and simple, I am just offering it to you as a possibility and learning advice - don't blame me if your motherboard/fax card/power supply blows up...
I hope this helps... Good luck!
If there's no -5V, there's probably no -12V, too. (Score:1)
If you're really cheap, some old ethernet cards have isolated 5V to 9V convertors in them. Use one of them and a 7805 to get an isolated 5volts. Tie the isolated +5V to system ground, and the ground from the 5volt supply will be at -5V.
Re:If there's no -5V, there's probably no -12V, to (Score:1)
Don't solder directly to the card (Score:1)
ISA is a bus - all the pins on all the slots are wired to each other, straight across. Go to an electronics shop, get an ISA perfboard card, put the regulator on that, and have it supply power to the other slots.
That way, if it doesn't work, and there is no smoke discoloration, you can hide your tracks if you need to send it back for warranty repair :)
Re:Don't solder directly to the card (Score:2)
However, I do like your solution - much sneakier in case something goes wrong...
Re:Don't solder directly to the card (Score:2)
Re:hrm (Score:2)
(when it does work, it's a beautiful thing, though. one of my favorite things we did with it was run a logistics package; the software vendor didn't realize it was a linux box, but they did call us up when they modem'd in and 'ps' didn't work (SCO uses a SysV ps, the one on there was BSD-only, since updated).)
iBCS also has a bit of a problem with some security setups. all that is immaterial, however, because for all intents and purposes, SCO usually Just Works.
Fax Cards (Score:1)
http://www.itox.com/pages/products/Mothers/Itox
The board gives me 5 ISA Slots and 2 PCI Slots in a ATX chassis, and has been extremely reliable. Replacing the motherboard might be the easiest solution. If you are able to, you could change the card, the CPi400-LSI may work.
7905 - 3-Terminal Negative Voltage Regulator (Score:2, Informative)
Do they still make ISA voltage regulator cards that can reg -12v down to -5v?
You're looking for a 7905 regulator, provided the card does not require more than 1A. These regulators are quite common LSI devices used in hobbyist electronics, they can be found at Radio Shack. Several firms manufacturer 7905's, here are some datasheets:Re:7905 - 3-Terminal Negative Voltage Regulator (Score:2)
Where is the deviation from standard? (Score:2)
ISA Extenders (Score:1)
My second idea is, and this is a long shot, I know that companies like az-com [az-com.com] and catalyst [catalyst-ent.com] make ISA active extenders which you can use for hot swapping cards, but you can also supply external power and I think regulated power, from which voltages I wasn't able to find out. I can't remember if the ISA ones did have regulators, I know the PCI ones had regulators for using 3.3v cards on 5v etc... The down-fall of these is first of all, the card will no longer fit in the case and secondly they cost around $200-$300...well at least they used to, maybe they're not in demand as much anymore.
Hope that helps..
Not the best solution...but... (Score:1)