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View Full Version : An New S-100 Bus Interrupt Controller & Real Time Clock



monahan_z
July 10th, 2010, 04:09 PM
For people interested in building/repairing S-100 systems Andrew at N8VEM and I at 100Computers.com have just completed the construction and testing of an S-100 bus New Interrupt Controller and Real Time Clock Board. If you would like to read about this board please look here:-

http://s100computers.com/My%20System%20Pages/PIC&RTC%20Board/My%20PIC%20Board.htm

There is a growing list of people getting interested in these S-100 systems. We get these bare boards produced in batches (typically $20-40, depending on demand). So if you would like to try this board you need to contact Andrew or I ASAP. It may be some time until the next batch.
:p

billdeg
July 12th, 2010, 04:27 PM
I searched your site but I am not sure so I will ask...do you have a board similar to the Vector Graphics ZCB? The ZCB is a CPU/Prom/I-O board.
Bill

NobodyIsHere
July 13th, 2010, 03:47 AM
Hi Bill! Thanks! No, we do not have an S-100 Z80 CPU board *yet*. The next two boards in build and test will be an equivalent though. I ordered the first round prototype PCBs for the S-100 Z80 CPU and S-100 IO boards. I have no idea when they'll be done but given the complexity of the Z80 CPU board I would expect some updates as it goes and a second round of prototype PCBs is realistic. Expect months before manufactured PCBs are available.

The current boards in build and test are the S-100 bus extender which is basically done awaiting its turn for PCB manufacturing. The S-100 PIC/RTC is also done awaiting PCB manufacturing. Both completed a second round of prototype PCBs and are good to go. The S-100 EPROM board is in its first round of build and test so we'll see how that goes.

The S-100 SMB had some changes from the second round of prototype PCB build and test. The display mezzanines (HP5082-7340, TIL311, and LED bars) are done but the base board had to go through trace route optimization again which seems to be taking forever to complete. The changes didn't seem that extensive but it is a complicated board and they must have disrupted it more than I thought.

My plan is to distribute the S-100 buffered prototyping boards next which should arrive any day now. They just went through a PCB respin and a PCB manufacturing reorder. Next will either be the S-100 bus extender or the S-100 SMB depending on if the latter is ready to go. The other board of the two will follow soon after. Finally the S-100 PIC/RTC and then the S-100 EPROM.

John and I keep working on the S-100 boards and it has been a lot of fun. We keep an eye on the destination of a completely free (speech) and open S-100 design and that is moving ever closer to reality. Its been a pleasure working with John as he is very talented and a skilled designer.

In the last few days we've been focusing on the build and test process so I've been less busy on the PCB schematics and design. In the meantime, I've been working to catch up on the N8VEM ECB projects. We just released the SGC board which was going along fine although there was a minor problem with the AY-3-8910 on the PCB. A quick couple of trace cuts and a jumpers fixed it but it is a bother. Almost none of the legacy ICs like AY-3-8910 are in the KiCAD parts libraries so I made a custom one but with an error. It is easily fixed but will need a PCB respin so the plan is to just keep testing the existing board and shake out the rest of the bugs. The boards seem to work fine though and it is interesting to watch the development with the new board.

A few weeks ago I ran out of the N8VEM ECB SBC PCBs and thought to make a "couple of minor tweaks" which turned into an almost complete redesign of the board. It being the oldest of the ECB boards it had the most accumulated fixes and improvements queued up. Thanks to a lot of help from the builders the new PCB is basically done and in trace route optimization. It is much more complex now so it is taking quite a while to finish. It will have its own build and test phase in the next few weeks.

I ordered a bunch of N8VEM "mini boards" from various builder projects. The PPIDE is a small adapter that lets the SBC drive an IDE device like a hard drive or CF directly from the parallel expansion port. No ECB backplane needed so it should make storage a lot more affordable for new builders. I also ordered the Juha SD PCB which allows the use of SD for CP/M storage but it doesn't use the ECB backplane or the parallel expansion port. It's cable solders directly on to the back of the PCB and uses a custom ROM image for a very low cost expansion option. Its really a neat design so I am looking forward to seeing it out with the builders. I ordered some of those ECB to Z80 CPU shim socket PCBs to hopefully spur some development of adding N8VEM ECB boards to other vintage/home brew systems like Kaypro, SpectraVideo, etc. There are some other minor doodads going on too like PCB reorders.

Finally there has been some development on the N8VEM 6809 stand alone system. One of the builders has been designing and prototyping a 6809 to ECB bus bridge circuit. What's neat about that is now regular ECB boards like VDU, DiskIO, SGC, PropIO, etc can be used with the 6809 host processor and IO mezzanine combination. To help this along, we merged the 6809 ECB bus bridge circuit with a 5 slot backplane to make a new 6809 expansion board. This board stacks on top of the IO mezzanine for a three layer PCB "sandwich" design. Then ECB boards like the VDU and DiskIO plug in vertically on top. The 6809 system is running CUBIX and is working great with the VDU and DiskIO. Test with the SGC are looking good and so this is definitely exciting stuff! The 6809 host processor used to be completely dependent on the Z80 SBC and ECB backplane for even basic IO support but now it has evolved into a completely separate system and independent. You can still plug it into the main system ECB backplane if you want but there really isn't any need for it.

Thanks and have a nice day!

Andrew Lynch

NobodyIsHere
October 21st, 2010, 08:55 AM
For people interested in building/repairing S-100 systems Andrew at N8VEM and I at 100Computers.com have just completed the construction and testing of an S-100 bus New Interrupt Controller and Real Time Clock Board. If you would like to read about this board please look here:-

http://s100computers.com/My%20System%20Pages/PIC&RTC%20Board/My%20PIC%20Board.htm

There is a growing list of people getting interested in these S-100 systems. We get these bare boards produced in batches (typically $20-40, depending on demand). So if you would like to try this board you need to contact Andrew or I ASAP. It may be some time until the next batch.
:p

Hi! The S-100 PIC/RTC boards have arrived. I'll be shipping them to the builders on the waiting list first but I think there will be some left over. If you want one or more please contact me. They are $20 for the PCB only with $3 shipping in the US and $6 elsewhere.

The S-100 PIC/RTC boards are useful on 8080/8085/Z80 systems but are going to be nearly essential on the upcoming S-100 x86 CPU boards next year. x86 operating systems like CP/M-86 and FreeDOS almost require a PIC to operate properly.

Thanks and have a nice day!

Andrew Lynch

MikeS
October 21st, 2010, 10:39 AM
I searched your site but I am not sure so I will ask...do you have a board similar to the Vector Graphics ZCB? The ZCB is a CPU/Prom/I-O board.
BillDon't give up just yet ;-)

NobodyIsHere
October 21st, 2010, 12:51 PM
Hi! Yes, there is an S-100 Z80 CPU board in the works. John finished the second round of prototype build and test. The PCB is grinding away in the trace route optimizer now along with the S-100 68K CPU board.

Hopefully they'll finish before too long and I can order some manufactured PCBs. The S-100 Z80 CPU board is CPU plus onboard EPROM but no RAM or other IO. The RAM and IO can be added with other S-100 boards because there simply was no more room left on the S-100 Z80 CPU board for a UART. The S-100 Z80 CPU board has full IEEE-696 compliance which chews up a large percentage of available board space.

Thanks and have a nice day!

Andrew Lynch

NobodyIsHere
November 4th, 2010, 03:14 AM
Hi! I still have a small number of the S-100 PIC/RTC boards left. These work fine with 8080/Z80 systems and are going to be used heavily by the upcoming x86 boards planned for next year. Please contact me if interested.

Thanks and have a nice day!

Andrew Lynch