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Lee --
I know decidedly unvintage, but you can use an ATMEGA88 as a composite color video chip. I use it on my 6502 SBC. It needs an oscillator (16MHz), two resistors, the chip and an RCA jack (or flying leads to an RCA jack). There are VGA solutions too, using for example the Propeller chip. Take a look at the board from S100Computers. Obviously you can cut a lot out of the design (like decoding and port selection, the LED displays, etc.). Rich -- Rich Cini ?On 7/26/20, 1:31 PM, "Lee Hart" <[email protected] on behalf of leeahart@...> wrote: ajparent1/kb1gmx wrote: > Thump thump.. testing 123 test test... > IS there any life or is it dead? Hi Allison, It's alive; just sleepy. Too many distractions, I guess. Let me see... what have I been doing with the Z80MC lately? 1. The 7-digit LED display has become hard to get. I found a replacement, with green 7-segment LEDs. It's also a surplus part, but I got enough to last a while; so I can keep producing kits for the forseeable future. Physically, it has wire leads instead of pins (they have to be bent slightly to fit the holes in the PCB) and lacks the "steps" in the corners of the old red LED display. That's it in the picture of the Front Panel card on my web page <>. 2. I changed the LED-photoresisor optocoupler (used to control the piezo speaker) to a standard LED-phototransistor part. It added a resistor (and I always fight to minimize parts), but it's a standard part and so easier to get. 3. I made a few improvements to the CPU board: - I flipped the 5v regulator upside down, so its metal tab faces *away* from the PCB; this provides better cooling. - It also made room to add a 6-pin power/serial header (same as on the Front Panel card). Use this header with a USB-serial cable run the CPU board "barefoot" (without any other cards). The plan is to sell the CPU board by itself for half the price, for any little Z-duino projects you may have. - I added jumper options to put BUSAK and BUSRQ on the bus in case they're needed. but there's an error in the silkscreen; the HALT and BUSAK are swapped. I'll fit it in the next batch of PCBs. 4. I've been "scheming" for a way to add a video/keyboard "terminal" card. I have several designs, none of which I'm entirely happy with. We can discuss them if anyone's interested. 5. A customer found a bug in the Dunfield BASIC; it can crash when handling strings. I haven't had time to track this one down yet. Anybody? What have YOU been doing with the Z80MC? Lee Hart -- If happiness is on your mind, here's a daily list to find: - something to do - something to look forward to - someone to love - someone to take good care of - and misbehave, just a little -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com |
