I’ve spent some time debugging the new KIM Multifunction board this week. These are a couple shots of it on the bench. One chip was piggybacked onto another and a few jumpers added here and there:
This is taken directly overhead, showing the two new motherboard pieces and the multifunction board plugged into the first slot:
As of right now (1/21/2017 evening), everything on the new board works except for the EEPROM. It decodes fine, but the bus transceiver isn’t driving the data bus. The updates to fix the problem were made on the schematic, so tomorrow morning there will be a few more cuts and jumpers. It looks like no additional parts will be needed but the circuit design is enough that I don’t want to sell these with so many cuts and jumpers, and will do a second spin.
Corsham Tech plans on attending/displaying at the following shows in 2017:
- April 1-2, VCF East in NJ
- Late April, VCF SE in GA
- September, VCF MW near Chicago
If you think we should be at other shows, let me know!
These are the three new KIM-1 accessories I’ve been working on. None are for sale yet, as these are the raw boards that arrived in the last couple of days and need to be tested/debugged.
First, there was never a true standard for KIM motherboards. MOS Technology had the KIM-4 but they were never very common, and other companies such as MTU developed their own. None of them were standards except for the boards made by that manufacturer, so a board designed for the KIM-4 did not plug into an MTU motherboard.
A customer asked for a new board that could plug into a home-made motherboard he purchased along with a complete KIM system. His other boards were by MTU so my assumption is that the motherboard was more-or-less compatible with the MTU mobo (short for motherboard). Sure, I could adapt some of my existing designs to the new board profile but had no way to test it given not having a mobo. Well, necessity is the mother of invention, so I created two simple boards that extend the KIM-1’s Application and Expansion buses to four more connectors. The rev 1 boards are good except for an error where the silkscreen wasn’t printed, so the corporate logo is fine, but none of the connections are labeled and there are no indications what the boards are. The one on the left is the Expansion mobo while the right one is the Application version. They work (and will be sold) as a pair:
The connectors are for power and the LED simply indicates when +5 is applied. The Expansion board allows +12 and +7.5 to be connected as well, as this was an MTU extension.
The other board is the “KIM-1 Multifunction” and is basically a combination of our existing I/O board and the 60K RAM/EPROM board:
It has all the same basic features as those two boards:
- RS-232 conversion
- 60K RAM
- 8K EEPROM
- Connectors for tape recorder
- Header for accessing the KIM I/O, which can be plugged into our SD card system
All of that logic was simply combined from existing boards, but this has a couple new things:
- Expansion area – add your own logic
- Bus signals are all buffered – needed for when more boards are plugged into the mobo
- Can take +5 from the mobo or use the 7.5 volt regulator on-board
And I just noticed an engineering tool that was left on the final artwork: notice the two horizontal lines at the top and bottom of the board right in the middle. This board prints onto two sheets of paper for desk checking but I had to be sure the spacing between the connectors was exactly right, so I added two lines of exactly 1″ length. The two sheets of paper got overlaid and those two lines measured, pages adjusted so they were 1″, then taped together. I’ll remove them for rev 2 😉
Assembled boards should be available around the end of January 2017.