I'm going to create a stand-alone PSoC project to use the PSoC to read SD cards. I'm going to start with the hardware defines for this project (which should leave the Z80 hardware pins unmolested) and just not download code. For the software piece, I...
Detecting and identifying a card As stated in an earlier log, the card insertion is detected by grounding the pin *CD. But this is not enough to make the scope believe he have a know card inside him. You need to indicate him what type of card was inserted....
Place View Count Followers Comments Skulls Project Author 1 32400 415 56 148 Bench Power Supply The Big One 2 19900 370 38 142 3D Printable Robot Arm Andreas Hoelldorfer 3 48300 273 112 120 Luka EV MW Motors 4 4600 101 20 114 Eye Controlled Wheelchair!...
Soldered up the one-shot circuitry. I'm now calling this sdramThing3.5, as it is no longer backwards-compatible with the old code without removing the chips from their sockets and jumpering some pins...There are two types of one-shots necessary:The Chip-Select...
Motorola has published Application Note ANE426 describing a minimal system based on the MC68030.It consists of the following:MC68030 running at 20 MhzMC68681 Dual UARTMC68230 Parallel Interface / Timer8 x 6164 8 KB SRAM2 x 27512 64 KB EPROMPAL16L8 for...
It started about 3 years ago with viewing the Ben Eater series on building a simple CPU with just breadboards and TTL. Although the 74's are "relativly cheap", there are lots of them, and the total expenditure kept me back. Ben Eater sells the kit, but...
I'm going to document a few places where I'm consciously cutting corners on the design. Here's the first issue - my one-shot circuit for resetting the address counter on the rising edge of Vsync is a poor design. I think it will work, but it's not done...
Two posts ago our CPU was demonstrated connected to an Arduino to provided memory-mapped I/O. This MMIO space could hold code, other board-level I/O functions or perform functions on the host PC. The 'memory' area of this MMIO space was slow - each access...
8 weeks in and the CPU is running, although it's not doing anything useful yet. The initial task was to get all the timing circuits in place and measure the performance of the system. Only 10 chips are needed to implement the clock circuit, program counter,...
With just a flash in mind, being not a professional and starting from zero, after 3 weeks of search and learn, the bus architecture design for A1 finally came out. At the very first beginning, project AOZORA was targeted to implement the Ibex RISC-V...
When I started working in 1986, companies usually stocked a wide range of 74LS logic chips. Programmable logic in the form of PAL chips had started to make life a lot easier by mopping up most of the small-scale logic. This reduced the amount of...
You may have noticed in previous logs, I might've gone a bit overboard in using resistors to route signals where, in a logic/gate-sense, the, maybe, more "proper" way to do these things is with e.g. bidirectional-latches (newly-discovered, to me, 74x543)...