Now that we can read SD cards and have an I/O interface in place from the Z80 to do I/O mapped access to the SD card it's time to hook the two pieces together. To do this we will need to look closer at how Grant's code request blocks. The loader...
For some reason the 47 pF value for the caps is sitting in my mind. Either after 'calibration' the LC meter is so far off that it read both my TI-89's and my V200's caps 51 pf, both ~8% high, or both of them are within their 10% tolerance and reading...
Putting everything together also requires checking everything separately first. So I did with the MiCS-VZ-89T sensor, and here is the story, also presented on my blog: MiCS-VZ-89 Air Quality SensorA low power sensor that can measure at the same time...
Digging into SD card writes means shifting gears from the Boot BIOS source code since the Boot BIOS code only does reads. The CP/M BIOS code (CBIOS128.LST) which does the reads/writes after booting. Here's the BIOS code for writes to the SD Card: 0754...
Indeed, immediately after running the Windows software in a VM with the device connected I was getting a live data log of the CO₂ concentration! This screenshot shows me breathing into the vicinity of the sensor:Ok, time to disconnect the device from...
Requirements Easily found when misplacedBig enough to hold easily but not too big that it's cumbersomeShould have a battery compartment so that unskilled personnel can replace batteries without having to open up the housingRoom enough for the necessary...
MIKBUG (Smithbug) has the following case-sensitive commands. ; V VIEW MEMORY; E CHANGE MEMORY; M MOVE MEMORY; I FILL MEMORY; F FIND ; D DISASSEMBLE CODE; & S1 LOAD PROGRAMME; G GO TO PROGRAM; J JUMP TO TARGET PROGRAM ; T TRACE PROGRAM; K CONTINUE...
FlexSEA-Plan is an embedded computer used for high-level computing. It boasts a powerful processor and can run an operating system such as Linux. Developing code on this platform is similar to the regular (i.e. non-embedded) software development process....
I've redesigned the way screens/apps are handled and introduced a main menu. More importantly, I have managed to get the average current consumption down to 350-550uA (1.5mA previously)! Turns out a huge chunk of it - 800uA, was a bug in the TWI (I2C)...
Before I began the layout of the DDL4-CPU, I came up with an initial Instruction Set Architecture (ISA) for the design. It went through several revisions as I was designing the boards and refined the components. Here at the last minute as I am...
I did another test with the rev1 prototype, this time only measuring voltage, and bringing it all the way to the maximum voltage of 60V. Again I am doing calibration and comparison to my Fluke 101 Multimeter. This has a problem as the Fluke 101 does...
Looking at the registers I noticed something. the first 24 bytes look like they have data and the last 6 bytes look like they have data. This looks like what a WII peripheral in encrypted mode would look like. The fixed 8 byte pattern repeating every...
On my TI-89, one of the battery contacts on the PCB was heavily corroded and it took a good deal of time and heat to reflow solder to make a new pad. I did this to the V200 as a preventative measure too, but I guess I heated up the nearby fuse to where...
Improving mocks I have decided to use Rust for mocking libcmfwk and libshmem_manager, as it is the language I am most comfortable with. By creating accurate mocks for these libraries, I aim to resolve the issue where camctld hangs while trying to send...