I think the "I can't boot the computer" issue when using only SIOA is critical enough that I need to make a new revision of the PCB. Both of these are solved by simply adding two resistors on SIOA: a 470k pull-down on CTS, and a 470k pull-up on RX. Also, when using only SIOB with nothing at SIOA, there's a case of character injection. When using SIOA, with nothing connected to SIOB, it's nearly impossible to get the computer to recognize the SPACE press needed at boot to select console. On the C-revision of the PCB, I have discovered that using only one Serial Port with the other not connected causes usability issues. Brushing aside delays caused by funding, I've decided I need to halt the progress a bit. Unfortunately that's obviously not the case. I had hoped to have the kits available already, to be honest. I've also done quite a bit of evaluations on materials needed for handling/packing/shipping, and there's a bunch of bags and boxes on their way to me currently. The base set of passive components, and the "jellybean parts" have all been ordered, or I already have them in stock. I've also been talking with Steve Cousins about the possibility of a future port of his Small Computer Monitor (SCMonitor), and we are both enthusiastic about that (scmonitor will not be included in kits, at least not at launch). Getting his permission really made me happy. I've received permission from Grant Searle to include his software on ROM in the kits, and also his permission to make available changed code for the parts where I need to make changes. I'm planning on selling the kits though Tindie when I get them, well, kitted up. I have updated my company page over at linc.no/products, and that will be the "home" of the product side of things. I'm most definitely working to get kits of this microcomputer available. Here's an update to those who are following my " homebrew" tag to see if I actually end up making kits available. Steve's SCMon uses the "reserved" address 0x30 as a simple output write port for status during boot, so setting this card's address to 0x30 allows the nice led-scroll to be seen □īased on the schematic below, I will start doing a PCB layout, and make this an official LiNC product as soon as the LiNC80 SBC1 launches proper.ġ4Mar/18 0 Status of the LiNC80 SBC1 mid march 2018 Writing to the selected address sets the output state, and reading the address reads the current values on the buttons/switches. The way the 8-bit comparator is used makes it possible for this card to use any single I/O address in the Z80 I/O address range. This is a simple I/O card that uses a 74LS273 latch to receive and store output data displayed on eight LEDs, a 74LS245 bus tranceiver to "gate" the input switches/buttons as inputs, and a 74LS688 8-bit comparator to do full address decoding of 8 bits. As expected, the card performs exactly what it was designed to do, both when connected directly to the SBC and when connected to a 5-slot Z50Bus backplane. During that time, Steve Cousins and I were talking about his boot-up status output using a standard I/O port, and that it would be nice if I would be able to provide a digital I/O card a short time after launching the kits.Īs I already had my prototype prototyping cards and a bit of time, I designed a card inspired by Spencer's RC2014 Digital I/O card, and assembled it using simple point-to-point wiring. While working towards getting my LiNC80 SBC1 kits ready for sale, I had a little bit of waiting-time to cover. 2May/18 0 Digital I/O card for my Z50Bus computer
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