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Comparing writing “Hello World” using DDT versus ASM in CP/M
- 29 September 2024
Using DDT, one can use the inline assembler to write small programs.
Besides DDT, CP/M also offers ASM to assemble a bit more
advanced programs. In this blogpost, I will use both programs to write a small
“Hello World” program and compare the workflow between the two procedures.
Driving serial communication in CP/M on the P2000C using Z80 assembly
- 22 September 2024
The Philips P2000C, despite allowing for a 8088-CoPower Board, was in the first place a CP/M machine. CP/M (Control Program for Microcomputers) was an early operating system developed by Gary Kildall in 1974 for Intel 8080 microcomputers. It became one of the first widely used OS for personal computers, providing essential features like file management, device input/output control, and program execution. CP/M was particularly influential because it allowed software to run on different hardware platforms, establishing an early form of software portability. It laid the groundwork for future operating systems and influenced the development of MS-DOS, which became dominant in the 1980s. CP/M’s impact is significant in the history of personal computing.
Using HESmon64 to program Hello World in 6502 assembly
- 14 September 2024
A while back, I showed how to build a “Hello World” program in 8088-assembly on a P2000C. Here, I would like to show how we can achieve the same thing for the C64. In contrast to the P2000C with its 8088 CoPower expansion board, the C64 hosts a 6502 processor and as such, we have to write the Hello World in 6502-assembly. Similar as to how we programmed on the P2000C, here, we will also be using a so-called monitor program.
A C64 Multicartridge
- 07 September 2024
The expansion port, located at the back of the Commodore 64, was designed to allow the computer to interface with a variety of external devices and accessories. One of the most popular uses of this port was the ability to load software programs via cartridges. Unlike the traditional method of loading programs from floppy disks or cassette tapes, which could be slow and cumbersome, cartridges offered a faster and more convenient alternative.
My Commodore 64 collection
- 03 September 2024
The Commodore 64 (C64) is a legendary home computer released in 1982, known for its affordability, robust hardware, and extensive software library. With its iconic 8-bit architecture, 64 KB of RAM, and advanced graphics and sound capabilities for its time, the C64 became one of the best-selling computers of all time, influencing the development of the gaming and computer industries in the 1980s and beyond.
A file transfer program for the P2000C / CoPower board
- 01 September 2024
In the previous two blogposts I discussed how we can use the serial port on the P2000C to exchange data between the venerable P2000C and a modern computer. So far, we were mainly exchanging short message strings, but a more valid use case is to transfer program files from a modern computer to the P2000C such that we can run these programs on the P2000C. This would also allow for cross-compilation on a modern computer and run the result on the P2000C.
Transmitting data to the Philips P2000C
- 23 August 2024
In the previous blogpost it was shown how data can be sent from the P2000C to a modern computer. In this post, we will look into how we can reverse the process and transmit data from a modern computer to the P2000C.
Serial communication with the Philips P2000C
- 17 August 2024
The Philips P2000C hosts a DB25 serial interface connector on its back side which can be used for serial communication according to the RS-232 protocol. This blog post will look into more detail how this protocol works and how we can drive the serial interface port using MS-DOS interrupt routines.
Writing 8088 assembly on the Philips P2000C
- 11 August 2024
Roughly two weeks ago, I visited the Helmond Computer Museum and was extremely lucky to find they had a Philips P2000C up for sale. A so-called luggable, in a way a predecessor of current laptops, designed by the Philips electronics company. The computer hosts a Zilog Z80A processor running at 4 MHz.
My first computer
- 07 August 2024
I have very fond memories of the Philips P2000T as it was the first computers I worked with as a kid. The year was 1993 and things were different back then. Although almost every household had a television and a telephone, computers were relatively rare. People were actively doubting whether this computer thing would really catch on or whether this was a temporary hype.
