In this project, instead of using a standard embedded processor and programming it to execute 3 tasks at hand (parsing HEX character stream, generating HEX character stream, and writing character stream to video RAM driving VGA), I created 3 independent...
Thanks to Stephen Hunt, the author of the VCPM15 utlity, it is now possible to automatically execute either CP/M-86 or CP/M-80 programs without the need of the VCPM emulator program that he wrote back in the 80s. See how in the new paragraph: "CP/M-86...
Dave at eevblog posted an excellent video series on designing custom LCDs, so I watched those a number of times. I also found another eevblog user who posted a great writeup of a replacement LCD he designed for his Tandy/Radio Shack TRS-80...
For today's game, reduced the home made inductor from 10uH to 5uH & added an LM317, so it now boosted 7V to 55V. Changed the feedback to frequency instead of duty cycle. With no load, it hit 100khz. With 2 microphones, it hit 40khz,...
I uploaded a copy of the BASIC program that ran the system. The important part was this, which I annotated what it did. With this Information and finding the interface to the spectrometer is a 48 line DIO board I was able to figure out what lines did...
Paul suggested an alternate solution, namely to turn off LEDs by setting them to high impedance instead of 0V. That way the tiny LED capacitances have no way to charge and thus no ghosting. I tried it and it works! Awesome "zero extra components" solution,...
At last, I found a bit in EC RAM that is used to enable EC ACPI, so ACPI is working now. I copied the ASL code from vendor DSDT, and now battery, AC, and lid status change can be detected by OS now.https://review.coreboot.org/#/c/19072/
NEDONAND-6 is 8 multiplexers 2:1 with common control (straight select and inverted select):Board already ordered through OSHPark:Pins description:1.1) GND - ground 1.2) O0 - output of multiplexer 0 1.3) O1 - output of multiplexer 1 1.4) O2 - output of...
Yesterday we had a lot of problems with running the Ed-2000 as fast as possible and together with the Ed-Chuck. MaxMSP kept crashing!This morning, I simply cut out the Arduino Pro Mini with FTDI serial adapter and replaced it (a bit hacky) with another...
The PROM has 1 extra input pin and 1 extra output pin. There is one clever way to use it !Extra Input Pin : BLANK if input number is 0Extra Output Pin : active if input number is 0This way, the decoders can be chained and leading 0s can be blank'ed.A...
The ROP2 and ALU part has been slowly expanding to the SUXEN but the log 70. The nexus reminds that something is missing : I have forgotten to include PC+1 (NPC) value. So another level of MUX is required, which is fortunate because I had...
Currently testing CP/M-86: The custom Bios sizes the installed RAM (128/512/1024KB) and changes the CP/M-86 available TPA accordingly. Here Turbo Pascal for CP/M-86 and Wordstar 3.3 for CP/M-86:
Fortunately most of the NASA documents are available. They can be found on-line at https://www.ibiblio.org/apollo/Documents/ The following documents are what I leaned heavily on in gaining an understanding of how this computer...
This will be a quite long log.... luckily, it will naturally stop when all 42 IC's have been explained... This will be a detailed description of the schematic. For a good understanding, first read the first log and the logs that follow...