Hi John, thanks for the feedback, I will add pullups to P6, P7 on U6 I also will use the second MMV as suggested ( I didnt think of doing that ) Jumper block K3 sets the input voltage to the second regulator depending on if a 7812 regulator or a LM3940 (3.3v) regulator is used, K4 sets the LED bias current depending on if we have a 12v or 3.3v output voltage. It has also ocurred to me to bring the INT* signal to connector P7 as it might be needed for some projects I will make changes over the weekend and report back regards David Fry
On Wednesday, May 21, 2014 11:01:55 PM UTC+1, David Fry wrote: > Hi All, > > I like a number of others on the forum have over the last couple of weeks > been starting to learn how to use the KiCad workflow process, I just though > it might be interesting to share what I have been doing with the program > and get some feedback from other members on the forum. > > I have been developing another S-100 prototyping board for my own > purposes, yes I realise that there are at least 3 others currently > available, two of which are dedicated to providing as much prototyping area > as possible. This proto board is aimed specifically at I/O port addressed > projects and takes a different approach in supplying pre-wired all the > necessary S-100 port decode logic and data line buffers/control and > presenting all the necessary signals to 3 SIL connectors close to the > prototyping area. I am not taking any credit for the design as it is taken > directly from the S-100 IDE board I'm just re-cycling the circuitry to make > port addressed prototype projects quicker to produce. > > The board has positions for two voltage regulators, one for the 5v rail, > the other can be jumpered for either 12v or 3.3v > Regulators have been positioned to allow heatsinks to be fitted as > required. > Both supply rails and gnd connections run along left hand edge of proto > area to facilitate horizontal orientation bussed supply rails > Port addressing can be jumpered for 8 or 16 bit I/O port addresses > Port address jumpering for a 2, 4, or 8 I/O port window > An addition of a Monostable Multivibrator to drive the Board Enable LED > Lower 8 bits of address bus buffered for allow further decoding > All signals brought to 3 SIL connectors along edge of prototype area > > My question to all you all is, have I missed anything out with regard to > features/signals needed for port I/O based projects ? > John, I would be particularly interested in your input > > I have attached the schematic and a board layout to this post, If there is > sufficient interest in the community for this board then I am quite happy > (once ironed out) to hand it over to the guys doing pcb production. > > Regards > > David Fry > -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
